AgTCNQ nanoshuttle as a novel organic electrochemiluminescence emitter for ultrasensitive label-free detection of aflatoxin B1

The search for novel efficient organic electrochemiluminescence (ECL) emitters is still an active and ongoing topic. Herein, a well-known metal–organic semiconducting charge transfer structure, AgTCNQ, is identified as a promising organic ECL emitter. AgTCNQ nanoshuttles were synthesized and used for the first time to demonstrate robust cathodic ECL emission with K2S2O8 as a coreactant. The ECL mechanism of the AgTCNQ nanoshuttles was investigated, revealing a red-shifted ECL emission attributed to surface states. Leveraging the strong and stable ECL of AgTCNQ nanoshuttles, a label-free ECL immunosensor was developed for the sensitive detection of aflatoxin B1 (AFB1) in Chinese herbal medicine. The immunosensor demonstrated excellent analytical performance with a linear range of 3.16 × 10−15 to 3.16 × 10−13 g/mL, a low detection limit of 9.33 × 10−16 g/mL, and good stability and reproducibility. Selectivity tests and detection in Chinese herbal medicines validate the specificity and feasibility of the proposed ECL immunosensor for AFB1 detection. The precision and accuracy of the immunosensor are verified by comparison with the standard high-performance liquid chromatography method. Overall, this study introduces a novel type of organic ECL nanoemitter and highlights the potential of AgTCNQ nanoshuttles in the development of sensitive and selective ECL biosensors for diverse analytical applications.