Rapid Visual Screening of OTA Based on Multicolor Electrochemiluminescence

A multicolor electrochemiluminescence (ECL) apparatus based on a closed bipolar electrode (BPE) system was proposed for the visual testing of Ochratoxin A (OTA). Since the oxidation potentials of the accompanying luminophores ([Ru(bpy)(3)](2+) and [Ir(ppy)(3)]) are different, a bidirectional color change from dark orange to yellow to forest green can be discovered at the anode of BPE by adjusting the current of the BPE. The presence of OTA was reflected by target-induced elimination of the Fc-aptamer from the cathode pole, leading to a reduction in the current of the BPE and a color change on the anode electrode. A low detection limit of 10 ng mL(-1) of OTA could be identified with naked eyes. Combining sensitivity of electrochemistry with the intuitiveness of optical reading, the device holds great potential in the rapid food safety testing.

Automated summary

A multicolor electrochemiluminescence (ECL) apparatus based on a closed bipolar electrode (BPE) system was proposed for the visual testing of Ochratoxin A (OTA). The presence of OTA was reflected by target-induced elimination of the Fc-aptamer from the cathode pole, leading to a reduction in the current of the BPE and a color change on the anode electrode. The device holds great potential in the rapid food safety testing.