A double bipolar electrode electrochemiluminescence device for rapid visual detection of organophosphorus pesticides

Abstract

A visual electrochemiluminescence (ECL) sensing platform based on double bipolar electrode (D-BPE) for the detection of organophosphorus pesticides (OPPs) was reported in this work. The D-BPE consists of a cathode and two anodes. (where the cathode was filled with 1 × PBS. The anode 1 was filled with luminol-H2O2 solution and serves as the ECL signal reporting cell. Anode 2 serves as the OPPs detection sensing cell). In this method, according to the electroneutrality principle of BPE, the ECL signal at anode 1 was enhanced due to the enzymatic reaction occurring at anode 2 that promoted electron transfer. When OPPs was added to the sensing cell at anode 2, the enzymatic reaction was inhibited, resulted in weakening of the ECL signal at anode 1. In this strategy, the detection limit of malathion (template for OPPs) down to 0.5 ng mL−1 was showed. In this report, the non-visualized Faraday current signals was converted into a more intuitive visual perception. This makes the detection of OPPs fast and easy. On the other hand, the two anodes of the D-BPE was physically isolated from each other, thus avoided mutual interference between the target detection and the electrochemiluminescent reagents. In addition, the surface of the D-BPE does not need to be modified, which greatly reduced the overall experiment time to only 0.5 h. This D-BPE device combines the sensitivity of electrochemistry with the simplicity and intuitiveness of optical readout and can be widely used for the rapid detection of OPPs.