Determination of metronidazole by a flow-injection chemiluminescence method using ZnO-doped carbon quantum dots

ZnO-doped carbon quantum dots (CQDs) were prepared by the chemical oxidation of activated carbon followed by zinc acetate impregnation and precipitation. The ZnO-doped CQDs had a stable fluorescence and a high fluorescence quantum yield. The fluorescence of the ZnO-doped CQDs can be quenched by reduction with metronidazole, allowing a flow-injection chemiluminescence method to be used to determine the metronidazole content in tablets. Under optimum conditions, there was a good linear relation between the concentration of metronidazole and the intensity of chemiluminiscence. The linear concentration range examined was 7.5 × 10−4−2.5 × 10−8 g/mL with r = 0.9996 and a detection limit of 1.08×10−10 g/mL.