Electrochemical sensor based on corncob biochar layer supported chitosan-MIPs for determination of dibutyl phthalate (DBP)

Abstract

The new corncob biochar layer supported chitosan-based molecular imprinting electrochemical sensor was successfully prepared. Compared with the bare electrode, the new sensor had a good imprinted effect. • A MIP-DBP-CTS/F-CC 3 /GCE novel senor was prepared by molecular imprinting. • The sensor combined the advantages of F-CC 3 and MIP achieved high sensitivity and selective detection of DBP. • The sensor for DBP exhibits a low detection limit of 2.6 nM. • The designed sensor was successfully applied to DBP detection in rice wine purchased in the market. A highly selective and sensitive electrochemical sensor (MIP-DBP-CTS/F-CC 3 /GCE) for dibutyl phthalate (DBP) detection was prepared. Firstly the functional corncob biochar (F-CC 3 ) was cast on a glassy carbon electrode (GCE) to form F-CC 3 film. Then, the pretreated GCEs were further modified by molecularly imprinted polymers synthesized with CTS as functional monomer, DBP as the template molecule, glutaraldehyde as the crosslinking agent. The MIP-DBP-CTS/F-CC 3 /GCE sensor was characterized by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). The results showed that the utilization of conductive F-CC 3 as interlayer spacers efficiently inhibited the aggregation of CTS and formed a well-defined porous structure, as a result of increasing the effective surface area, an enhancement of the electrical conductivity was observed. This sensor takes advantages of molecularly imprinted technique and F-CC 3 biomass materials to achieve high selectivity and high sensitivity for the determination of DBP. The as-prepared molecular imprinting sensor, under the optimized conditions, presented a good linear relationship ( R 2 = 0.9929) between the response current Δ I and the DBP concentration ranging of 0 ~ 1.8 μM with a limit of detection (LOD) of 0.0026 μM. Besides, this newly developed sensor was utilized for the detection of DBP in rice wine purchased in the market with satisfactory results.