Preparation of ratiometric electrochemical sensor based on molecular imprinting copolymer and β-‍‍cyclodextrin recognition for the reliable detection of dinotefuran.

Dinotefuran (DNF) residue in foods is harmful to human health, hence, it is significant to detect it. Herein, a composite of β-‍‍cyclodextrin/activated mung bean-derived carbon (β-CD/AMBC-3) was prepared and used to modify GCE. Then a DNF imprinted copolymer (MIP) film of thionine and catechol was electrodeposited. The AMBC-‍3 had plentiful pores, excellent conductivity, and high catalytic activity, beneficial for β-CD immobilization and signal amplification; the MIP and β-CD could cooperate to improve recognition capability. In addition, the poly(thionine) could act as an internal-reference probe for ratiometric detection, calibrating the effects of condition fluctuation during detection. Thus, the resulted sensor displayed high reproducibility, selectivity, and sensitivity. It showed linear response to DNF over the range of 0.05 ‍μM-10 μM, with a detection limit of 0.016 ‍μM (S/N = 3) and sensitivity of 550.6 μA mM cm. Its practicability was validated by determining DNF in real samples, with recoveries of 92.0 %-102 %.