Ultrasensitive molecularly imprinted electrochemiluminescence sensor based on enzyme-encapsulated liposome-linked signal amplification for trace analysis

Abstract

A molecularly imprinted polymer (MIP)-electrochemiluminescence (ECL) sensor was prepared and an ultrasensitive strategy was proposed for detecting an ultra-trace amount of ethiprole based on the enzymatic signal amplification of glucose oxidase (GOD). The ethiprole molecule on the MIP was marked with GOD-encapsulated liposomes via light-triggered click reaction after elution and readsorption. Many GOD particles were released from the liposomes and catalyzed the reaction to produce a large amount of H2O2 in the presence of glucose, which considerably enhanced the ECL intensity of luminol. Therefore, the sensitivity for ethiprole determination was promoted remarkably. The ECL signal of the sensor was linearly related to the logarithm of ethiprole concentration from 5.00 × 10−16 M to 5.00 × 10−11 M, and the detection limit was 1.00 × 10−16 M, which was the lowest of all the analytical methods used in ethiprole determination. Ethiprole in samples was determined directly without the tedious and complicated sample treatment procedures, such as separation and enrichment. The click chemistry labeling method using liposomes simplified the operation steps of the MIP-ECL sensor in ethiprole determination.