Electrospun Cellulose Acetate/Maleic Acid Functionalized Gold Nanoparticles as Pb(II) Ions Colorimeter Senser Strip

Abstract

This study investigates the synthesis of gold nanoparticles and surface modifications to enable their utilization as a colorimetric sensor strip on electrospun nanofibrous. Additionally, it utilizes cellulose acetate electrospun fiber preparations as substrates for loading the gold nanoparticles. In order to produce gold nanoparticles, citrate reduction was employed, followed by modification with maleic acid (MA-GNPs).  MA-GNPs were significantly more selective for Pb²⁺ than for other ions (Co²⁺, Cu²⁺, Hg²⁺, Ni⁺), according to the results. Following the introduction of Pb²⁺, the solutions exhibited a color change from red to blue or purple, which was attributed to the aggregation of nanoparticles, as determined by UV-Vis spectrometry. An optical band indicative of GNPs and MA-GNPs was detected at an estimated wavelength of 520 nm. Approximately 600 nanometers after the addition of Pb²⁺, the intensity of the solution progressively decreased to 520 nanometers, and a new band emerged. To fabricate cellulose acetate nanofibrous via electrospinning, the impact of solvent ratios, polymer concentrations, and process conditions were investigated. The ideal parameters for the fabrication of the substrate were as follows: 15%w/w polymer solution, 15 kV electrospinning voltage, 15 cm needle-to-collector distance, and 48 hours of collecting time. In order to examine the color change of the prepared strip, it is observed that the strip transforms from red to blue upon exposure to Pb²⁺ ions of varying concentrations, just as it does in solution form. An examination of water samples indicated that the strip remained colorless when tested with DI water. However, testing with wastewater sourced from a battery facility identified a transformation of the strip from red to purplish blue. This is equivalent to an estimated lead concentration of 40 parts per million. The outcomes showcased the capacity of the discolored strips to identify the preliminary concentration of lead ions, suggesting potential for future advancements in this area.