Development of electrochemical aptasensor based on gold nanoparticles and electrospun carbon nanofibers for the detection of aflatoxin M1 in milk

An electrochemical aptasensor was developed based on electrospun carbon nanofiber (ECNF) mat for detection of aflatoxin M1 (AFM1) in the milk samples. The ECNF mat was firstly produced by electrospinning and heat treatment method utilized directly as a novel substrate electrode. This electrode was then modified by electrodeposition of gold nanoparticles (AuNPs) and immobilization of a thiol-modified single stranded DNA (ss-HSDNA), respectively. The structure and morphology of prepared ECNF mat and AuNPs/ECNF mat electrode were characterized by means of Raman spectroscopy and scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS). The characterization results indicated that the gold nanopartciles were uniformly electrodeposited on ECNF mat electrode. To analysis each step of the aptasensor development, cyclic voltammetry (CV) experiments were carried out in the [Fe(CN) 6 ] −3/−4 solution. The biosensor exhibited a low detection limit (0.6 pg/mL), a wide and useful linear range (1-100 pg/mL), high sensitivity, excellent stability and reproducibility as well as good recovery. Moreover, the results obtained in this research were comparable to those obtained using the HPLC. Thus, good electrochemical performance and simple preparation procedure of the ss-HSDNA/AuNPs/ECNF mat electrode can provide promising potential for the detection of AFM1 in milk samples.