期刊
ANALYTICA CHIMICA ACTA
卷 1044, 期 -, 页码 102-109出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/j.aca.2018.07.045
关键词
Paper-based electrochemical DNA biosensor; Electrochemical impedance spectroscopy; Mycobacterium tuberculosis; acpcPNA
资金
- Thailand Graduate Institute of Science and Technology (TGIST) [01-55-014]
- Thailand Research Fund [DPG5780002, RTA6080002]
- Ratchadaphisaksomphot Endowment Fund of Chulalongkorn University
- Colorado State University through the Catalysts for Innovative Partnerships program
A label-free electrochemical DNA sensor based on pyrrolidinyl peptide nucleic acid (acpcPNA)-immobilized on a paper-based analytical device (PAD) was developed. Unlike previous PNA-based electrochemical PAD (ePAD) sensors where the capture element was placed directly on the electrode, acpcPNA was covalently immobilized onto partially oxidized cellulose paper allowing regeneration by simple PAD replacement. As an example application, a sensor probe was designed for Mycobacterium tuberculosis (MTB) detection. The ePAD DNA sensor was used to determine a synthetic 15-base oligonucleotide of MTB by measuring the fractional change in the charge transfer resistance (R-ct) obtained from electrochemical impedance spectroscopy (EIS). The R-ct of [Fe(CN)(6)](3-/4-) before and after hybridization with the target DNA could be clearly distinguished. Cyclic voltammetry (CV) was used to verify the EIS results, and showed an increase in peak potential splitting in a similar stepwise manner for each immobilization step. Under optimal conditions, a linear calibration curve in the range of 2-200 nM and the limit of detection 1.24 nM were measured. The acpcPNA probe exhibited very high selectivity for complementary oligonucleotides over single-base-mismatch, two-base-mismatch and non-complementary DNA targets due to the conformationally constrained structure of the acpcPNA. Moreover, the ePAD DNA sensor platform was successfully applied to detect PCR-amplified MTB DNA extracted from clinical samples. The proposed paper-based electrochemical DNA sensor has potential to be an alternative device for low-cost, simple, label-free, sensitive and selective DNA sensor. (C) 2018 Elsevier B.V. All rights reserved.
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