A molecularly imprinted sensor with enzymatic enhancement of electrochemiluminescence of quantum dots for ultratrace clopyralid determination

Abstract

A new molecularly imprinted polymer electrochemiluminescence (ECL) sensor was developed for the detection of clopyralid (CPD) based on enzyme-biocatalyzed amplification. CdTe quantum dots were immobilized on the surface of an electrode by reaction with p-aminothiophenol preadsorbed on the electrode. Then a molecularly imprinted film was formed by electrochemical polymerization of o-phenylenediamine in the presence of CPD on the CdTe-modified gold electrode. During the analytical cycle, horseradish peroxidase (HRP)-labeled CPD was replaced by CPD in the sample. The amount of HRP on the molecularly imprinted polymer electrode decreased, and then less HO was catalytically decomposed. Subsequently, the ECL intensity of the CdTe-HO system was enhanced. There was a good linear relationship between ECL intensity and the concentration of CPD in the range from 2.0 × 10 to 2.5 × 10 mol/L and in the range from 2.5 × 10 to 3.5 × 10 mol/L. The detection limit was 4.1 × 10 mol/L. The sensor was applied to determine CPD in vegetable samples. Graphical abstract A molecularly imprinted electrochemiluminescence sensor was fabricated for ultratrace clopyralid determination. The sensitivity was significantly improved with the enhancement of the ECL intensity of quantum dot via the enzymatic reaction of HRP.

Self-assembled Imprinted Polymer Film-Based Sensor System for Spermidine on Screen Printed Electrodes

“…The saturated adsorption time was referenced with the adsorption equilibrium time (360 s), and the current changed was detected by DPV scanning in the range of −0.8~1.0 V. Plot the standard curve with the response values and spermidine concentration. The detection limit was determined by formula: DL = 3δb/K, where δb is the standard deviation (SD) of blank parallel determination (10 times) and the calculated values, and K is the slope of the standard curve [36].…”

“…Molecularly imprinted polymers can adsorb the target substance by geometric and structural matching principles [36]. Tyramine and histamine, similar in shapes and groups of spermine, were selected as interfering components.…”

Electrochemiluminescence of Carbon‐based Quantum Dots: Synthesis, Mechanism and Application in Heavy Metal Ions Detection

“…At present, a variety of ECL emitters such as transition metal complexes, organic molecules, metal nanoclusters and quantum dots have been developed and applied [6]. Among these ECL luminophores, quantum dots have aroused broad attention due to their unique features, including easy labelling and excellent ECL activities [7]. However, semiconductor quantum dots, including cadmium‐telluride (CdTe) and cadmium‐selenium (CdSe) quantum dots, have limited applicability because of their environmental toxicity, complex preparation, and poor biocompatibility [8].…”