|
چکیده
|
Here, a highly sensitive electrochemical aptasensor based on a novel signal amplification strategy for the determination of bisphenol A (BPA) was developed. Construction of the aptasensor began with the deposition of highly dispersed platinum nanoparticles (PtNPs)/acid-oxidized carbon nanotubes (CNTs eCOOH) functionalized with polyethyleneimine (PEI) at the surface of glassy carbon (PtNPs/PEI/CNTs eCOOH/GC) electrode. After immobilizing the amine-capped capture probe (ssDNA1) through the covalent amide bonds formed by the carboxyl groups on the nanotubes and the amino groups on the oligonucleotides, we employed a designed complementary BPAeaptamer (ssDNA2) as a detection probe to hybridize with the ssDNA1. By adding BPA as a target, the aptamer specifically bound to BPA and its end folded into a BPA-binding junction. Because of steric/conformational restrictions caused by aptamereBPA complex formation at the surface of modified electrode, the interfacial electron transfer of [Fe(CN)6]3/4 as a probe was blocked. Sensitive quantitative detection of BPA was carried out by monitoring the decrease of differential pulse voltammetric responses of [Fe(CN)6]3/4 peak current with increasing BPA concentrations. The newly developed aptasensor embraced a number of attractive features such as ease of fabrication, low detection limit, excellent selectivity, good stability and a wide linear range with respect to BPA.
|