Glutathione-mediated copper sulfide nanoplatforms with morphological and vacancy-dependent photothermal catalytic activity for multi-model tannic acid assays.

Interface engineering and vacancy engineering play an important role in the surface and electronic structure of nanomaterials. The combination of the two provides a feasible way for the development of efficient photocatalytic materials. Here, we use glutathione (GSH) as a coordination molecule to design a series of CuS nanomaterials (CuS-GSH) rich in sulfur vacancies using a simple ultrasonic-assisted method. Interface engineering can induce amorphous structure in the crystal while controlling the formation of porous surfaces of nanomaterials, and the formation of a large number of random orientation bonds further increases the concentration of sulfur vacancies in the crystal structure. This study shows that interface engineering and vacancy engineering can enhance the light absorption ability of CuS-GSH nanomaterials from the visible to the near-infrared region, improve the efficiency of charge transfer between CuS groups, and promote the separation and transfer of optoelectronic electron-hole pairs. In addition, a higher specific surface area can produce a large number of active sites, and the synergistic and efficient photothermal conversion efficiency (58.01%) can jointly promote the better photocatalytic performance of CuS-GSH nanomaterials. Based on the excellent hot carrier generation and photothermal conversion performance of CuS-GSH under illumination, it exhibits an excellent ability to mediate the production of reactive oxygen species (ROS) through peroxide cleavage and has excellent peroxidase activity. Therefore, CuS-GSH has been successfully developed as a nanoenzyme platform for detecting tannic acid (TA) content in tea, and convenient and rapid detection of tannic acid is achieved through the construction of a multi-model strategy. This work not only provides a new way to enhance the enzyme-like activity of nanomaterials but also provides a new prospect for the application of interface engineering and vacancy engineering in the field of photochemistry.