Simultaneous quantification of seven multi-class organic molecules by single-shot dilution differential pulse voltammetric calibration

Multi-electrode platform for selective electrochemical sensing: 3D-printed insulating plastic is turned into a five-electrodes chip

We report a method to turn a 3D-printed plastic piece into a five-electrodes chip for multiple analytes detection. A chip containing Pd, Ni, and Ru working electrodes is used to sense hydroquinone, acetaminophen, salicylic acid, and hydroxychloroquine at once. The analysis is sequentially achieved simply by changing the proper electrode connection, without changing mobile parts, neither adding reactants, nor electrolytes. This strategy is an alternative for low-cost selective electrochemical detection.

Novel electrochemical sensor modified with molecularly imprinted polymers for determination of enrofloxacin in marine environment

Molecularly imprinted polymers were synthesized by gel-sol method with multi-walled carbon nanotubes as support and enrofloxacin as a template and further modified on the surface of glassy carbon electrode to construct a molecularly imprinted electrochemical sensor. The performance of the imprinted electrochemical sensor was thoroughly investigated by using cyclic voltammetry and differential pulse voltammetry. The influence of imprinted polymers amount, electrolyte pH, and incubation time on the sensor performance was investigated for the detection of enrofloxacin. Under the optimal experimental conditions in a three-electrode system with the modified electrode as the working electrode the differential pulse voltammetry response current of the sensor had a good linear relationship at 0.2 V (vs. saturated calomel reference electrode) with the enrofloxacin concentration within 2.8 pM-28 μM and the limit of detection of the method was 0.9 pM. The competitive interference experiment showed that the imprinted electrochemical sensor could selectively recognize enrofloxacin. The method was applied to analyze spiked natural seawater, fish, and shrimp samples. The recovery was 96.4%-102%, and RSD was less than 4.3% (n = 3), indicating that the proposed imprinted electrochemical sensor was suitable for the determination of trace enrofloxacin in marine environment samples.