(549e) The Modification of Nanocellulose with Atomic Precise Metal Nanoclusters

New functional materials are of great importance for the design of highly sensitive and high-precision sensors for chemicals and hazardous substances. The selective, precise, and swift measurement of chemical substances is critical in various areas such as environmental protection, the food industry, occupational safety, and forensics. Recently, the burgeoning metal nanoclusters (MNCs) with well-resolved crystal structures show great prospects in fundamental research and various applications including luminescence, medicine, catalysis, energy, and biology owing to their unique physiochemical properties. Additionally, with the ever-growing interest in sustainable materials, nanoclusters are assembled with renewable nano cellulose together to serve as color-changing ink, sensors for heavy metals, and antibacterial materials based on the intense fluorescence and biocompatibility of MNCs. However, it remains unclear which MNC in the mixture plays a major role in the final properties of nanomaterials since the MNCs used in reported MNCs/nanocellulose materials are mixtures of MNCs, not monodispersed and atomic precise MNCs. And the understanding of the correlation between MNCs’ structure and properties is limited till now for the lack of suitable nano-assembling models.

In this study, a series of stable and high fluorescence homo- and heterogeneous nanoclusters were prepared and characterized by an array of advanced instruments including UV-vis spectroscopy, ESI-MS, XPS, and single-crystal X-ray diffraction. These nanoclusters were further deposited on the uniform nanocellulose crystals (NCs) to form sensors to detect heavy metal ions in water. Interestingly, the quantity yield of MNCs has been significantly improved in the presence of NCs, which suggests that NCs could improve the sensitivity of the sensor to metal ions’ detection in water. Moreover, the dopant of Cu species in MNCs has been proven to be the key to the high stability and high sensitivity of MNCs-NCs nanocomposites in the nanosensor design. Besides, the pure silver cluster deposited on NCs is not only sensitive to metal ions in water but also shows an excellent anti-bacterial property. This work provides a good example of the design and application of atomic precise MNCs-NCs nanocomposites in the field of highly-sensitive sensors.