Aggregation-induced phosphorescence quenching method for the detection of picric acid based on melamine-passivated Mn-doped ZnS quantum dots

Melamine (MA)-passivated Mn-doped ZnS quantum dots (QDs) were synthesized by a hydrothermal method . The MA-passivated QDs can form a charge-transfer complex with picric acid (PA) at 80 °C, thereby quenching the phosphorescence of the QDs. A sensitive method for detecting PA was established based on this principle of phosphorescence quenching . When the PA concentration ranged from 2.0 to 180 ng mL −1 , the concentration was linearly related to the quenching intensity of the QDs, with a detection limit of 1.4 ng mL −1 . When applied to detect PA in environmental water samples, the proposed method showed superior analytical performance compared with other PA analysis methods. Furthermore, we verified the static quenching mechanism by density functional theory . MA on the surface of QDs and PA formed a stable structure with a binding energy of 12.43 eV.