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Updated: Jun 27, 2026
Fabrication of Electrochemical-DNA Biosensors for the Reagentless Detection of Nucleic Acids, Proteins and Small Molecules
Published on: June 1, 2011
Electrochemical DNA biosensor based on silver nanoparticles/poly(3-(3-pyridyl) acrylic acid)/carbon nanotubes
Yuzhong Zhang1, Keying Zhang, Haiyan Ma
1College of Chemistry and Materials Science, Anhui Key Laboratory of Chem-Biosensing, Anhui Normal University, Wuhu, People's Republic of China. zhyz65@ahnu.edu.cn
Abstract:
In this work, we present an electrochemical DNA sensor based on silver nanoparticles/poly(trans-3-(3-pyridyl) acrylic acid) (PPAA)/multiwalled carbon nanotubes with carboxyl groups (MWCNTs-COOH) modified glassy carbon electrode (GCE). The polymer film was electropolymerized onto MWCNTs-COOH modified electrode by cyclic voltammetry (CV), and then silver nanoparticles were electrodeposited on the surface of PPAA/MWCNTs-COOH composite film. Thiol group end single-stranded DNA (HS-ssDNA) probe was easily covalently linked onto the surface of silver nanoparticles through a 5' thiol linker. The DNA hybridization events were monitored based on the signal of the intercalated adriamycin by differential pulse voltammetry (DPV). Based on the response of adriamycin, only the complementary oligonucleotides gave an obvious current signal compared with the three-base mismatched and noncomplementary oligonucleotides. Under the optimal conditions, the increase of reduction peak current of adriamycin was linear with the logarithm of the concentration of the complementary oligonucleotides from 9.0 x 10(-12) to 9.0 x 10(-9) M with a detection limit of 3.2 x 10(-12) M. In addition, this DNA sensor exhibited an excellent reproducibility and stability during DNA hybridization assay.
