Preparation of carbon dots-loaded electrospun PVP/PVDF composite membranes for detection of iodide ion

In this paper, a highly selective solid-phase composite fluorescent sensor (BCDS@PVP/PVDF) for detecting iodide ions (I−) was synthesized. This sensor was prepared by electrospinning carbon dots (CDs), polyvinylpyrrolidone (PVP), and polyvinylidene fluoride (PVDF) into a composite nanofiber membrane. Scanning electron microscope (SEM) morphology analysis indicated that the addition of carbon dots had no effect on the spun membranes. Fourier transform infrared spectrometer (FTIR) and X-ray photoelectron spectrometer (XPS) analyses demonstrated that the carbon dots were successfully loaded onto the electrospun membranes. The I− detection experiments demonstrated that the fluorescence quenching phenomenon occurred within the range of 0-100 mg/L, and a linear relationship was observed within the range of 0.3-0.5 mg/L. The detection limit was at 0.17 mg/L. The fluorescence quenching mechanism was initially attributed to dynamic quenching by UV absorption and fluorescence lifetime. This study provides a new approach for the development of portable fluorescence sensors for I− detection.