A fluorescent sensor for the detection of multi-molecule species based on redox reaction

• Fluorescent polymer nanodots (PNDs) were prepared and the fluorescence of PNDs can be selectivity quenched by Fe3+.
• Reducers could be detected based on Fe3+-PNDs system.
• The fluorescent sensor based on Fe2+-PNDs system is capable of detection of oxygenants.
• The fluorescent sensor is also suitable for the detection of Fe2+.

Here we demonstrate a novel fluorescent sensor for multi-molecule detection based on the selectivity quenching of Fe3+ and polymer nanodots (PNDs). The oxygenants such as hydrogen peroxide (H2O2), potassium permanganate (KMnO4), and potassium dichromate (K2Cr2O7) could be detected by the decrease of the fluorescence intensity for the formation of Fe3+-PNDs when they were present in the system of Fe2+-PNDs. Similarly, the reducers (e.g., ascorbic acid (AA), trisodium citrate (NaCit), and cuprous chloride (CuCl)) could be detected according to the increased fluorescence intensity as they were existed in the system of Fe3+-PNDs. Additionally, Fe2+ could also be determined when it was added to the oxygenant-PNDs system for the quenched fluorescence. We believe that this work would encourage the development of the detection platform of multi-molecules and the crossing discipline of fluorescent sensor and electrochemistry.