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 1-13 are pending. Claims 1, 7-8, 11 and 13 are amended. No claims are canceled or added. Accordingly, claims 1-13 are examined herein.
Priority
The present application, filed 06/01/2022, is a 371 of PCT/ES2020/070735, filed 11/25/2020, which claims foreign priority of ESP201931066, filed 12/02/2019.
Claim Rejections - 35 USC § 112
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 1-13 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.
Regarding claim 1, the limitation reciting that the sensor surface is “biofunctionalized with a target molecule (TM) to be analyzed selected from a group consisting of a biological sample, a clinical sample, an agri-food sample and water” is unclear because the members of the recited group represent types of samples rather than molecular species suitable for surface functionalization. Accordingly, it is uncertain what specific material is immobilized on the sensor surface and how the functionalization step structurally limits the claimed method. Further, the claim recites an initial step of “measuring an interference response of an interferometric transducer” prior to recited steps of nanoparticle conjugation, separation, and contacting the conjugates with the biofunctionalized sensor surface. The claim does not clearly specify what substance, interaction, or baseline condition is being measured at this stage or how the interferometric is being operatively used to generate a meaningful detection signal, thereby rendering the operational sequence and scope of the method unclear. Additionally, the claim recites that the optical reading may be based on NP-BR conjugates and “if applicable,” NP-BR-TM conjugates, without clearly defining the respective roles of these different conjugates in producing the measured signal or the conditions under which each contributes to the detection result. This ambiguity further renders the metes and bounds of the claimed method uncertain. Accordingly, because the scope of the claimed invention cannot be determined with reasonable certainty, claim 1 is indefinite.
Furthermore, claims 2-13 depend directly or indirectly from claim 1 and therefore incorporate by reference the unclear limitations discussed above with respect to claim 1. Since the scope and operational sequence of the method recited in claim 1 cannot be determined with reasonable certainty, the metes and bounds of the subject matter recited in dependent claims 2–13 likewise cannot be determined. Accordingly, claims 2–13 are indefinite.
Regarding claims 10-13, claims 10 and 12 recite the limitation "wherein the optical sensor is a Fabry-Perot interferometer." There is insufficient antecedent basis for this limitation in the claims. Specifically, independent claim 1 recites an “interferometric transducer” but does not recite an “optical sensor.” Since the term “optical sensor” lacks antecedent basis in claim 1, it is unclear whether the recited optical sensor corresponds to the interferometric transducer of claim 1 or represents a different structural element. Accordingly, the scope of claims 10 and 12 is uncertain. Additionally, claims 11 and 13 depend respectively from claims 10 and 12, and therefore inherit this indefiniteness.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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 for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. 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, 4, 5, 6, 7, 8, 9, 12, and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Ymeti et al. (Fast, Ultrasensitive Virus Detection Using a Young Interferometer Sensor. Nano Letters. Vol. 7, No. 2, February 2007) in view of Tseng et al. (Gold-Nanoparticle Enhanced in-Situ Immunosensor Based on Fiber-Optical Fabry-Perot Interferometry. 5th IEEE Conference on Nanotechnology. Vol. 2, 2005 – Non-Final dated 06/04/2025) and Peterson et al. (Enhanced Sandwich Immunoassay Using Antibody-Functionalized Magnetic Iron-Oxide Nanoparticles for Extraction and Detection of Soluble Transferrin Receptor on a Photonic Crystal Biosensor. Biosensors & Bioelectronics. Vol. 74, December 2015 – Non-Final dated 06/04/2025).
Regarding claim 1, Ymeti et al. teaches an optical interferometric biosensing method using a Young interferometer sensor for detecting biological analytes. In particular, Ymeti et al. states that “we report the application of an integrated optical Young interferometer sensor for ultrasensitive, real-time, direct detection of viruses” (Abstract, page 394). Ymeti et al. further teaches “detection of HSV-1 virus particles was performed by applying the virus sample onto a sensor surface coated with a specific antibody against HSV-1” (Abstract, page 394). Additionally, Ymeti et al. teaches the interferometric detection principle, stating that “specific analyte binding to the antibody-coated waveguide surface, which is probed by the evanescent field of the guided modes, causes a corresponding phase change that is measured as a change in the interference pattern” (paragraph 2, page 395). Lastly, Ymeti et al. teaches that optical phase change corresponds to refractive-index related sensing stating that “an estimation of the number of captured HSV-1 particles can be made given the size (150-200 nm) and the refractive index (~1.41). This results in a phase change of ~1.1 x 10-4 fringes for the binding of a single virus particle” (paragraph 1, page 397). Here, Ymeti et al. teaches that interferometric phase change is directly determined by the refractive index of captured particles on the sensor surface, thereby teaching determination of an optical reading corresponding to refractive-index-induced signal variation.
Although Ymeti et al. teaches the following: an optical detection method, interferometric transducer (Young interferometer), biofunctionalized sensing surface, and determination of optical reading based on refractive-index-related interference change – Ymeti et al. does not teach the following: contacting a sample in liquid with functionalized nanoparticles to form NP-BR-TM conjugates, separating NP-BR conjugates and NP-BR-TM conjugates from the sample, and subsequently contacting such separated nanoparticle conjugates with the interferometric sensor surface.
On the other hand, Tseng et al. teaches interferometric nanoparticle-enhanced immunosensing. Specifically, Tseng et al. states that “this paper proposes a novel method employing gold-nanoparticle to enhance optic fiber Fabry-Perot (F-P) interferometry signal and applied to immunoassay of rabbit IgG and anti-rabbit Ig” (Abstract, page 1), and “the gold nanoparticles can change cavity length in the Fabry-Perot cavity when nanoparticle conjugated bio-sample immobilized on the sensors” (Introduction, paragraph 2, page 1). Tseng et al. further teaches that “anti-rabbit IgG was assembled to gold-nanoparticles of 13 nm diameter by electric force with a rough ratio of one to one according to the estimation by Cy3 fluorescent intensity on antibody. When the fiber tip was putted into gold-anti-rabbit IgG solution with concentration of 17nM, the interfered signal was recorded (Results and Discussion, paragraph 2, page 3).
Peterson et al. teaches nanoparticle assay-workflow involving premixing and separation, stating that “the antigen-containing sample and iron oxide-nanoparticles (fAb-IONs) were “mixed first in a different tube, then after magnetic separation, removal of supernatant and resuspension in buffer, the complex was added and incubated with the capture antibody on the PC biosensor” (Materials and methods, paragraph 7, page 817). Peterson et al. further teaches that “biomarkers are magnetically separated from a complex matrix to remove non-specific binding signals; a problem often associated with biosensors’ performance at the point of care” (Conclusions, page 822).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the interferometric optical biosensing method of Ymeti et al. by incorporating the nanoparticle-conjugate immunosensing approach taught by Tseng et al. in order to increase the magnitude and detectability of the optical interference signal generated at the sensing interface, while further modifying the combined method to include the premixing and separation workflow taught by Peterson et al. so as to enhance analytical specificity, improve signal-to-noise ratio, and reduce nonspecific binding prior to optical interrogation. A PHOSITA would have recognized that introducing nanoparticle-based signal amplification into the interferometric sensing configuration of Ymeti et al. would predictably enhance detection sensitivity because nanoparticles are known to increase effective optical path perturbation, scattering cross-section, and local dielectric loading at the sensing interface, thereby producing larger measurable phase shifts or interference signal variations. Ymeti et al. teaches an interferometric optical biosensor that detects analyte binding events by monitoring phase changes in an interference pattern caused by refractive-index perturbations near a biofunctionalized waveguide surface and Tseng et al. teaches that functionalized nanoparticles bearing specific bioreceptors can form conjugates with target biomolecules and that immobilization of such nanoparticle conjugates at an interferometric sensing region produces measurable changes in interferometric optical response. Furthermore, Peterson et al. teaches that forming nanoparticle–biomolecule conjugates in solution prior to sensing, followed by magnetic separation and removal of unbound species, provides significant advantages in reducing nonspecific background interference and improving assay accuracy when using optical biosensor platforms. A PHOSITA would therefore have been motivated to adapt the premixing and separation workflow of Peterson to the interferometric nanoparticle sensing context suggested by the combination of Ymeti et al. and Tseng et al. in order to improve assay robustness and analytical reliability. Such adaptation would represent the application of a known immunoassay processing technique to an interferometric optical biosensor environment for the predictable purpose of enhancing detection performance, which is consistent with well-established trends in biosensor development toward integrating signal amplification strategies with improved sample preparation methodologies. In view of these teachings, the combined use of interferometric detection principles (Ymeti et al.), nanoparticle-enhanced optical sensing (Tseng et al.), and premix-separation assay workflows (Peterson et al.) would have constituted a logical and technically coherent modification directed toward improving the sensitivity, selectivity, and overall analytical performance of optical biosensing methods prior to the effective filing date of the claimed invention.
Lastly, a PHOSITA would have had a reasonable expectation of success in making this modification because each reference demonstrates compatible optical biosensing mechanisms based on well-understood physicochemical principles governing biomolecular binding, refractive-index perturbation, and optical signal transduction. Combining nanoparticle signal-amplification strategies with interferometric sensing architectures and established sample-preparation workflows would yield predictable improvements in optical detection performance. The underlying physical interactions involved—namely, antibody-antigen binding, nanoparticle surface functionalization, refractive-index-dependent optical phase modulation, and magnetic separation of bound complexes—were well characterized and routinely implemented in the biosensor field prior to the effective filing date. Consequently, integrating these known techniques into a single detection method would have involved no more than the application of ordinary skill to achieve a predictable enhancement in analytical sensitivity and reliability, rather than requiring undue experimentation or inventive insight. Accordingly, a skilled artisan would reasonably have expected that modifying the interferometric biosensing method of Ymeti et al. in view of Tseng et al. and Peterson et al. would successfully produce a nanoparticle-enhanced interferometric detection method capable of determining optical signal variations arising from the presence of target biomolecules on a functionalized sensor surface.
Regarding claim 4, Ymeti et al. teaches detection of biological analytes in a clinical sample matrix, stating that “we show that the Young interferometer sensor can specifically and sensitively detect HSV-1 at very low concentrations (850 particles/mL). We have further demonstrated that the sensor can specifically detect HSV-1 suspended in serum” (Abstract, page 394). Here, Ymeti et al. teaches performing optical detection of a target molecule in a clinical sample selected from the recited group.
Regarding claims 5 and 6, Ymeti et al. teaches that the interferometric optical biosensing method is applicable to diagnostic detection of clinically relevant biological analytes. Specifically, Ymeti et al. states that “we have further demonstrated that the sensor can specifically detect HSV-1 suspended in serum. Extrapolation of the results indicates that the sensitivity of the sensor approaches the detection of a single virus particle binding, yielding a sensor of unprecedented sensitivity with wide applications for viral diagnostics” (Abstract, page 394). Furthermore, Ymeti et al. teaches antibody-based interferometric detection of protein analytes, stating that “we have recently developed a very sensitive antibody-based sensor for specific detection of, e.g., proteins. The sensor principle is based on a Young interferometer (YI) and requires no labeling of analyte molecules. The sensitivity of 10-8 refractive index units, corresponding to approximately a protein mass coverage of 20 fg/mm2, is among the most sensitive sensors reported.” (paragraph 3). These teachings demonstrate that the interferometric sensing method is suitable for detecting biological targets used in diagnostic applications and for detecting protein analytes recognized through immunological binding interactions.
Regarding claim 7, Peterson et al. teaches that nanoparticle-based optical biosensing assay steps are performed at room temperature within the claimed range. Specifically, Peterson et al. discloses that for the preparation of the PC biosensor “each well was incubated for 1 h at 23°C in a solution of 0.1M NaOH, before sonication for 15 min. After aspiration and blotting, wells received 15 mL of 2.5% GTPMS and 10mM acetic acid in ethanol solution and were left to incubate for 1 h at 23 °C” (Materials and methods, paragraph 2, page 817). Next, for capture monoclonal antibody immobilization, “an aliquot of 15 μL at 40 μg/mL of capture anti-sTfR antibodies was dispensed into all epoxy-silanized wells. The PC microplate was sealed with tape and left at 23 °C for 5 h” (Materials and methods, paragraph 3, page 817). Additionally, “the mixture of fAb-IONs and sTfR was incubated at room temperature (23 °C) on a shaker (400 rpm) for 1 h before magnetic separation was applied using the SuperMag Multitube Separator™ (Ocean NanoTech) for 1 h in 1.5 mL micro-centrifuge tubes” (Materials and methods, paragraph 7, page 817). These disclosures teach conducting nanoparticle-assisted optical biosensor assay procedures at temperatures squarely within the claimed range.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to conduct the optical measurement step and the conjugate-processing / separation step of the interferometric nanoparticle-based detection method under conventional ambient assay temperature conditions as expressly taught by Peterson et al. Peterson et al. teaches that nanoparticle-assisted immunoassay preparation steps, including surface functionalization, antibody immobilization, analyte incubation, and magnetic separation handling, are routinely performed at approximately room temperature (e.g., about 23 °C), which falls within the claimed temperature range of 0–40 °C. A PHOSITA implementing the interferometric biosensing workflow would have been motivated to adopt such routine laboratory temperature conditions to ensure stable antibody-antigen interaction kinetics, maintain structural integrity of biological recognition elements, and promote consistent optical signal generation. Optical biosensor assays are commonly standardized to operate within ordinary laboratory temperature ranges because such conditions provide predictable biomolecular binding behavior and reliable instrumental performance. Lastly, a PHOSITA would have had a reasonable expectation of success in in applying these conventional temperature conditions because interferometric biosensor signal generation mechanisms, including binding-induced refractive-index or phase changes at a sensing interface, operate predictably under moderate laboratory temperature environments. The claimed temperature range broadly encompasses typical assay handling conditions and therefore represents no more than routine optimization of known biosensing parameters.
Regarding claim 8, as discussed above, Peterson et al. teaches nanoparticle-assisted immunoassay workflows in which formed nanoparticle-biomolecule conjugates are separated from the sample matrix using magnetic separation technique. Specifically, Peterson et al. states that “the mixture of fAb-IONs and sTfR was incubated at room temperature (23 °C) on a shaker (400 rpm) for 1 h before magnetic separation was applied using the SuperMag Multitube Separator™ (Ocean NanoTech) for 1 h in 1.5 mL micro centrifuge tubes” (Materials and Methods, paragraph 7, page 817).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate a magnetic separation technique into the nanoparticle-assisted optical detection workflow in view of Peterson et al. Peterson et al. teaches that magnetic nanoparticle probes may be used to selectively capture target analytes from liquid samples and that magnetic field-based separation can be applied to isolate nanoparticle–biomolecule conjugates prior to optical sensing. A PHOSITA would have been motivated to adopt such magnetic separation processing in order to reduce nonspecific background signals, improve analyte enrichment, and enhance the signal-to-noise ratio of the subsequent optical measurement. Magnetic separation represents a well-established sample-handling step in immunoassay-based biosensing systems and therefore would have constituted a predictable design choice for improving assay selectivity and measurement reliability. Lastly, a PHOSITA would have had a reasonable expectation of success in making this modification because the capture and isolation of nanoparticle–biomolecule conjugates using magnetic force is a mature and widely practiced analytical technique that does not interfere with downstream optical biosensor detection. Accordingly, incorporating the magnetic separation approach taught by Peterson et al. would have been an obvious and technically feasible modification of the claimed method.
Regarding claim 9, Tseng et al. expressly teaches the use of gold nanoparticles in interferometric nanoparticle-based biosensing. Specifically, Tseng et al. states that “in the sensor preparation, cysteine molecules were immobilized on the sensor surface to allow attachment of gold-nanoparticles” (Abstract, page 1). This disclosure teaches a metallic nanoparticle material falling squarely within the group of nanoparticle materials recited in claim 9. Also, Peterson et al. teaches the use of magnetic iron-oxide nanoparticles as immunoassay probes in optical biosensing workflows. Specifically, Peterson et al. states that “in this study, iron-oxide nanoparticles (fAb-IONs) were used as magnetic immuno-probes to bind sTfR and minimize non-specific signals, while enhancing detection on the PC biosensor” (Abstract, page 815). This disclosure teaches nanoparticles composed of magnetic materials and metal oxides, which are also encompassed within the group of nanoparticle materials recited in claim 9.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to implement the interferometric nanoparticle-assisted optical detection method using nanoparticle materials such as metallic nanoparticles (e.g., gold) or magnetic metal-oxide nanoparticles (e.g., iron-oxide) as respectively taught by Tseng et al. and Peterson et al. Tseng et al. teaches the use of gold nanoparticles in interferometric sensing configurations to enhance optical signal sensitivity, while Peterson et al. teaches that magnetic iron-oxide nanoparticles functionalized with biological recognition elements may be used as immuno-probes for analyte capture and subsequent optical detection. A PHOSITA would have recognized that nanoparticle material composition represents a routine design variable selected based on known physicochemical properties such as optical signal enhancement capability, magnetic manipulability for sample handling, surface functionalization compatibility, and overall assay integration considerations. Since the prior art demonstrates that both metallic and magnetic nanoparticle materials are commonly employed in biosensing systems to facilitate analyte binding and improve detection performance, selecting nanoparticle materials from among known metallic, dielectric, magnetic, or metal-oxide compositions would have constituted a predictable substitution guided by established engineering and assay-design considerations. Lastly, a PHOSITA would have had a reasonable expectation of success in selecting nanoparticle materials from among known metallic, magnetic, dielectric, or metal-oxide compositions for use in the interferometric optical detection workflow because the functional role of nanoparticles in such biosensing workflows—namely participation in analyte recognition events and contribution to measurable optical signal changes at a sensing interface—was well understood in the art. The teachings of Tseng et al. and Peterson et al. collectively demonstrate that different nanoparticle material classes may be successfully integrated into optical biosensor platforms without impairing detection operability. Accordingly, selecting nanoparticle materials within the claimed group would have represented routine optimization of known biosensor design parameters rather than an inventive modification.
Regarding claims 12 and 13, Tseng teaches the use of gold nanoparticles in a Fabry-Perot interferometric optical sensing configuration, stating that “In this paper, we proposed a novel method by employing gold-nanoparticles in Fabry-Perot interferometry on optic fiber sensor to enhance signal sensitivity” (Introduction, paragraph 2, page 1). Tseng et al. further teaches nanoparticle size optimization for interferometric sensing performance, stating that “a novel method to enhance Fabry-Perot signal by employing gold- nanoparticles has been demonstrated in this research. Experiment result shows that 40nm gold-particles could get the best signal strength and improves the sensitivity to reach the detection limit of 107 particles/µl, one order of magnitude lower than that of traditional ways by Fabry-Perot method” (Conclusions, page 4).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ a Fabry-Perot interferometric sensing configuration together with gold nanoparticles having sizes and concentrations within known signal-enhancing ranges as taught by Tseng et al. Tseng et al. teaches that Fabry-Perot interferometric optical sensing configurations may utilize gold nanoparticles to enhance measurable optical signal modulation and detection sensitivity, and further demonstrates that nanoparticle size is a performance-affecting parameter, identifying approximately 40 nm gold nanoparticles as providing improved interferometric signal strength. A PHOSITA would have been motivated to adopt such nanoparticle size selection principles in order to increase interferometric response magnitude arising from nanoparticle-associated binding events at a sensing interface. Tseng et al. further demonstrates that detectable Fabry-Perot responses occur at nanoparticle loading levels corresponding to workable concentration regimes, thereby providing guidance that nanoparticle concentration constitutes a recognized result-effective variable influencing optical signal strength and assay sensitivity. Selection or adjustment of nanoparticle concentration within an operable range to balance signal enhancement, surface coverage, and assay robustness would therefore have represented routine optimization of known biosensor design parameters. Lastly, a PHOSITA would have had a reasonable expectation of success in implementing this modification because interferometric optical biosensing signal modulation arising from nanoparticle binding was known to scale predictably with nanoparticle optical interaction properties, including size-dependent scattering behavior and surface loading density. Tseng et al. provides experimental confirmation that gold nanoparticles within the disclosed size regime produce measurable Fabry-Perot interferometric signal enhancement, demonstrating the feasibility of improving optical detection performance through nanoparticle parameter selection. Accordingly, implementing gold nanoparticles having sizes and concentrations within the claimed ranges would have constituted a predictable refinement of known interferometric biosensor configurations rather than an inventive modification.
Claims 2 and 3 are rejected under 35 U.S.C. 103 as being unpatentable over Ymeti et al., Tseng et al., and Peterson et al. as applied to Claim 1 above, and further in view of Espinosa et al. (A Proof-of-Concept of Label-Free Biosensing System for Food Allergy Diagnostics in Biophotonic Sensing Cells: Performance Comparison with ImmunoCAP. Sensors. Vol. 18, No. 8, August 2018 - Non-Final dated 06/04/2025).
With respect to the teachings of Ymeti et al., Tseng et al., and Peterson et al., see the discussion above, which applies equally here. These references differ from the instant claims in failing to teach that the target molecule is an IgE allergy-specific antibody specific to an allergenic molecule (claim 2), nor that the sensor surface is functionalized with an allergenic molecule specific for an allergy-specific antibody (claim 3).
However, Espinosa et al. teaches optical biosensing detection of allergy-related IgE antibodies, stating that “immunoglobulin type E (IgE) biomarker determination in human serum is a typical in vitro test for allergy identification. In this work, we used a novel biosensor based on label-free photonic transducers called BICELLs (Biophotonic Sensing Cells) for IgE detection. (Abstract, page 1). Espinosa et al. further teaches interferometric optical biosensing platforms for such allergy diagnostics, stating that “the read-out platform works in a label-free format by reading the interferometric signal of each BICELLs and measuring the binding events that take place on them” (Introduction, paragraph 4, page 2). Lastly, Espinosa et al. teaches allergen-based surface functionalization strategies used in allergy diagnostics, disclosing that “commercial in vitro tests use immunochemical techniques based on immobilization of the allergen on solid phase or over different surfaces, such as microplates, microarrays, capsules, and membranes. The sample (human serum) is incubated over the surface, waiting for the IgE binding of those components to which the patient is sensitized” (Introduction, paragraph 2, page 2).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to modify the interferometric optical biosensing method of Ymeti et al., as further refined by the nanoparticle-assisted sensing and assay-workflow teachings of Tseng et al. and Peterson et al., to specifically detect IgE allergy-related antibodies and to functionalize the sensing surface with allergenic molecules as taught by Espinosa et al. Espinosa et al. teaches that IgE antibodies directed toward specific allergenic molecules represent clinically significant diagnostic biomarkers and that interferometric optical biosensor platforms may be configured to detect such allergen–IgE binding interactions through immobilization of allergenic capture ligands on the sensing surface. A PHOSITA would have been motivated to incorporate allergen-specific binding chemistry into the interferometric detection method in order to extend the known biosensing platform to clinically relevant allergy diagnostics. Substituting one known antigen-antibody recognition system for another within an otherwise unchanged optical detection architecture would have represented a predictable design choice based on well-established immunodiagnostic principles and widespread clinical demand for sensitive allergy testing. Lastly, a PHOSITA would have had a reasonable expectation of success in making this modification because interferometric optical biosensors were known to detect binding-induced refractive-index changes associated with antibody–antigen adsorption events, and Espinosa et al. demonstrates that allergen–IgE interactions can be successfully implemented within interferometric sensing configurations. Accordingly, adapting the detection method to employ allergenic capture molecules for IgE biomarker detection would have constituted routine application of known immunochemical assay design practices rather than an inventive modification.
Claims 10 and 11 are rejected under 35 U.S.C. 103 as being unpatentable over Ymeti et al., Tseng et al., and Peterson et al. as applied to Claim 1 above, and further in view of Sun et al. (A Nonenzymatic Optical Immunoassay Strategy for Detection of Salmonella Infection Based on Blue Silica Nanoparticles. Analytica Chimica Acta. Vol. 898, October 2015) and Rocco et al. (Site-Specific Labeling of Surface Proteins on Living Cells Using Genetically Encoded Peptides That Bind Fluorescent Nanoparticle Probes. Bioconjugate Chemistry. Vol. 20, No. 8, August 2009).
With respect to the teachings of Ymeti et al., Tseng et al., and Peterson et al., see the discussion above, which applies equally here. Although Tseng et al., teaches nanoparticle-enhanced interferometric sensing using a Fabry-Perot interferometric optical configuration – collectively, Ymeti et al., Tseng et al., and Peterson et al., differ from the instant claims in failing to teach the use of spherical silica nanoparticles having a diameter between 50 nm and 100 nm as recited in claim 10, nor the use of nanoparticle concentrations within the specific numerical range recited in claim 11.
However, Sun et al. teaches silica nanoparticles having sizes within the claimed dimensional range and their use in optical immunoassay detection systems. Specifically, Sun et al. states that “a novel nonenzymatic optical immunoassay strategy was for the first time designed and utilized for sensitive detection of antibody to Salmonella pullorum and Salmonella gallinarum (S. pullorum and S. gallinarum) in serum. The optical immunoassay strategy was based on blue silica nanoparticles (Blue-SiNps) and magnetic beads (MB)” (Abstract, page 109). Sun et al. further teaches that “the Blue-SiNps were extremely uniform in size, with the average diameter of 50 ± 2 nm determined by SEM” (Results and Discussion, paragraph 1, page 111).
Rocco et al. teaches nanoparticle concentrations within the numerical range recited in claim 11 in optical biological labeling environments. In particular, Rocco et al. states that “we report a highly specific, robust, and generic method for noncovalent labeling of cellular proteins with highly fluorescent core-shell silica nanoparticles termed C dot” (Abstract, page 1482), and “normalized samples were incubated in the dark for 1 h at4°C with 30 nm TRITC C dots at a concentration of 8.1 × 108 particles/µL”(Experimental Procedures, paragraph 3, page 1483).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to modify the interferometric optical biosensing method of Ymeti et al., as further informed by the Fabry-Perot nanoparticle sensing architecture taught by Tseng et al. and the nanoparticle-mediated immunoassay handling and detection improvements taught by Peterson et al., to employ spherical silica nanoparticles having diameters within the range taught by Sun et al. and nanoparticle concentrations within the range taught by Rocco et al., in order to optimize optical signal strength and detection sensitivity in nanoparticle-assisted biosensing methods. Sun et al. demonstrates that silica nanoparticles having diameters near the claimed size range can be reproducibly synthesized with uniform morphology and functionalized for use as optical immunoassay signal labels. A skilled artisan would have recognized that nanoparticle size directly affects optical scattering efficiency and refractive-index perturbation at a sensing interface, and therefore selecting particle sizes within known workable ranges represents a predictable design choice for improving signal modulation performance. Rocco et al. further demonstrates that silica nanoparticle labeling systems operate effectively at concentrations within the claimed numerical range, thereby providing empirical guidance for selecting nanoparticle ensemble densities that produce strong and reliable optical signal responses in biological detection environments. Since nanoparticle surface density influences capture probability and cumulative optical signal magnitude, a PHOSITA would have been motivated to select concentrations within known effective ranges in order to enhance sensitivity while maintaining assay stability and minimizing nonspecific background effects. Selection of nanoparticle size and concentration within experimentally demonstrated workable regimes therefore represents routine optimization of known performance-affecting parameters in optical biosensor assay design.
Lastly, a PHOSITA would have had a reasonable expectation of success in making these modifications because the relationship between nanoparticle physical characteristics—such as size and concentration—and resulting optical signal response was well understood prior to the effective filing date. The cited references collectively demonstrate that silica nanoparticles within the claimed size range can be fabricated and functionalized for biological labeling applications and that such particles produce reliable optical signals when used at concentrations within the taught operational ranges. Accordingly, implementing nanoparticles of the taught size at known effective concentrations would have been expected to yield predictable and operable detection performance without requiring inventive experimentation.
Ultimately, for the reasons set forth above, claims 1–13 are rejected under 35 U.S.C. 103 as being unpatentable over the cited prior art combinations. In particular, the interferometric optical biosensing framework taught by Ymeti et al., as further modified by the nanoparticle-enhanced interferometric sensing teachings of Tseng et al., the nanoparticle premixing, separation, and optical detection workflow teachings of Peterson et al., and the additional teachings of Espinosa et al., Sun et al., and Rocco et al. with respect to specific dependent-claim limitations, collectively render the claimed subject matter obvious to a PHOSITA before the effective filing date of the claimed invention.
For the reasons stated above, all claims are rejected.
Response to Arguments
Applicant’s remarks filed, 12/03/2025, in response to the prior non-final Office Action have been fully considered but are not persuasive except as specifically indicated below.
Regarding objections, Applicant’s submission of a replacement abstract responsive to the prior objection is acknowledged. The objection to the abstract is withdrawn. Applicant’s amendment to claim 8 correcting the reference to the separation step from “step b)” to “step c)” is also acknowledged. The objection to claim 8 is withdrawn.
Regarding claim amendments, Applicant states that claims 1, 7–8, 11, and 13 were amended merely to place the claims in better condition for U.S. practice and not in response to the art rejections. Regardless of Applicant’s characterization of the purpose of the amendments, the claims are examined as amended. The present rejections address the claims in their current form.
Regarding claim rejections – 35 U.S.C. §112(b), Applicant’s arguments with respect to the indefiniteness rejection of claim 1 have been fully considered but are not persuasive. Although Applicant asserts that amended claim 1 now clearly recites two alternative biofunctionalization options and specifies that the interferometric transducer determines an optical reading, the claim language continues to lack clarity as to the structure and operational sequence of the recited method. In particular, the limitation reciting that the sensor surface is biofunctionalized with “a target molecule (TM) to be analyzed selected from a group consisting of a biological sample, clinical sample, an agri-food sample and water” remains unclear because the recited items in the group represent sample types rather than molecular species suitable for surface functionalization, thereby rendering the scope of the functionalization step uncertain. Further, the method still recites an initial step of “measuring an interference response” prior to recited conjugation, separation, and contacting steps, and the claim does not clearly specify what material or binding event is being measured at that stage or how the interferometric transducer is being utilized to generate a meaningful detection signal. Additionally, the continued recitation of both NP-BR conjugates and NP-BR-TM conjugates as potential contributors to the optical reading introduces ambiguity as to the operative detection mechanism and the conditions under which each conjugate produces the claimed measurement result. Applicant’s explanations in the remarks describe an intended interpretation of the claim but do not resolve the ambiguity present in the claim language itself. Accordingly, since the scope of the claimed method remains uncertain and the claim fails to particularly point out and distinctly claim the subject matter regarded as the invention, the rejection of claim 1 under 35 U.S.C. 112(b) is maintained.
Next, Applicant’s arguments with respect to the indefiniteness rejection of claim 5 have been fully considered and are persuasive. Upon further review, the limitation reciting that the target molecule is “a biomarker for in vitro diagnosis” is interpreted as defining the intended diagnostic application context of the claimed method rather than rendering the scope of the claim unclear. Although the limitation is broad, it does not prevent one of ordinary skill in the art from reasonably understanding the metes and bounds of the claimed subject matter. Accordingly, the rejection of claim 5 under 35 U.S.C. §112(b) is withdrawn.
Regarding claim rejections – 35 U.S.C. §102, Applicant’s arguments traversing the prior anticipation rejection over Kim et al. have been considered. In view of the amendments to claim 1 and the adoption of new obviousness grounds based on Ymeti et al. as the primary framework, the prior § 102 rejection over Kim et al. is withdrawn. Accordingly, Applicant’s arguments directed specifically to anticipation by Kim et al. are moot.
Regarding claim rejections – 35 U.S.C. §103, Applicant’s arguments against the prior obviousness rejections based on Kim et al., Yaremchuk et al., Naimushin et al., Tseng et al., Peterson et al., and Sun et al. have been considered. To the extent those arguments were directed to the previously stated non-final rejections, they are moot because the present final rejection no longer relies on Kim et al. as the primary reference and no longer relies on the prior non-final rationale. The current obviousness analysis instead relies on Ymeti et al. as the primary reference, with Tseng et al., Peterson et al., Espinosa et al., Sun et al., and Rocco et al. applied for specific additional limitations as set forth in the present action.
Conclusion
Applicant’s amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. 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 mailing date of this final action.
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/E.O./Examiner, Art Unit 1677
/BAO-THUY L NGUYEN/Supervisory Patent Examiner, Art Unit 1677
March 18, 2026