DETAILED ACTION
Response to Amendment
This is a final office action in response to a communication filed on March 3, 2026. Claims 1-2 and 6-25 are pending in the application.
Status of Objections and Rejections
All objections from the previous office action are withdrawn in view of Applicant’s amendment.
All rejections under 35 U.S.C. §103 are maintained.
New grounds of rejection are necessitated in view of Applicant’s amendment.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claim(s) 1-2, 6-9, and 24-25 is/are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for pre-AIA the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim 1 recites the limitation “wherein the blocking layer is interposed between the nanocomposite and a reporter RNA immobilized on the AuNF, thereby physically separating the reporter RNA and a Cas13a-mediated cleavage region from the nanocomposite” in lines 5-6, which is not disclosed in the specification and is deemed to be new matter. The specification only discloses SA and BSA were sequentially coated to immobilize reRNA and block the activated sensor surface, respectively (PGpub ¶135). On the surface, the gap between the immobilized SAs by BSA was filled (¶137). Thus, the specification discloses that both SAs and BSAs are deposited on the electrode surface, but only SAs are interposed between the nanocomposite and the reRNA while BSAs are filling the gap between the immobilized SAs for blocking the electrode surface. As evidenced by the prior art, Su (US 2005/0164236), streptavidin immobilized on a surface which was first reacted with a biotin-thiol molecule based on biotin-streptavidin interaction, and then BSA was applied to block any possible free gold surface that might be present due to the low biotin self-assembled monolayer coverage (¶112).
Dependent claim(s) 2, 6-9, and 24-15 is/are rejected based on rejected claim 1.
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.
Claim(s) 1-2, 6-9, and 24-25 is/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 pre-AIA the applicant regards as the invention.
Claim 1 recites the limitation "a reporter RNA (reRNA)" in line 11. It is suggested to be “the reporter RNA (reRNA).”
Dependent claim(s) 2, 6-9, and 24-15 is/are rejected based on rejected claim 1.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-2, 6-9, and 24-25 are rejected under 35 U.S.C. 103 as being unpatentable over Zhang (CRISPR/Cas12a-Mediated Interfacial Cleaving of Hairpin DNA Reporter for Electrochemical Nucleic Acid Sensing, 2020, ACS Sensors, vol. 5, pgs. 557-562) in view of Kashefi (Detachable microfluidic device implemented with electrochemical aptasensor (DeMEA) for sequential analysis of cancerous exosomes, 2020, Biosensors and Bioelectronics, vol. 169, pgs. 1-9 and pgs. 1-26 of Supporting Information (SI)), Patchsung (Clinical validation of a Cas13-based assay for the detection of SARS-CoV-2 RNA, 2020, Nature Biomedical Engineering, vol. 4, pgs. 1140-1149 and Supplementary Information), Riquelme (Optimizing blocking of nonspecific bacterial attachment to impedimetric biosensors, 2016, Sensing and Bio-Sensing Research, vol. 8, pgs. 47-54), and Smith et al. (Immobilization of Nucleic Acids Using Biotin-Strept(avidin) Systems, 2006, Topics in Current Chemistry, vol. 261, pgs. 63-90).
Zhang teaches a biosensor (CRISPR/Cas12a-based biosensor [pg. 557, Abstract]) for detecting a target DNA (target double-stranded DNA [pg. 557, col. 2, para. 1]) comprising:
an electrode with a gold surface (gold electrode in Scheme 1)
a blocking layer coated on a surface of the electrode (the electrode is immersed in 6-mercapto-1-hexanol [MCH] to block nonspecific sites [pg. 558, col. 2, para. 2]),
a reporter DNA that is immobilized on the gold surface of an electrode coated with the blocking layer (a single-stranded DNA is bonded to the gold electrode, see Scheme 1 [pg. 559, col. 1, para. 1]).
The preamble “for detecting a target RNA” is deemed to be a statement with regard to the intended use and are not further limiting in so far as the structure of the product is concerned. In article claims, a claimed intended use must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. MPEP § 2111.02(II). The apparatus as taught by modified Wynne is identical to the presently claimed structure and would therefore would have the ability to perform the use recited in the claim.
Zhang does not teach the electrode has a nanocomposite (NC) containing molybdenum disulfide (MoS2), graphene, and chitosan (CHT) and a flower-shaped gold nanostructure (AuNF) sequentially deposited on its surface.
However, Kashefi teaches an electrochemical biosensor (Abstract), in which a reporter aptamer is immobilized on an electrode (screen-printed carbon electrode [SPCE] in Fig. 3(a) [pg. 4, col. 2, para. 3]) on which a NC containing MoS2, graphene, and CHT and a AuNF are sequentially deposited (gold nanostructures are electrodeposited on a nanocomposite consisting of MoS2 nanosheets, graphene nanoplatelets, and chitosan on the SPCE, see Figs. 3(a) and 3(d) [pg. 2, col. 1, para. 5; pg. 4, col. 2, para. 3]). Kashefi further teaches that their electrode offers negligible electron-transfer resistance, well-ordered gold nanostructures, high aptamer immobilization efficiency, and biocompatibility [pg. 2, col. 1, para. 5; pg. 5, col. 1, para. 1].
Zhang and Kashefi are both considered analogous to the claimed invention because they are in the same field of electrochemical biosensors. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to substitute the gold electrode in Zhang with a AuNF/NC/SPCE, wherein the NC comprises MoS2, graphene, and CHT, as taught in Kashefi, because the substitution would offer negligible electron-transfer resistance, well-ordered gold nanostructures, high aptamer immobilization efficiency, and biocompatibility [pg. 2, col. 1, para. 5; pg. 5, col. 1, para. 1 in Kashefi]. Furthermore, the claimed device differs from Zhang by the substitution of some components (the gold electrode in Zhang) with other components (the AuNF/NC/SPCE in Kashefi) whose functions were known in the prior art. One of ordinary skill in the art could substitute one known element for another to yield predictable results (MPEP 2143(I)(B)).
Further, the limitation “an electrode on which a nanocomposite (NC) comprising molybdenum disulfide (MoS2), graphene (GNP), and chitosan (CHT), and a flower-shaped gold nanostructure (AuNF) are sequentially deposited” is considered a product-by-process limitation. The cited prior art teaches all of the positively recited structure of the claimed apparatus or product. The determination of patentability is based upon the apparatus structure itself. The patentability of a product or apparatus does not depend on its method of production or formation. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process. See In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985) (see MPEP § 2113).
Zhang does not explicitly disclose the biosensor detects a target RNA or the polynucleotide immobilized on a AuNF surface of the electrode is a reporter RNA (reRNA).
However, Patchsung teaches a CRISPR/Cas13a-based assay for the detection of target SARS-CoV-2 RNA [pg. 1140, Abstract]. In the assay, Cas13a is triggered by binding with a target RNA sequence via a target-specific crRNA, and subsequently cleaves a reporter RNA (see caption of Fig. 1 [pg. 1141]). This assay mechanism is similar to the CRISPR/Cas12a system taught in Zhang (see Scheme 1 in Zhang). Patchsung teaches that using SARS-CoV-2 RNA as the target RNA and using a reporter RNA in conjunction with the CRISPR/Cas13a system enables detection of the virus that causes coronavirus disease 2019 (COVID-19) [pg. 1140, Abstract].
Modified Zhang and Patchsung are both considered analogous to the claimed invention because they are in the same field of CRISPR/Cas-based assays. 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 biosensor in modified Zhang by substituting the target DNA in modified Zhang with SARS-CoV-2 RNA and substituting the reporter ssDNA sequence in modified Zhang with a reporter RNA sequence compatible with Cas13a, as taught in Patchsung, since this would enable detection of the virus that causes COVID-19 using a CRISPR/Cas13a-based system [pg. 1140, Abstract]. With this modification, the reporter RNA sequence is immobilized onto the AuNF surface of the electrode and has methylene blue at the 3’ terminus to maintain the electrochemical mechanism of the sensor in modified Zhang [pg. 559, col. 1, para. 1 in Zhang]. Furthermore, Patchsung teaches the claimed improvement as a known technique that is applicable to the base device in modified Zhang. One skilled in the art could have applied the SARS-CoV-2 target RNA and Cas13a-compatible reRNA in Patchsung in the same way to the base device in modified Zhang, yielding predictable results (MPEP 2143(I)(D)).
Zhang does not disclose the reRNA is immobilized on the AuNF surface of the electrode through a streptavidin-biotin bond or an avidin-biotin bond.
However, Smith teaches that nucleic acids can be immobilized onto a gold material via a streptavidin-biotin bond [pg. 79, para. 3]. Smith further teaches that the streptavidin-biotin bond offers several advantages for immobilizing nucleic acids, such as providing a stable, irreversible bond without interfering with the function of the aptamer [pg. 63, para. 1].
Modified Zhang and Smith are both considered analogous to the claimed invention because they are in the same field of nucleic acid immobilization. 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 immobilization of the reRNA in modified Zhang by immobilizing the nucleic acid via a streptavidin-biotin bond, as taught in Smith, since this would provide a stable, irreversible bond without interfering with the function of the aptamer [pg. 63, para. 1 in Smith]. Furthermore, Smith teaches the claimed improvement as a known technique that is applicable to the base device in modified Zhang. One skilled in the art could have applied the streptavidin-biotin bond in Smith in the same way to the base device in modified Zhang, yielding predictable results (MPEP 2143(I)(D)).
Zhang does not disclose wherein the blocking layer is interposed between the nanocomposite and a reporter RNA immobilized on the AuNF, thereby physically separating the reporter RNA and a Cas13a-mediated cleavage region from the nanocomposite or the blocking layer comprises a blocking agent selected from the group consisting of bovine serum albumin (BSA), skim milk, and salmon sperm DNA
However, Riquelme teaches a variety of blocking agents for reducing non-specific binding of a gold electrode with immobilized aptamers [pg. 47, col. 2, para. 2; pg. 48, col. 1, para. 1]. Riquelme further teaches that using BSA is a preferable blocking agent for enzyme-based assays [pg. 48, col. 1, para. 2].
Modified Zhang and Riquelme are both considered analogous to the claimed invention because they are in the same field of biosensors with aptamer-modified electrodes. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to substitute the MCH blocking agent in modified Zhang with a BSA blocking agent, as taught in Riquelme, because the substitution would provide greater compatibility with the enzyme-based assay [pg. 48, col. 1, para. 2 in Riquelme]. Furthermore, the claimed device differs from modified Zhang by the substitution of some components (MCH in modified Zhang) with other components (BSA in Riquelme) whose functions were known in the prior art. One of ordinary skill in the art could substitute one known element for another to yield predictable results (MPEP 2143(I)(B)). Furthermore, the selection of a known material, which is based upon its suitability for the intended use, is within the ambit of one of ordinary skill in the art (MPEP 2144.07). Here, Examiner notes that the streptavidin-biotin bond as taught in Smith would be interposed between the NC and the reporter RNA, not the blocking agent BSA. The limitation “thereby physically separating the reporter RNA and a Cas13a-mediated cleavage region from the nanocomposite” Regarding claim 19, the designation “the total oxidant is measured using square wave voltammetry” is deemed to be functional limitation regarding intended result in apparatus claims. MPEP 2114 (II). It does not differentiate the claimed apparatus from a prior art apparatus because the prior art apparatus teaches all the structural limitations of the claim. Ex parte Masham, 2 USPQ2d 1647 (Bd. Pat. App. & Inter. 1987).
Regarding claim 2, modified Zhang teaches the biosensor of claim 1.
The limitation “wherein the biosensor reacts with a Cas13a-crRNA-target RNA complex so that a current is reduced” is a functional recitation. Apparatus claims cover what a device is, not what a device does (MPEP 2114(II)). A functional recitation of the claimed invention must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. If the prior art structure is capable of performing the intended use, then it meets the claim. See MPEP 2114. In the instant case, modified Zhang teaches a biosensor that is configured to perform the functional limitations above (as stated in the rejection of claim 1 above, the biosensor modified Zhang uses a Cas13-compatible reRNA, such that a Cas13a-crRNA complex cleaves the reRNA upon binding with target RNA [see caption of Fig. 1, pg. 1141 in Patchsung]. When the reRNA is cleaved, methylene blue on the 3’ terminus of the reRNA dissociates from the electrode and current is reduced [see the current vs. potential graph in Scheme 1 and pg. 557, col. 1, para. 1 in Zhang], such that current is reduced when a Cas13a-crRNA-target RNA complex reacts with the biosensor).
Regarding claim 6, modified Zhang teaches the biosensor of claim 1, wherein the nanocomposite comprises the molybdenum disulfide, the graphene, and the chitosan in a volume ratio of 1:0.3 to 0.7:0.05 to 0.3 (the NC is prepared by mixing MoS2, graphene, and chitosan solutions in a 2:1:0.1 ratio [pg. 5, lines 14-18 in Kashefi Supporting Information], which is equivalent to 1:0.5:0.05 and within the claimed range).
Regarding claim 7, modified Zhang teaches the biosensor of claim 1, and further teaches wherein the reporter RNA is tagged with a redox molecule (the reporter RNA in modified Zhang has methylene blue at the 3’ terminus [pg. 559, col. 1, para. 1 in Zhang], which is a redox molecule, as evidenced by the instant claim 8).
Regarding claim 8, modified Zhang teaches the biosensor of claim 7, wherein the redox molecule is methylene blue (as stated in the rejection of claim 7 above, the redox molecule is methylene blue [pg. 559, col. 1, para. 1 in Zhang]).
Regarding claim 9, modified Zhang teaches the biosensor of claim 1, and further teaches wherein the electrode is a carbon electrode (the electrode is a screen-printed carbon electrode [pg. 4, col. 2, para. 3 in Kashefi]).
Regarding claim 24, Zhang teaches a kit for detecting a target DNA comprising a biosensor of claim 1 (as described in claim 1: a Cas12A-based electrochemical biosensing platform comprising a modified electrode, Cas12a protein, and crRNA, see Scheme 1 [pg. 560, col. 2, para. 3] in Zhang), Cas13a (see caption of Fig. 1 [pg. 1141 in Patchsung]), and a target RNA-specific crRNA (Patchsung [see Fig. 1]). Here, as described in claim 1, the biosensor of claim 1 is obvious over Zhang in view of Kashefi, Patchsung, Riquelme, and Smith. With the biosensor in modified Zhang, the target is SARS-CoV-2 RNA, and the corresponding Cas protein is Cas13a (see caption of Fig. 1 [pg. 1141 in Patchsung]). Thus, when providing a kit for detecting a target nucleic acid with the biosensor of claim 1, the kit would comprise the biosensor, Cas13a from Patchsung [see Fig. 1], and the associated target RNA-specific crRNA from Patchsung [see Fig. 1], such that the kit can be used in point-of-care applications [pg. 557, Abstract in Zhang].
Regarding claim 25, modified Zhang teaches the kit of claim 24, and further teaches wherein the target RNA is a SARS-CoV-2 RNA (as stated in the rejection of claim 24 above, the target RNA is SARS-CoV-2 RNA [see caption of Fig. 1, pg. 1141 in Patchsung]), and the crRNA is the crRNA of a S gene represented by a nucleotide sequence of SEQ ID NO: 4 (the crRNA in the Cas13a-crRNA complex is the crRNA of a S gene that matches SEQ ID NO: 4 [see Table S3, “13a_SL_S-crRNA_v1” in Patchsung Supplementary Information]).
Further, the limitation “wherein the target RNA is a SARS-CoV-2 RNA” is directed to a material or article worked upon. "Expressions relating the apparatus to contents thereof during an intended operation are of no significance in determining patentability of the apparatus claim." Ex parte Thibault, 164 USPQ 666, 667 (Bd. App. 1969). Furthermore, "[i]nclusion of material or article worked upon by a structure being claimed does not impart patentability to the claims." In re Young, 75 F.2d. 25 USPQ 69 (CCPA 1935) (as restated in In re Otto, 312 F.2d 937, 136 USPQ 458, 459 (CCPA 1963)). MPEP 2115.
Response to Arguments
Applicant’s arguments have been considered but are unpersuasive.
Applicant argues the blocking layer is not a conventional nonspecific adsorption-preventing layer (Response, p. 9, section (3)). However, Applicant’s amendments in claim 1 introduces new matter that is not disclosed in the specification. Instead, the specification discloses the gap between the immobilized SAs by BSA was filled (PGpub ¶137).
Applicant’s arguments against Riquelme (p. 10, section (3)(B)) is unpersuasive. First, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986). Second, the claims under examination are apparatus claims, and a claim containing a "recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus" if the prior art apparatus teaches all the structural limitations of the claim. Ex parte Masham, 2 USPQ2d 1647 (Bd. Pat. App. & Inter. 1987).
Applicant argues biotin-streptavidin immobilization is not a simple substitute for thiol-gold binding (p. 11, section (4)). This argument is unpersuasive because biotin-strept(avidin) systems are known in the prior art for immobilization, and provide several advantages for a large number of molecules without interfering with their function (Smith, [Abstract]). Thus, it would be obvious to one of ordinary skill in the art to use a known technique in the prior art to obtain the predictable results.
Applicant argues the present invention achieves an extremely low detection limit without any nucleic acid amplification in section (5), which is not naturally arises from a combination of known elements (p. 11-12). Examiner suggests Applicant incorporating any additional elements beyond the combination of these known elements into the claims to show how these additional elements result in the alleged unpredictable technical effect.
Conclusion
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 extension fee 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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to CAITLYN M SUN whose telephone number is (571)272-6788. The examiner can normally be reached M-F: 8:30am - 5:30pm.
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/C. SUN/Primary Examiner, Art Unit 1795
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