Graphene quantum dots functionalized dimercaptosuccinic acid-putrescine as a fluorescence probe for the determination of As(III)

Here, a novel fluorescence probe based on graphene quantum dots (GQDs) capped with dimercaptosuccinic acid (DMSA) and putrescine (PUT) for fast and selective determination of As(III) was reported. Electron transmission microscopy and Fourier transform infrared spectroscopy have been used to characterize the prepared DMSA-PUT capped GQDs. Due to high affinity of DMSA-PUT functional groups to As(III), the FL intensity of the designed DMSA-PUT capped GQDs was linearly quenched in the presence of As(III) from 0.025 to 150 ppb with suitable reproducibility and repeatability. Fluorescence response of DMSA-PUT capped GQDs in the presence of several ions at various pHs were studied revealing suitable selectivity of the developed sensor for As³⁺. Statistical student’s t-test analysis of the standard NIST SRM 2669 and SRM 1572b confirmed the accuracy of the method against systematic and constant errors (> 95% recovery with < 5% RSD). The prepared fluorescent probe shows a limit of detection of 0.0132 ppb, which is appropriate for detecting hazardous As(III) in drinkable ground waters. The developed sensor was utilized for fluorescence probing of As³⁺ in underground water samples with satisfactory analytical results.