Synergistic enhancement of potassium permanganate-induced chemiluminescence by nitrogen and silver carbon dots and formaldehyde for selective detection of tannin

In this study, nitrogen and silver doped carbon dots (NAg-CDs) were synthesized via a simple and environmentally friendly hydrothermal one-pot method and were utilized in combination with formaldehyde to enhance potassium permanganate-induced chemiluminescence (CL). Remarkably, a chemiluminescent enhancement of approximately 448-fold was observed in the NAg-CDs-KMnO4-HCHO system than in the KMnO4-HCHO system. The enhanced CL intensity of the NAg-CDs-KMnO4-HCHO system can be significantly quenched by tannin. On this basis, we developed a simple, rapid, sensitive, and selective flow injection CL method for the detection of tannin, featuring a linear range of 0.4–10.0 μM and a detection limit of 43.0 nM. Furthermore, we effectively applied this method to the detection of tannin in red wine and tea samples, and the standard recoveries were 98.6%104.9%.