DNA template-mediated click chemistry-based portable signal-on sensor for ochratoxin A detection

A novel signal-on portable sensing system has been developed for OTA detection using personal glucose meter (PGM) as signal transducer. In the study, we explore the potential of using a short dsDNA as template to trigger the "click" ligation of two DNA strands, further improve the stability of DNA strand on the magnetic beads (MBs) surface, and thereby reduce the background signal. Compared with no "click" ligation, the background signal decreases 7.5 times. Both the sensitivity and selectivity are greatly promoted. A high sensitivity with OTA detection down to 72 pg/mL is achieved, which is comparable with several existing detectors, such as fluorescence-based detectors and electrochemical detectors. The feasibility of the strategy in real samples is well verified and evaluated by detecting OTA in feed samples, indicating the potential application in the food safety field.