Electrochemical Detection of Aflatoxin B1; an Aptasensor prepared using graphene oxide and gold nanowires

An electrochemical aptasensor was developed for detection of aflatoxin B1 using nanocomposite of graphene oxide and gold nanowires. The aptasensor mechanism was based on difference in differential pulse voltammetry peak current upon detachment of aptamer from electrode surface when the toxin is present. The working electrode modifications was confirmed using field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and electrochemical methods cyclic voltammetry and electrochemical impedance spectroscopy. Limit of detection was 1.4 pM and linear range was 5.0- 750.0 pM with good reproducibility of the results. The specificity test of the aptasensor was successfully confirmed that the aptasensor is specific towards aflatoxin B1 comparing to blank solution and non-specific molecules. The simulated real sample environment tested in pistachio samples alongside with experiments and comparison with HPLC method confirmed the aptasensor capability to work in future real food assays.