Shared hairpin structure electrochemical aptasensor based on ZrO2@Ni/Co-MOFs@AuNPs for dual-target detection of Cd2+ and S.aureus

Heavy metals and foodborne pathogens have become key pollutants that harm aquatic products, seriously endangering food safety and human health. Therefore, in this study, a ratiometric electrochemical aptamer sensor with a novel signal amplification strategy was constructed using ZrO2 as the substrate and Ni/Co-MOFs@AuNPs cubic nanomaterials to increase the specific surface area to simultaneously detect Cd2+ and S.aureus. The shared hairpin complementary chains modified with ferropene (Fc) could simultaneously bind to the Cd2+ and S.aureus aptamers modified with methylene blue (MB) and anthrquinone-2-carboxylic acid (AQ). The ratios of MB and AQ to Fc were used to realize the qualitative and quantitative detection of Cd2+ and S.aureus. Under the optimal conditions, the electrochemical aptamer sensor for Cd2+ and S.aureus was in the range of 1.00 × 10−2-1.00 × 104 ng/L and 1.00 × 101-1.00 × 107 CFU/mL, and the lowest detection limit was 1.91 × 10−4 ng/L and 1.37 CFU/mL, respectively. The aptasensor constructed in this paper can realize the simultaneous detection of Cd2+ and S.aureus in scallop and fish, providing a new detection method for the simultaneous detection of a variety of aquatic products pollutants.