A label-free electrochemical aptasensor for sensitive myoglobin detection in meat

A novel electrode fabrication method was designed to establish a highly sensitive label-free electrochemical aptasensor for myoglobin (Mb) detection. The aptasensor was successfully built by grafting Mb-binding-aptamer (MBA) onto the surface of Au nanoparticles/arginine-glycine-aspartic/carboxylated graphene/glassy carbon electrode (Au/RGD/GR-COOH/GCE). Raman spectroscopy was used to demonstrate the process of successful electrode fabrication. Circular dichroism (CD) spectroscopy was performed to estimate the change of secondary structure of MBA in different modified electrodes. The scan rate, pH, the binding time of MBA, adsorption time and adsorption temperature of Mb were optimized by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The DPV was also employed to recognize Mb and excellent performance was possessed with a detection limit of 26.3   ng   mL −1 (S/N   =   3) and a linear range from 0.0001 to 0.2   g   L −1 . Moreover, the fabricated aptasensor also exhibited good reproducibility, stability and anti-interference capacity. The aptasensor was applied to biochemical assays and the results were satisfactory. The detection method was successfully built, which could provide a promising platform for evaluation of meat quality.