Ochratoxin A (OTA) with high toxicity represents a serious threat to the agriculture and food chain, consequently to human health. Herein, a simple electrochemiluminescence (ECL) biosensor was constructed for ultrasensitive detection of OTA based on mercaptopropionic acid templated Au nanoclusters (Au NCs) as intensive signal probe and a non-enzymatic 2D DNA walking machine as the effective amplification strategy. Specifically, the target related bipedal DNA walker efficiently moved along 2D DNA tracks through toehold-mediated DNA strand displacement, which triggered abundant signal probes for combining to the DNA tracks. Moreover, the Au NCs could exhibit strong ECL emission due to fast electron transfer from massive Au-S electronic pathways under the electrochemical excitation. Thus, the biosensor possessed significant ECL response for achieving ultrasensitive detection toward OTA with low detection limit of 3.19 fg/mL. Impressively, the sensing platform was also applied to detect OTA from edible oils, exhibiting great application potential in food analysis.

具有高毒性的赭曲霉毒素 A (OTA) 对农业和食物链构成严重威胁，进而对人类健康构成威胁。在此，构建了一种简单的电化学发光 (ECL) 生物传感器，用于基于巯基丙酸模板化金纳米团簇 (Au NCs) 作为强信号探针和非酶促 2D DNA 行走机作为有效扩增策略的 OTA 超灵敏检测。具体来说，目标相关的双足 DNA 步行者通过立足点介导的 DNA 链位移有效地沿着 2D DNA 轨道移动，这触发了丰富的信号探针以结合到 DNA 轨道。此外，由于在电化学激发下大量 Au-S 电子通路的快速电子转移，Au NCs 可以表现出强烈的 ECL 发射。因此，该生物传感器具有显着的 ECL 响应，可实现对 OTA 的超灵敏检测，检测限低至 3.19 fg/mL。令人印象深刻的是，该传感平台还被应用于检测食用油中的OTA，在食品分析中展现出巨大的应用潜力。