title: A label-free and cascaded dual-signaling amplified electrochemical aptasensing platform for sensitive prion assay.
abstract: Prion proteins, as an important biomarker of prion disease, are responsible for the transmissible spongiform encephalopathies (a group of fatal neurodegenerative diseases). Hence, the sensitive detection of prion protein is very essential for biological studies and medical diagnostics. In this paper, a novel label-free and cascaded dual-signaling amplified electrochemical strategy was developed for sensitive and selective analysis of cellular prion protein (PrP(C)). The recognition elements included double-stranded DNA consisted of PrP(C)-binding aptamer (DNA1) and its partially complementary DNA (DNA2), and ordered mesoporous carbon probe (OMCP) fabricated by sealing the electroactive ferrocenecarboxylic acid (Fc) into its inner pores and then using single-stranded DNA (DNA3) as the gatekeeper. In the presence of PrP(C), DNA1 could bind the target protein and free DNA2. More importantly, DNA2 could hybridize with DNA3 to form a rigid duplex DNA and thus triggered the exonuclease III (Exo III) cleavage process to realize the DNA2 recycling, accompanied by opening more biogates and releasing more Fc. The released Fc could be further used as a competitive guest of β-cyclodextrin (β-CD) to displace the Rhodamine B (RhB) on the electrode. As a result, an amplified oxidation peak current of Fc (RhB) increased (decreased) with the increase of PrP(C) concentration. When "ΔI=ΔIFc+|ΔIRhB|" (ΔIFc and ΔIRhB were the change values of the oxidation peak currents of Fc and RhB, respectively.) was used as the response signal for quantitative determination of PrP(C), the detection limit was 7.6fM (3σ), which was much lower than that of the most reported methods for PrP(C) assay. This strategy provided a simple and sensitive approach for the detection of PrP(C) and has a great potential for bioanalysis, disease diagnostics, and clinical biomedicine applications.
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China.
authors.forename: Peng
authors.initials: P
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China. Electronic address: mickyxie@hnu.edu.cn.
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China.
authors.forename: Erhu
authors.initials: E
authors.lastname: Xiong
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China.
authors.forename: Jiawan
authors.initials: J
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Li
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China. Electronic address: chenjinhua@hnu.edu.cn.
authors.forename: Jinhua
authors.initials: J
authors.lastname: Chen
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002244:Carbon / Q000737:chemistry; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D005090:Exodeoxyribonucleases / Q000737:chemistry; D005296:Ferrous Compounds / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D000075163:Metallocenes; D016062:Porosity; D018621:PrPC Proteins / Q000032:analysis / Q000097:blood*; D012235:Rhodamines / Q000737:chemistry; D047392:beta-Cyclodextrins / Q000737:chemistry
chemical_list: D052157:Aptamers, Nucleotide; D005296:Ferrous Compounds; D000075163:Metallocenes; D018621:PrPC Proteins; D012235:Rhodamines; D047392:beta-Cyclodextrins; C032949:ferrocenecarboxylic acid; D002244:Carbon; D005090:Exodeoxyribonucleases; C020133:exodeoxyribonuclease III; C029773:rhodamine B
keywords: Aptasensor; Exonuclease III; Host-guest interaction; Ordered mesoporous carbon; Prion protein