Electrochemiluminescence Detection of Escherichia coli 0157:H7 Based on a Novel Polydopamine Surface Imprinted Polymer Biosensor

In this paper, a facilely prepared electrochemiluminescence (ECL) biosensor was developed for Eseherichia coli 0157:H7 quantitative detection based on a polydopamine (PDA) surface imprinted polymer (SIP) and nitrogen-doped graphene quantum dots (N-GQDs). N-GQDs with a high quantum yield of 43.2% were synthesized. The uniform PDA SIP film for E. coli 0157:H7 was established successfully with a facile route. The dopamine and target bacteria were electropolymerized directly on the electrode. After removal of the E. coli 0157:H7 template, the established PDA SIP can selectively recognize E. coli 0157:H7. Accordingly, E. coli 0157:H7 polyclonal antibody (pAb) was labeled with N-GQDs. The bioconjugation of SIP E. coli 01S7:H7/pAb-N-GQDs can generate intensive ECL irradiation with K(2)S(2)0(8). As a result, E. coli 0157:H7 was detected with the ECL sensing system. Under optimal conditions, the linear relationships between the ECL intensity and E. coli 0157:H7 concentration were obtained from 101 colony-forming units (CFU) mL(-1) to 10(7) CFU mL(-1), with a limit of detection of 8 CFU mL(-1). The biosensor based on this SIP film was applied in water sample detection successfully. The N-GQD-based ECL analytical method for E. coli 0157:H7 was reported for the first time. The sensing system had high selectivity to the target analyte, provided new opportunities for use, and increased the rate of disease diagnosis and treatment and the prevention of pathogens.