LTP-assisted fabrication of laccase-like Cu-MOF nanozyme-encoded array sensor for identification and intelligent sensing of bioactive components in food.

Nanozymes are potential candidates for constructing sensors due to their adjustable activity, high stability, and high cost-effectiveness. However, due to the lack of reasonable means, designing and preparing efficient nanozymes remains challenging. Herein, inspired by the property of natural laccase, we applied the novel and facile low-temperature plasma (LTP) technology to fabricate a series of different base-ligand Cu metal organic framework (MOF) nanozymes (namely, A-Cu, G-Cu, C-Cu and T-Cu nanozymes) with laccase-like activity successfully. Owing to the different catalytic capacities of four types of base-Cu-MOF nanozymes in the response to five common effective bioactive substances, we constructed the nanozyme-encoded array sensor for the identification of different bioactive compounds. As a result, the four-channel colorimetric sensor array was constructed, in which four laccase-like nanozymes were utilized as the sensing units, achieving high-throughput, high-sensitivity and rapid detection/identification of five common bioactive compounds in the concentration range of 1.5-150 μg mL through different color output patterns. It is worth noting that the as-prepared sensor array can successfully distinguish the natural bioactive compounds in a variety of real samples. Furthermore, with the assistance of smartphones, we also designed a portable smart sensing approach for detecting the bioactive compounds effectively in food. This study has therefore not only provided an effective way for preparation highly effectively nanozymes, but also established a new sensing platform for intelligent sensing of bioactive components in food.