Mn²⁺-mediated fluorescence enhanced carbon dots to detect 1,3-diphenylguanidine by aggregation-induced quenching and...

1,3-Diphenylguanidine (DPG), an additive widely utilized in industrial production, has been reported to exhibit numerous hazardous effects. However, effective methods for its real-time detection remain limited. In this study, an F, N-codoped carbon dots@Mn²⁺ (F, N-CDs@Mn²⁺) system is successfully developed for the rapid fluorescent detection of DPG. Initially, upon the addition of Mn²⁺, a blue shift (from 489 to 475 nm) is observed in the F, N-CDs@Mn²⁺ system due to chelation-enhanced fluorescence. Following the subsequent introduction of DPG, a significant fluorescence quenching accompanied by a pronounced red shift (from 475 to 501 nm) occurs in the F, N-CDs@Mn²⁺+DPG, owing to aggregation-induced quenching and photoinduced electron transfer. This sensor exhibits a broad linear range spanning from 0 to 10.55 µg/mL, along with a low limit of detection (LOD) of 23.63 ng/mL. Moreover, the F, N-CDs@Mn²⁺ system is combined with RGB analysis for the real-time detection of DPG, yielding satisfactory results with an LOD of 37.12 ng/mL and recoveries ranging from 97% to 114.33%. Consequently, highly sensitive and selective detection of DPG is achieved, providing a real-time visual analytical platform for safeguarding human health and enabling early warning of environmental pollution.