Photoluminescence sensing of Pb2+ using cellulose acetate nanofiber decorated with Au nanoparticles

Abstract

Lead (II) is the second most hazardous heavy metal to the environment and humanity, due to its accumulation in the food chain and remaining as a persistent toxin in the environment. Thus, the design and fabrication of effective sensing materials and devices for the speedy detection of lead is a great challenge. Herein, we introduce gold nanoparticles deposited on the surface of electrospun cellulose acetate nanofiber Au@CANFs as photoluminescence sensor for detecting trace amount of lead metal ions based on a photoluminescence quenching approach. Despite that the concentration of cellulose acetate used for fabrication of nanofiber is lower than that previously reported, we observed nanofiber with small diameter and uniform shape. The scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis of the as-prepared sensor reveal the formation of nanofiber structure with diameter 90–200 nm and Au NPs are distributed on the surface of nanofiber with size 15–50 nm. The surface structure and chemical compositions of Au@CANFs were performed by Fourier transform infrared (FTIR) and XPS techniques. The UV-Vis spectra, clearly demonstrating that the sensor displayed localized surface plasmon resonance (LSPR) of Au nanoparticles. Both photoluminescence spectroscopy and Inverted Fluorescence microscopy image demonstrating that the CANFs and Au@CANFs display green emission. Under optimum conditions, the Au@CANFs PL sensor showed high sensitivity for detection of Pb2+ ion within a working range of 0 μg/L to 6 μg/L, R2 = 0.992 and a limit of detection of 0.16 ppb. Based on the obtained results, we anticipate that this PL sensor can be easily extended to tune the sensing performance of different heavy metals.