A novel Bi₂S₃ QD-based DPV/ECL synchronous dual-mode molecularly imprinted sensor for enrofloxacin detection in eggs

Herein, a novel electrochemiluminescence (ECL) and differential pulse voltammetry (DPV) dual-mode-based molecularly imprinted (MIP) sensor had been established for the detection of enrofloxacin (ENR) in eggs. Firstly, bismuth sulfide quantum dots (Bi₂S₃ QDs) as ECL luminophore were synthesized. Furthermore, a MIP film with ionic liquid (ILs), Bi₂S₃ QDs, and ENR was prepared via the electrochemical polymerization procedure on the electrode. As ENR was identified and captured by the imprinted cavities, the electron transfer pathway was blocked on the electrochemical interface, resulting in the decrease of both DPV signals and ECL signals. As a novel synchronous dual-mode sensing strategy, a pulsed voltage was applied to produce both the DPV signal and ECL signal simultaneously. The ECL and DPV response showed the good linear relationships with the concentration of ENR with the ranges of 0.5 Nm-25 μM and 5 nM-25 μΜ and the detection limits of 0.13 nM and 1.59 nM, respectively.