GSH-AuNCs@ZIF-8 as chemiluminescence imaging label for high-throughput and ultrasensitive detection of THC and THC-COOH

Traditional quantitation methods for Δ9-tetrahydrocannabinol (THC) require multi-step sample pretreatment, specialized instruments and trained operators. There is a demand for a simple, rapid, reliable, and sensitive method for detecting THC. Herein, a novel chemiluminescence (CL) imaging protocol was developed for ultrasensitive and high-throughput determination of Δ9-tetrahydrocannabinol (THC) and its metabolite THC-COOH, as CL imaging offers advantages such as free of external light source, high sensitivity, and ease of operation. GSH-AuNCs@ZIF-8 with strong CL catalytical property was prepared by encapsulating glutathione-modified gold nanoclusters (GSH-AuNCs) into zeolitic imidazolate frameworks-8 (ZIF-8). The integration of GSH-AuNCs@ZIF-8 with a disposable immunosensor array resulted in impressively low limits of detection (down to 0.04 ng mL-1 and 0.09 ng mL-1 for THC and THC-COOH, respectively) and high throughput (90 tests h-1). When applied to rat plasma samples, it exhibited satisfactory recoveries (89.68%-104.54%) and yielded results consistent with those obtained using the standard method. With high sensitivity and throughput, acceptable precision, and straightforward operation, the proposed protocol demonstrated good applicability for rapid, on-site detection, and law enforcement regulation of THC. Moreover, the protocol explored the chemiluminescence property of GSH-AuNCs@ZIF-8 and utilized it as a CL imaging label, opening new directions for the application of MOF composites.