Rapid and effective analysis of foodborne bacteria is crucial for preventing and controlling bacterial infections. Here, we present the synthesis of a self-reporting molecularly imprinted polymer (MIP) as an inner reference probe (IR), and the in-situ growth of metal-organic frameworks on transition metal carbon nitrides (MOF/Ti3C2TX-MXene) as a signaling nanoprobe (SP). These advancements are then applied in a ratiometric electrochemical bioassay for Staphylococcus aureus (S. aureus) using a hybrid recognition mechanism. When S. aureus is present, the aptamer-integrated MIP (MIP@Apt) efficiently captures it, followed by binding with SP to form a sandwich structure. This leads to decreased current response of IR (IIR) and increased current intensity of SP (Isp), enabling quantification through utilization of the ISP to IIR ratio. The biosensor shows a wide detection range (10-108 CFU mL-1) and low detection limit of 1.2 CFU mL-1. Its feasibility for testing complex samples indicates the potential application in food analysis.
Keywords: Foodborne bacteria; Metal-organic frameworks; Molecularly imprinted polymer; Ratiometric biosensor.
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