Investigation of the effective parameters on aptamer-based electrochemical biosensors for the detection of fumonisin B1 in maize flour

This study examined the effective parameters on fabrication of an aptasensor to detect fumonisin B1 (FB1) in maize flour. For this purpose, gold nanoparticles (AuNPs) was firstly electrodeposited onto screen printed carbon electrode (SPCE). Then, a thiol-modified single stranded DNA (ss-HSDNA) was immobilized on the AuNPs/SPCE electrode. By applying the cyclic voltammetry (CV) technique, the effects of HAuCl4 and ss-HSDNA concentrations in the electrolyte, incubation time of aptamer and FB1, pH and temperature of the electrolyte on the peak current response were investigated. The findings indicated that the optimal concentration of HAuCl4 was 5 mM. The peak current of CV decreased as the concentration of ss-HSDNA increased and the optimum ss-HSDNA concentration was chosen at 5 µM. In addition, the CV peak currents decreased with increasing incubation time of aptamer or FB1. The peak currents of CV first decreased and then increased as the electrolyte's temperature increased. The electrolyte's pH also showed this trend. Base on the results, this aptasensor could be a promising tool for FB1 detection in maize flour.