DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Status of the Claims
Claims 1-20 were pending. Claims 5-6 are canceled. Claims 21-22 are added.
Claims 1-4 and 7-22 are examined herein.
Claim Objections
Claims 21 and 22 are objected to because of the following informalities:
Claims 21 and 22 recite “the magnetic metal nanoparticles include at least one magnetic is cobalt”, which is grammatically incorrect.
Appropriate correction is required.
Withdrawn Rejections
The rejection of claims 5 and 6 is withdrawn in view of claims cancelation.
Claim Rejections - 35 USC § 112
Updated for new claims 21 and 22
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION. —The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-22 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claims 1 and 2 recite “a calculation step of calculating the amount of the magnetic metal nanoparticles from the total amount of current and calculating an amount of the test substance from the amount of the magnetic metal nanoparticles according to a calibration curve with current values and test substance concentrations” (last par. in each claim).
The claims state “a calculation step”, but they actually recite two calculations: “calculating the amount of the magnetic metal nanoparticles” and “calculating an amount of the test substance from the amount of the magnetic metal nanoparticles”. It is unclear how many calculations are present in the last paragraph of claims 1 and 2. Reciting two calculations is confusing because calculating the amount of the magnetic metal nanoparticles from the total amount of current (calculation #1) is an intermediate calculation that is not used for any other purpose other than the second calculation of calculating an amount of the test substance from the amount of the magnetic metal nanoparticles (calculation #2). The first calculation is an unnecessary calculation and that has no effect on the final calculation result. It is widely accepted practice in the art to avoid calculating intermediate values that are not used beyond the calculation step - calculating the amount of the magnetic metal nanoparticles from the total amount of current (calculation #1) is an example of such intermediate calculation.
Additionally, the specification discloses that “the test substance contained in the test substance solution can be accurately quantified by creating a calibration curve using a sample containing a known amount of the test substance” (pg. 17, lines 10-12). The use of a calibration curve usually means that only one calculation is actually involved - a direct calculation of an amount of the test substance from the amount of current. Two calculations would require at least two calibration curves, which is not supported by the specification, as Fig. 3 and Fig. 5 show only one calculation step in each diagram and figures 7-10 disclose direct relationship between the measured current and antigen concentration.
Claims 3-22 are rejected because they depend from rejected claims 1 and 2.
For the purpose of compact prosecution and applying prior art under 35 U.S.C. 102 and 103, the instant claims are interpreted as requiring a calculation step of calculating an amount of the test substance from the amount of current according to a calibration curve with current values and test substance concentrations. The two separate calculations indicated above as calculation #1 and calculation #2 will not be given patentable weight.
Claim Rejections - 35 USC § 103
Updated for new claims 21 and 22
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
Determining the scope and contents of the prior art.
Ascertaining the differences between the prior art and the claims at issue.
Resolving the level of ordinary skill in the pertinent art.
Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1, 3, 15, 19, and 21 are rejected under 35 U.S.C. 103 as being unpatentable over Feldbrugge et al. (IDS; US 2004/0110230) in view of Dong et al. (Interdiscip Rev Nanomed Nanobiotechnol. 2017 Sep;9(5) Epub 2017 Feb 20), Chen et al. (IDS; US 2011/0046013), and Szymanski et al. (Electroanalysis, (2010) 22 (2). pp. 191-198) and as evidenced by Wikipedia (Nickel electroplating – Wikipedia).
Regarding claim 1, Feldbrugge teaches a method for determining the concentration of analytes using metal particles as labels and an electrochemical detection technique (Abstract, [0009]-[0011]), the method comprising:
using a sensor having a working electrode, a reference electrode, and a counter electrode ([0030]) for binding the test substance via the primary antibodies fixed on a surface of the working electrode ([0039]);
detecting the test substance using a dispersion liquid of magnetic nanoparticles including conductive solvent and magnetic nanoparticles dispersed in the solvent – specifically, the reference teaches an electrolytic solution used as a solvent ([0032]). The reference also teaches secondary antibodies being fixed to surfaces of the magnetic nanoparticles ([0039] and [0025]). Feldbrugge teaches the magnetic particle has an average particle diameter in the range of 0.1 to 5 µm ([0040]), therefore the magnetic particle is a magnetic nanoparticle;
a magnetic field applying step of applying a magnetic field to the magnetic metal nanoparticles connected to the test substance in the presence of a solvent and bringing the magnetic metal nanoparticles into contact with the working electrode – specifically, Feldbrugge teaches “it is also possible to focus the particles in advance onto the electrode by means of an electrical or magnetic field and in this way to further increase the sensitivity” ([0025]);
a current amount measuring step - specifically, Feldbrugge teaches a constant potential is applied to the working electrode, electrical current flows through the solution ([0031]), and the current flow registered at the microelectrode ([0033]).
Regarding the limitation of the analysis method is performed free of re-depositing the magnetic metal nanoparticles on the working electrode, Feldbrugge does not explicitly teach omitting the re-deposition step, however the reference teaches direct dissolution of the metal present in the particles without any intermediate steps (see Fig. 3A and B). As such, the teaching of Feldbrugge meets the claim limitation.
Feldbrugge does not specifically teach the order of binding events as recited in claim 1: binding of the test substance to the antibody fixed on the working electrode, removing the test substance solution, binding the magnetic nanoparticles to the captured test substance, and removing the dispersion liquid. Instead, Feldbrugge teaches the following order of binding events: binding of the test substance to the antibody fixed on the magnetic nanoparticles and then contacting the nanoparticles with the antibody fixed on the working electrode ([0009] and [0010]).
Regarding claim 1, Dong teaches microfluidic methods performed in ELISA format (Title). Fig. 1(a) teaches sandwich assay format recited in claim 1, where a target is bound to an immobilized antibody and then a labeled secondary antibody is contacted with the immobilized target. Both approaches (Dong and Feldbrugge) are well-known in the art of sandwich immunoassays, both approaches are interchangeable, and one of ordinary skill in the art would have chosen either approach with a reasonable expectation of success.
Feldbrugge and Dong do not explicitly teach the washing steps between the binding steps. However, the washing steps are inherent to the immunoassays performed in the sandwich format and Dong teaches that wash steps are needed to remove excess unreacted antigen or antibody (pg. 2, col. 1, last par.). The wash step needed to remove excess unreacted antigen is equivalent to the first washing step of claim 1 and the wash step needed to remove excess unreacted antibody is equivalent to the second washing step of claim 1.
Feldbrugge and Dong do not specifically teach the magnetic nanoparticles being magnetic metal nanoparticles, current amount measuring step of applying a voltage between the working electrode and the counter electrode to ionize the magnetic metal nanoparticles in direct contact with the working electrode, and a calculation step of calculating an amount of the test substance from the total amount of current according to a calibration curve with current values and test substance concentrations.
Regarding claim 1, Chen teaches preparation of antibodies fixed to magnetic particles ([0056], [0057]), containing Co or Ni ([0058]), in order to provide patterning of biomolecules on a substrate for use in bioanalysis and diagnostics ([0017]). Cobalt and nickel meet the limitation of claim 1, reciting wherein the magnetic metal nanoparticles include at least one magnetic metal selected from a group consisting of iron, cobalt, and nickel.
Additionally, Chen teaches sizes of the magnetic particles - “micro- or nanoparticles may be composed of a variety of materials and may range in size from 1 nm-100 μm” ([0057]), a range falling within and therefore meeting the limitation of claim 15, which recites a range of 1 nm to 50 nm.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of Feldbrugge and Dong by employing Co or Ni in magnetic metal nanoparticle as taught by Chen, as an obvious matter of simple substitution of one known element (Co- or Ni-containing magnetic metal nanoparticle) for another (generic magnetic particle of Feldbrugge and Dong) to obtain predictable results.
Both kinds of magnetic particles preserve their magnetic properties and metals taught by Chen do not negatively affect these properties. Therefore, one of ordinary skill would have a reasonable expectation of success.
Feldbrugge, Dong, and Chen do not specifically teach current amount measuring step of applying a voltage between the working electrode and the counter electrode to ionize the magnetic metal nanoparticles in direct contact with the working electrode, and a calculation step of calculating an amount of the test substance from the total amount of current according to a calibration curve with current values and test substance concentrations.
Regarding claim 1, Szymanski teaches an electrochemical immunoassay, wherein the amount of captured silver nanoparticles acting as a label was measured by oxidizing the silver metal and detecting it by anodic stripping voltammetry (Abstract and pg. 194, col. 2, par. 4). As such, Szymanski teaches measuring current proportional to the amount of bound analyte.
Regarding a calibration curve, Szymanski teaches a calibration curve of total current values (microcoulombs) from test substance concentrations (myoglobin) (Fig. 6).
Regarding the limitation of “a calculation step of calculating the amount of the magnetic metal nanoparticles from the total amount of current and calculating an amount of the test substance from the amount of the magnetic metal nanoparticles according to a calibration curve with current values and test substance concentrations” (last par.) – the calculation step recites two calculations: “calculating the amount of the magnetic metal nanoparticles” and “calculating an amount of the test substance from the amount of the magnetic metal nanoparticles”. The first calculation as a separate calculation step is unnecessary and presenting it as a separate calculation has no effect on the final calculation result.
Since Applicant has not disclosed that the specific limitations (two separate calculations performed one after another) recited in instant claim is for any particular purpose or solve any stated problem it would have been obvious for one of ordinary skill to perform only one calculation starting with the total amount of current and finding an amount of the test substance without generating an intermediate result of the amount of the magnetic metal nanoparticles which is never used in the instant methods. Additionally, the calibration curve taught by Szymanski (Fig. 6) makes possible this single calculation step.
Szymanski does not specifically teach dissolving metals present in the magnetic particles taught by Chen. However, Wikipedia provides evidence that nickel when connected to an electric current circuit is capable of dissolving as nickel ions (Nickel electroplating – Wikipedia, pg. 1, par. 2, and the process is known since 1837 – par. 4). Therefore, Ni-containing particles taught by Chen would inherently dissolve upon applying voltage between electrodes.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of Feldbrugge, Dong, and Chen, by employing oxidation of metal present in the metal magnetic particles of Chen and electrochemical detection of ionized metals (e.g., Ni) as taught by Szymanski and evidenced by Wikipedia, in order to provide a very sensitive detection for immunoassays. One having ordinary skill in the art would have been motivated to make such a change because Szymanski teaches “high sensitivity of electrochemical immunoassays with metal nanoparticles as the bio-label is related to the release of huge number of metal ions from one single nanoparticle (i.e. 106 from 40-nm particle) and their subsequent detection at a carbon electrode using ASV” (pg. 191, col. 2, last par.). This combination would have been desirable to those of ordinary skill in the art for the reasons mentioned above.
One having ordinary skill in the art would have had a reasonable expectation of success in combining the prior art references because Feldbrugge, Dong, Chen, and Szymanski are similarly drawn to using magnetic nanoparticles in immunoassays, and detection of oxidized metal label has been demonstrated by Szymanski.
The limitation of current amount measuring step of applying a voltage between the working electrode and the counter electrode to ionize the magnetic metal nanoparticles in direct contact with the working electrode would have been obvious to one having ordinary skill in the art before the effective filing date because metal oxidation as taught by Szymanski and evidenced by Wikipedia requires direct contact with the working electrode in order for the electrical current to reach the magnetic particles.
Regarding claim 3, Feldbrugge teaches the working electrode is a metal (platinum) electrode ([0034]).
Regarding claim 19, Feldbrugge, Dong, Chen, Szymanski, and Wikipedia teach magnetic metal nanoparticles are an electrochemically measurable label for the complex of the secondary antibodies and the test substance. Feldbrugge teaches secondary antibodies being fixed to surfaces of the magnetic nanoparticles ([0039] and [0025]), and Szymanski and Wikipedia teach electrochemical method of detection (Szymanski, anodic stripping voltammetry in Abstract and pg. 194, col. 2, par. 4).
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Feldbrugge in view of Dong, Chen, Szymanski, and Wikipedia as applied to claim 1, and further in view of Cao et al. (J. Mater. Chem. C, 2016,4, 951-957), and as evidenced by Zhang (CN 104446420).
The teachings of Feldbrugge, Dong, Chen, Szymanski, and Wikipedia have been set forth above.
Feldbrugge, Dong, Chen, Szymanski, and Wikipedia fail to teach the magnetic metal nanoparticles contain sulfur.
Regarding claim 7, Cao teaches “Nonmetal sulfur-doped coral-like cobalt ferrite nanoparticles with enhanced magnetic properties” (Title). Cao also teaches magnetic particles containing sulfur. Specifically, Cao teaches preparation of sulfur-doped cobalt ferrite nanoparticles with sulfur atoms introduced during particle synthesis (pg. 952, Col.1, 1st paragraph of “Experiment section” and Fig. 1).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of Feldbrugge, Dong, Chen, Szymanski, and Wikipedia, by employing magnetic metal nanoparticles containing sulfur atoms as taught by Cao and evidenced by Zhang, in order to create magnetic metal nanoparticles with enhanced properties. One having ordinary skill in the art would have been motivated to make such a change because the sulfur-containing nanoparticles have better stability and biocompatibility (Zhang, par. 3). This combination would have been desirable to those of ordinary skill in the art for the reasons mentioned above.
One having ordinary skill in the art would have had a reasonable expectation of success in combining the prior art references because Feldbrugge, Dong, Chen, and Cao are drawn to using magnetic nanoparticles that require good biocompatibility.
Claims 9 and 11 are rejected under 35 U.S.C. 103 as being unpatentable over Feldbrugge in view of Dong, Chen, Szymanski, and Wikipedia as applied to claim 1, and further in view of Lin et al. (US 2008/0292545).
The teachings of Feldbrugge, Dong, Chen, Szymanski, and Wikipedia have been set forth above.
Feldbrugge, Dong, Chen, Szymanski, and Wikipedia fail to teach the reference electrode is a silver-silver chloride electrode.
Regarding claims 9 and 11, Lin teaches an apoferritin nanoparticle for diagnostic applications (Abstract); the apoferritin nanoparticle generating an electrochemical signal that can be measured in an electrochemical process ([0006]). Lin also teaches Ag/AgCl reference electrode and the counter electrode is a carbon electrode.
Specifically, Lin teaches a biosensor comprising a working electrode having an immobilized antibody ([0044]), an Ag/AgCl reference electrode and a carbon counter electrode ([0054]).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of Feldbrugge, Dong, Chen, Szymanski, and Wikipedia, by employing an Ag/AgCl reference electrode and a carbon counter electrode as taught by Lin, as an obvious matter of using of known technique (specific electrode materials) to improve similar methods in the same way. Ag/AgCl reference electrode and a carbon counter electrode are widely known in the art as “gold” standard electrodes with wide application range, therefore, one of ordinary skill in the art would have a reasonable expectation of success.
Claims 13 and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Feldbrugge, in view of Dong, Chen, Szymanski, and Wikipedia as applied to claim 1, and further in view of Wang et al. (Biosens Bioelectron. 2016 Jun 15; 80:640-646) and as evidenced by CSH (Cold Spring Harb Protoc; 2006; https://cshprotocols.cshlp.org/content/2006/1/pdb.rec8247).
The teachings of Feldbrugge, Dong, Chen, Szymanski, and Wikipedia have been set forth above.
Feldbrugge, Dong, Chen, Szymanski, and Wikipedia fail to teach an electrolyte of the conductive solvent is chloride.
Regarding claims 13 and 17, Wang teaches a method for the detection of thrombin using an electrochemical aptasensor (Abstract). Wang also teaches the electrolyte of the conductive solvent is chloride.
Specifically, Wang teaches the method, wherein the working solution is the PBS buffer (pg. 642, col. 2, par. 4). The PBS buffer is widely known in the art as phosphate-buffered saline solution with two chloride-containing salts present: NaCl and KCl. CSH provides evidence that PBS buffer contains 140 mM chloride (or 1.4M in 10x buffer), falling in range of chloride concentrations of claim 17, reciting 0.005 M/L to 1.0M/L.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of Feldbrugge, Dong, Chen, Szymanski, and Wikipedia, by employing a chloride-containing electrolyte as taught by Wang. One having ordinary skill in the art would have been motivated to make such a change because Wang teaches that pH optimization of the PBS buffer allows to obtain the largest current response (pg. 642, col. 2, par. 4). This combination would have been desirable to those of ordinary skill in the art for the reasons mentioned above.
One having ordinary skill in the art would have had a reasonable expectation of success in combining the prior art references because Feldbrugge, Dong, Chen, Szymanski, and Wang are drawn to detection of biological molecules using electrochemical methods, and Feldbrugge, Dong, and Chen, are generic with respect to the type of electrolytic solution in which the magnetic nanoparticles are dispersed.
Claims 2, 4, 16, 20, and 22 are rejected under 35 U.S.C. 103 as being unpatentable over Feldbrugge et al. (IDS; US 2004/0110230) in view of Dong et al. (Interdiscip Rev Nanomed Nanobiotechnol. 2017 Sep;9(5) Epub 2017 Feb 20), Chen et al. (IDS; US 2011/0046013), and Szymanski et al. (Electroanalysis, (2010) 22 (2). pp. 191-198), and Immink et al. (WO 2008/102218), and as evidenced by Wikipedia (Nickel electroplating – Wikipedia).
Regarding claim 2, Feldbrugge teaches a method for determining the concentration of analytes using metal particles as labels and an electrochemical detection technique (Abstract, [0009]-[0011]), the method comprising:
using a sensor having a working electrode, a reference electrode, and a counter electrode ([0030]) for binding the test substance via the primary antibodies fixed on a surface of the working electrode ([0039]);
detecting the test substance using a dispersion liquid of magnetic nanoparticles including conductive solvent and magnetic nanoparticles dispersed in the solvent – specifically, the reference teaches an electrolytic solution used as a solvent ([0032]). The reference also teaches secondary antibodies being fixed to surfaces of the magnetic nanoparticles ([0039] and [0025]). Feldbrugge teaches the magnetic particle has an average particle diameter in the range of 0.1 to 5 µm ([0040]), therefore the magnetic particle is a magnetic nanoparticle;
a magnetic field applying step of applying a magnetic field to the magnetic metal nanoparticles connected to the test substance in the presence of a solvent and bringing the magnetic metal nanoparticles into contact with the working electrode – specifically, Feldbrugge teaches “it is also possible to focus the particles in advance onto the electrode by means of an electrical or magnetic field and in this way to further increase the sensitivity” ([0025]);
a current amount measuring step - specifically, Feldbrugge teaches a constant potential is applied to the working electrode, electrical current flows through the solution ([0031]), and the current flow registered at the microelectrode ([0033]).
Regarding the limitation of the analysis method is performed free of re-depositing the magnetic metal nanoparticles on the working electrode, Feldbrugge does not explicitly teach omitting the re-deposition step, however the reference teaches direct dissolution of the metal present in the particles without any intermediate steps (see Fig. 3A and B). As such, the teaching of Feldbrugge meets the claim limitation.
Feldbrugge does not specifically teach the order of binding events as recited in claim 2: binding of the test substance to the antibody fixed on the working electrode, removing the test substance solution, binding the magnetic nanoparticles to the captured test substance, and removing the dispersion liquid. Instead, Feldbrugge teaches the following order of binding events: binding of the test substance to the antibody fixed on the magnetic nanoparticles and then contacting the nanoparticles with the antibody fixed on the working electrode ([0009] and [0010]).
Regarding claim 2, Dong teaches microfluidic methods performed in ELISA format (Title). Fig. 1(a) teaches sandwich assay format recited in claim 2, where a target is bound to an immobilized antibody and then a labeled secondary antibody is contacted with the immobilized target. Both approaches (Dong and Feldbrugge) are well-known in the art of sandwich immunoassays, both approaches are interchangeable, and one of ordinary skill in the art would have chosen either approach with a reasonable expectation of success.
Feldbrugge and Dong do not explicitly teach the washing steps between the binding steps. However, the washing steps are inherent to the immunoassays performed in the sandwich format and Dong teaches that wash steps are needed to remove excess unreacted antigen or antibody (pg. 2, col. 1, last par.). The wash step needed to remove excess unreacted antigen is equivalent to the first washing step of claim 2 and the wash step needed to remove excess unreacted antibody is equivalent to the second washing step of claim 2.
Feldbrugge and Dong do not specifically teach removing the magnetic nanoparticles which are not connected to the test substance from the surface of the working electrode or a vicinity thereof by an external magnetic field, the magnetic nanoparticles being magnetic metal nanoparticles, current amount measuring step of applying a voltage between the working electrode and the counter electrode to ionize the magnetic metal nanoparticles in direct contact with the working electrode, and a calculation step of calculating an amount of the test substance from the total amount of current according to a calibration curve with current values and test substance concentrations.
Regarding claim 2, Chen teaches preparation of antibodies fixed to magnetic particles ([0056], [0057]), containing Co or Ni ([0058]), in order to provide patterning of biomolecules on a substrate for use in bioanalysis and diagnostics ([0017]). Cobalt and nickel meet the limitation of claim 2, reciting wherein the magnetic metal nanoparticles include at least one magnetic metal selected from a group consisting of iron, cobalt, and nickel.
Additionally, Chen teaches sizes of the magnetic particles - “micro- or nanoparticles may be composed of a variety of materials and may range in size from 1 nm-100 μm” ([0057]), a range falling within and therefore meeting the limitation of claim 16, which recites a range of 1 nm to 50 nm.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of Feldbrugge and Dong by employing Co or Ni in magnetic metal nanoparticle as taught by Chen, as an obvious matter of simple substitution of one known element (Co- or Ni-containing magnetic metal nanoparticle) for another (generic magnetic particle of Feldbrugge and Dong) to obtain predictable results.
Both kinds of magnetic particles preserve their magnetic properties and metals taught by Chen do not negatively affect these properties. Therefore, one of ordinary skill would have a reasonable expectation of success.
Feldbrugge, Dong, and Chen do not specifically teach removing the magnetic nanoparticles which are not connected to the test substance from the surface of the working electrode or a vicinity thereof by an external magnetic field, current amount measuring step of applying a voltage between the working electrode and the counter electrode to ionize the magnetic metal nanoparticles in direct contact with the working electrode, and a calculation step of calculating an amount of the test substance from the total amount of current according to a calibration curve with current values and test substance concentrations.
Regarding claim 2, Immink teaches a method of sensing magnetic particles (Title). Immink also teaches removing unbound magnetic metal nanoparticles by an external magnetic field.
Specifically, Immink teaches a method step for attracting or repelling the magnetic particles by a magnetic force for removing unbound magnetic particles from the sensing unit (pg. 13. Lines 1-2).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of Feldbrugge, Dong, and Chen by employing external magnetic field to remove unbound magnetic metal nanoparticles as taught by Immink. One having ordinary skill in the art would have been motivated to make such a change because unbound magnetic metal nanoparticles must be removed during sandwich-format immunoassays. This combination would have been desirable to those of ordinary skill in the art because this step is required.
One having ordinary skill in the art would have had a reasonable expectation of success in combining the prior art references because Feldbrugge, Dong, Chen, and Immink are drawn to similar methods of using magnetic nanoparticles, and Feldbrugge, Dong, and Chen are generic with respect to the details of the washing steps.
Feldbrugge, Dong, Chen, and Immink do not specifically teach current amount measuring step of applying a voltage between the working electrode and the counter electrode to ionize the magnetic metal nanoparticles in direct contact with the working electrode, and a calculation step of calculating an amount of the test substance from the total amount of current according to a calibration curve with current values and test substance concentrations.
Regarding claim 2, Szymanski teaches an electrochemical immunoassay, wherein the amount of captured silver nanoparticles acting as a label was measured by oxidizing the silver metal and detecting it by anodic stripping voltammetry (Abstract and pg. 194, col. 2, par. 4). As such, Szymanski teaches measuring current proportional to the amount of bound analyte.
Regarding a calibration curve, Szymanski teaches a calibration curve with total current values (microcoulombs) and test substance concentrations (myoglobin) (Fig. 6).
Regarding the limitation of “a calculation step of calculating the amount of the magnetic metal nanoparticles from the total amount of current and calculating an amount of the test substance from the amount of the magnetic metal nanoparticles according to a calibration curve with current values and test substance concentrations” (last par.) – the calculation step recites two calculations: “calculating the amount of the magnetic metal nanoparticles” and “calculating an amount of the test substance from the amount of the magnetic metal nanoparticles”. The first calculation is a meaningless limitation and presenting it as a separate calculation has no effect on the final calculation result.
Since Applicant has not disclosed that the specific limitations (two separate calculations performed one after another) recited in instant claim is for any particular purpose or solve any stated problem it would have been obvious for one of ordinary skill to perform only one calculation starting with the total amount of current and finding an amount of the test substance without generating an intermediate result of the amount of the magnetic metal nanoparticles which is never used in the instant methods. Additionally, the calibration curve taught by Szymanski (Fig. 6) makes possible this single calculation step.
Szymanski does not specifically teach dissolving metals present in the magnetic particles taught by Chen. However, Wikipedia provides evidence that nickel when connected to an electric current circuit is capable of dissolving as nickel ions (Nickel electroplating – Wikipedia, pg. 1, par. 2, and the process is known since 1837 – par. 4). Therefore, Ni-containing particles taught by Chen would inherently dissolve upon applying voltage between electrodes.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of Feldbrugge, Dong, Chen, and Immink, by employing oxidation of metal present in the metal magnetic particles of Chen and electrochemical detection of ionized metals (e.g., Ni) as taught by Szymanski and evidenced by Wikipedia, in order to provide a very sensitive detection for immunoassays. One having ordinary skill in the art would have been motivated to make such a change because Szymanski teaches “high sensitivity of electrochemical immunoassays with metal nanoparticles as the bio-label is related to the release of huge number of metal ions from one single nanoparticle (i.e. 106 from 40-nm particle) and their subsequent detection at a carbon electrode using ASV” (pg. 191, col. 2, last par.). This combination would have been desirable to those of ordinary skill in the art for the reasons mentioned above.
One having ordinary skill in the art would have had a reasonable expectation of success in combining the prior art references because Feldbrugge, Dong, Chen, Immink, and Szymanski are similarly drawn to using magnetic nanoparticles in immunoassays, and detection of oxidized metal label has been demonstrated by Szymanski.
The limitation of current amount measuring step of applying a voltage between the working electrode and the counter electrode to ionize the magnetic metal nanoparticles in direct contact with the working electrode would have been obvious to one having ordinary skill in the art before the effective filing date because metal oxidation as taught by Szymanski and evidenced by Wikipedia requires direct contact with the working electrode in order for the electrical current to reach the magnetic particles.
Regarding claim 4, Feldbrugge teaches the working electrode is a metal (platinum) electrode ([0034]).
Regarding claim 20, Feldbrugge, Dong, Chen, Immink, Szymanski, and Wikipedia teach magnetic metal nanoparticles are an electrochemically measurable label for the complex of the secondary antibodies and the test substance. Feldbrugge teaches secondary antibodies being fixed to surfaces of the magnetic nanoparticles ([0039] and [0025]), and Szymanski and Wikipedia teach electrochemical method of detection (Szymanski, anodic stripping voltammetry in Abstract and pg. 194, col. 2, par. 4).
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Feldbrugge in view of Dong, Chen, Immink, Szymanski, and Wikipedia as applied to claim 2, and further in view of Cao et al. (J. Mater. Chem. C, 2016,4, 951-957), and as evidenced by Zhang (CN 104446420).
The teachings of Feldbrugge, Dong, Chen, Immink, Szymanski, and Wikipedia have been set forth above.
Feldbrugge, Dong, Chen, Immink, Szymanski, and Wikipedia fail to teach the magnetic metal nanoparticles contain sulfur.
Regarding claim 8, Cao teaches “Nonmetal sulfur-doped coral-like cobalt ferrite nanoparticles with enhanced magnetic properties” (Title). Cao also teaches magnetic particles containing sulfur. Specifically, Cao teaches preparation of sulfur-doped cobalt ferrite nanoparticles with sulfur atoms introduced during particle synthesis (pg. 952, Col.1, 1st paragraph of “Experiment section” and Fig. 1).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of Feldbrugge, Dong, Chen, Immink, Szymanski, and Wikipedia, by employing magnetic metal nanoparticles containing sulfur atoms as taught by Cao and evidenced by Zhang, in order to create magnetic metal nanoparticles with enhanced properties. One having ordinary skill in the art would have been motivated to make such a change because the sulfur-containing nanoparticles have better stability and biocompatibility (Zhang, par. 3). This combination would have been desirable to those of ordinary skill in the art for the reasons mentioned above.
One having ordinary skill in the art would have had a reasonable expectation of success in combining the prior art references because Feldbrugge, Dong, Chen, Immink, and Cao are drawn to using magnetic nanoparticles that require good biocompatibility.
Claims 10 and 12 are rejected under 35 U.S.C. 103 as being unpatentable over Feldbrugge in view of Dong, Chen, Immink, Szymanski, and Wikipedia as applied to claim 2, and further in view of Lin et al. (US 2008/0292545).
The teachings of Feldbrugge, Dong, Chen, Immink, Szymanski, and Wikipedia have been set forth above.
Feldbrugge, Dong, Chen, Immink, Szymanski, and Wikipedia fail to teach the reference electrode is a silver-silver chloride electrode.
Regarding claims 10 and 12, Lin teaches an apoferritin nanoparticle for diagnostic applications (Abstract); the apoferritin nanoparticle generating an electrochemical signal that can be measured in an electrochemical process ([0006]). Lin also teaches Ag/AgCl reference electrode and the counter electrode is a carbon electrode.
Specifically, Lin teaches a biosensor comprising a working electrode having an immobilized antibody ([0044]), an Ag/AgCl reference electrode and a carbon counter electrode ([0054]).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of Feldbrugge, Dong, Chen, Immink, Szymanski, and Wikipedia, by employing an Ag/AgCl reference electrode and a carbon counter electrode as taught by Lin, as an obvious matter of using of known technique (specific electrode materials) to improve similar methods in the same way. Ag/AgCl reference electrode and a carbon counter electrode are widely known in the art as “gold” standard electrodes with wide application range, therefore, one of ordinary skill in the art would have a reasonable expectation of success.
Claims 14 and 18 are rejected under 35 U.S.C. 103 as being unpatentable over Feldbrugge, in view of Dong, Chen, Immink, Szymanski, and Wikipedia as applied to claim 2, and further in view of Wang et al. (Biosens Bioelectron. 2016 Jun 15; 80:640-646) and as evidenced by CSH (Cold Spring Harb Protoc; 2006; https://cshprotocols.cshlp.org/content/2006/1/pdb.rec8247).
The teachings of Feldbrugge, Dong, Chen, Immink, Szymanski, and Wikipedia have been set forth above.
Feldbrugge, Dong, Chen, Immink, Szymanski, and Wikipedia fail to teach an electrolyte of the conductive solvent is chloride.
Regarding claims 14 and 18, Wang teaches a method for the detection of thrombin using an electrochemical aptasensor (Abstract). Wang also teaches the electrolyte of the conductive solvent is chloride.
Specifically, Wang teaches the method, wherein the working solution is the PBS buffer (pg. 642, col. 2, par. 4). The PBS buffer is widely known in the art as phosphate-buffered saline solution with two chloride-containing salts present: NaCl and KCl. CSH provides evidence that PBS buffer contains 140 mM chloride (or 1.4M in 10x buffer), falling in range of chloride concentrations of claim 18, reciting 0.005 M/L to 1.0M/L.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of Feldbrugge, Dong, Chen, Immink, Szymanski, and Wikipedia, by employing a chloride-containing electrolyte as taught by Wang. One having ordinary skill in the art would have been motivated to make such a change because Wang teaches that pH optimization of the PBS buffer allows to obtain the largest current response (pg. 642, col. 2, par. 4). This combination would have been desirable to those of ordinary skill in the art for the reasons mentioned above.
One having ordinary skill in the art would have had a reasonable expectation of success in combining the prior art references because Feldbrugge, Dong, Chen, Szymanski, and Wang are drawn to detection of biological molecules using electrochemical methods, and Feldbrugge, Dong, and Chen, are generic with respect to the type of electrolytic solution in which the magnetic nanoparticles are dispersed.
Response to Arguments
Applicant’s arguments filed December 30, 2025 have been fully considered.
Applicant argues that “Feldbrugge, Dong, Chen, Szymanski, Wikipedia, Wang, and Immink do not teach or suggest at least, a calculation step of calculating the amount of the magnetic metal nanoparticles from a total amount of current and calculating an amount of the test substance from the amount of the magnetic metal nanoparticles according to a calibration curve with current values and test substance concentrations wherein the magnetic metal nanoparticles include at least one magnetic metal selected from a group consisting of iron, cobalt and nickel, and the analysis method is performed free of re-depositing the magnetic metal nanoparticles on the working electrode as recited in claim 1 and similarly recited in claim 2” (pg. 9, par. 2).
More specifically, Applicant argues that with regards to the two calculation steps recited in claims 1 and 2, “the measured current itself does not represent the test substance quantity. In other words, the specific test substance quantity remains unknown based solely on the measured current value. Consequently, only by converting the measured current into the test substance quantity can the tester determine the specific test substance quantity” (pg. 9, par. 3). Another argument regarding the two calculation steps limitation is “Szymanski fails to teach the two calculation steps as is required by the claimed limitations, much less fails to disclose a motivation to perform the two calculation steps” (pg. 10, par. 1).
The arguments are not persuasive and unclear. By stating that “by converting the measured current into the test substance quantity can the tester determine the specific test substance quantity” Applicant actually acknowledges that there is only one calculation step leading from a measured current value to the corresponding test substance concentration. Presented arguments actually contradict the claims. Additionally, Fig. 3 and Fig. 5 show only one calculation step in each diagram and figures 7-10 disclose direct relationship between the measured current and antigen concentration.
Applicant argues that “the wherein clause recited in claim 1 and similarly in claim 2, one object of the pending application lies in omitting the re-deposition step typically involved in conventional electrochemical measurements. In contrast, Feldbrugge, Dong, Chen, Szymanski, Wikipedia, Wang, and Immink do not teach or suggest omitting the re-deposition step” (pg. 10, par. 2).
The arguments are not persuasive because “the re-deposition step typically involved in conventional electrochemical measurements” is not relied upon in the non-final OA (mailed October 1, 2025). Feldbrugge does not teach any re-deposition step or process. Although, Feldbrugge does not explicitly teach omitting the re-deposition step, the reference does teach direct dissolution of the metal present in the particles without any intermediate steps (see Fig. 3A and B). As such, the teaching of Feldbrugge meets the claims.
Applicant argues that “in the Interview Summary, the Examiner acknowledges that it would have been counterintuitive to use magnetic metal nanoparticles in the method of Feldbrugge” (pg. 10, last par.). The argument is unclear because the Interview Summary does not contain this “counterintuitive” statement.
Applicant argues that “unlike in the claimed methods, the ionization of the magnetic metal particles would render them nonfunctional as a scaffold in the method of Feldbrugge because the association between the antibodies and the magnetic particles must remain intact while the voltage is applied” (pg. 10, last par. – pg. 11, par. 1).
The argument is not persuasive and unclear because Applicant is arguing against the present invention where dissolving metal in the magnetic metal particles would render them nonfunctional as a scaffold “because the association between the antibodies and the magnetic particles must remain intact while the voltage is applied”. Applying this argument against Feldbrugge Applicant argues against instant invention because the principles of particles capture are the same in Feldbrugge and instant invention.
Applicant argues that “none of the applied references teach or suggest the application of a magnetic field to increase the sensitivity of an electrochemical method, as required by the claimed limitations” (pg. 11, par. 2).
The argument is not persuasive because Applicant is arguing limitations which are not claimed. In response to applicant’s argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., increased sensitivity of an electrochemical method) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993).
New claims 21 and 22 are rejected under §103 as being unpatentable over Feldbrugge in view of Dong, Chen, and Szymanski and as evidenced by Wikipedia (see §103 rejection above for details).
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the date of this final action.
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/ALEXANDER ALEXANDROVIC VOLKOV/
Examiner, Art Unit 1677
/BAO-THUY L NGUYEN/Supervisory Patent Examiner, Art Unit 1677 February 6, 2026