A novel aptasensor based on Fe₃O₄/Au/g-C₃N₄ for sensitive detection of sulfameter in food matrices

A novel fluorescence aptasensor based on Fe3O4/Au/g-C3N4 was designed and manufactured for sensitive detection of sulfameter in animal-derived foods. The specific aptamers for sulfameter were obtained using magnetic bead-SELEX and the aptamers were further optimized by truncating the originally obtained sequence to a 13 nt sequence (5'-CCGACTGGCTCGG-3') with a unique stem-loop structure and high affinity (K-d = 83.65 nM). Fe3O4/Au/g-C3N4 was reported for the first time and used in the development of aptasensor. The limit of detection of the aptasensor for sulfameter was shown to be 1.57 ng/mL (S/N = 3). The aptasensor was further used to analyze samples spiked with sulfameter, and recoveries were determined to be from 92.42% to 107.22% with coefficients of variation below 15%. In addition, excellent correlations (R-2 > 0.9304) were observed between the results obtained from the new aptasensor and those from HPLC in the same spiked samples. The experimental date demonstrated that the novel aptasensor is a promising candidate for rapid and accurate detection of sulfameter in food matrices.