Effect of processing variables on the performance of electrochemical aptasensor for determination of aflatoxin M1

A novel aptasensor based on electrospun carbon nanofiber (ECNF) mat modified with gold nanoparticles (AuNPs) and aptamer was fabricated to detect aflatoxin M1 (AFM1) in the milk. The electrospinning and heat treatment technique were firstly used to construct the ECNF mat electrode. Then, this platform was electrodeposited by AuNPs and immobilized with a thiol-modified single stranded DNA (ss-HSDNA). The effect of processing parameters such as concentration of HAuCl4 and ss-HSDNA in the electrolyte, incubation time of aptamer and AFM1, pH and temperature of the electrolyte on the performance of aptasensor was investigated using cyclic voltammetry (CV) experiments in the [Fe(CN)6]-3/-4 solution. The results showed that the optimum concentration of HAuCl4 in the electrolyte was 4mM. An increment in ss-HSDNA aptamer of electrolyte led to improvement of the electrochemical current response. Furthermore, the peak currents of CV enhanced with increasing incubation time of aptamer or AFM1. By increasing temperature of the electrolyte, the CV peak currents increased and then decreased. This trend was also observed in pH of electrolyte.