Detecting DNA-DNA hybridization at 3-mercaptopropionic acid self-assembled on tin-doped indium oxide film with electrochemical measurement

Abstract

Self-assembled monolayers (SAM) of 3-mercaptopropionic acid (MPA) were applied on tin-doped indium oxide (ITO) surfaces and used as a working electrode for sensing DNA hybridization. The concentration of probe single stranded DNA (ssDNA), complemented with target DNA, was optimized for the highest yield immobilization on MPA/ITO platform. The ssDNA/MPA/ITO was allowed to hybridize to target DNA prepared from PCR amplification that first tested by the synthesized complementary sequences. Both cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were employed for investigating probe ssDNA immobilization and target DNA hybridization. For fast and low concentration detecting purposes, methylene blue (MB) coupled with differential pulse voltammetry (DPV) was used for detecting the target DNA hybridization events.