CDs/ZnO composite material with solid state fluorescence performance for quantitative determination of methyl red content and antibacterial properties

Abstract A water-soluble probe composite material (CDs/ZnO) was synthesized by microwave pyrolysis methods of citric acid, urea and zinc oxide (ZnO) with aggregation-induced emission activity. We creatively realized the composite of CDs and nano-ZnO in the form of foam, then used as bactericide for the first time and showed excellent antibacterial properties. Also, the composite materials overcame the problem of aggregation-induced quenching (ACQ) and realized solid-state emission. The materials had two different emission centers, and the two emission peaks were varied with the change of excitation wavelength. Furthermore, Methyl red (MR) showed fluorescence quenching for CDs/ZnO with obvious linear correlation, which demonstrated potential in the measurement of MR in dyeing wastewater. The CDs/ZnO we obtained perfectly inherited the advantages of CDs and nano ZnO, it has not just no cytotoxicity to cells, but also has a good killing effect on bacteria. Hence, this work shows significant adaptable fluorescence-based protocol with enormous potential applications in biology.