Phenylalanine stabilized copper nanoclusters for specific destruction of Congo red and bacteria in aqueous solution

A simple preparation method of phenylalanine stabilized copper nanoclusters (Phe-CuNCs) was reported. The Phe-CuNCs were active for specific destruction of Congo red (CR) in aqueous solution under natural light irradiation, showing fast, efficient and stable catalytic activities. The catalytic reaction followed first-order kinetics equation, and a linear relation of ln (At/A0) vs. time was observed. The Phe-CuNCs obtained more electrons to accelerate decolorization of CR in the presence of H2O2. The catalytic efficiency of Phe-CuNCs remained above 70% even after 10 cycles of reactions, showing economy and efficiency. The Phe-CuNCs showed remarkable antibacterial activity against both Escherichia coli and Staphylococcus aureus. Meanwhile, the bacterial damage was visualized by scanning electron microscopy (SEM). In addition, the Phe-CuNCs are not toxic to normal cells (HL-7702) and tumor cells (HepG2) even at high concentrations, whereas Phe-CuNCs can efficiently kill bacteria. Thus, Phe-CuNCs may be a promising nanomaterial for specific degradation of Congo red in aqueous solution as well as an adjuvant for treatment of microbial infections.