Silicon quantum dots-based fluorescent sensor for the detection of cobalt with high sensitivity and selectivity

Fluorescent silicon quantum dots (Si QDs) were hydrothermally synthesized from a mixture of 3(2-aminoethylamino) propyl (dimethoxymethylsilane) (AEAPDMMS) and poly(vinylpyrrolidine) (PVP). The resulting Si QDs exhibited good water solubility and high stability. Under the optimized conditions, the probe revealed an excellent linear fluorescence quenching effect on Co2+ ranging from 1 µmol/L to 120 µmol/L with a limit of detection of 0.37 µmol/L (based on 3s/k). The quenching mechanism was studied, showing that static quenching (SQE) causes the main effect. Furthermore, the test paper based on Si QDs was prepared, which is cost-effective, high sensitivity, good selectivity, easy to use and show excellent anti-interference capability. This method was applied to analyze the content of Co2+ in environmental water samples with satisfying results.