Design of a new electrochemical aptasensor based on screen printed carbon electrode modified with gold nanoparticles for the detection of fumonisin B1 in maize flour

Abstract

A new aptasensor for the detection of fumonisin B1 (FB1) in the maize samples was developed based on DNA- aptamer recognition and electrochemical technique. A thiol-modified single stranded DNA (ss-HSDNA) was immobilized on screen printed carbon electrode (SPCE) electrodeposited by gold nanoparticles (AuNPs). The morphology and structure of SPCE and AuNPs/SPCE were evaluated via scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS). The SEM results demonstrated that the SPCE had a flat sheet-like structure and the AuNPs were homogeneously electrodeposited on the SPCE. Cyclic voltammetry (CV) experiments in the [Fe(CN)6]-3/-4 solution were conducted to investigate each step of electrode modification as well as aptasensor performance. Aptamer-FB1 interaction prevented the electron transfer permitting the determination of FB1 in the range of 0.5-500 ng/L with a low detection limit (0.2 ng/mL). The designed aptasensor was also showed high selectivity, acceptable repeatability and reproducibility, good long-term stability and excellent recovery. Furthermore, there was a strong correlation between the findings achieved via the designed aptasensor and HPLC. Therefore, a simple construction process and fine electrochemical performance of the proposed aptasensor have a great potential for the detection of FB1 in maize samples.