Hymenaea courbaril resin-mediated gold nanoparticles as catalysts in organic dyes degradation and sensors in pharmaceutical pollutants

In this study, green synthesis of gold nanoparticles (AuNPs) using aqueous extract from Hymenaea courbaril resin (HCR) is reported. The successful formation, functional group involvement, size, and morphology of the subject H. courbaril resin mediated gold nanoparticles (HCRAuNPs) were confirmed by Ultra Violet-Visible (UV-vis) spectroscopy, Fourier-Transform Infrared spectroscopy (FTIR), and Transmission Electron Microscopy (TEM) techniques. Stable and high yield of HCRAuNPs was formed in 1:15 (aqueous solution: salt solution) reacted in sunlight as indicated by the visual colour change and appearance of surface Plasmon resonance (SPR) at 560 nm. From the FT-IR results, the phenolic hydroxyl (-OH) functional group was found to be involved in synthesis and stabilization of nanoparticles. The TEM analysis showed that the particles are highly dispersed and spherical in shape with average size of 17.5 nm. The synthesized HCRAuNPs showed significant degradation potential against organic dyes, including methylene blue (MB, 85 %), methyl orange (MO, 90 %), congo red (CR, 83 %), and para nitrophenol (PNP, 76 %) up to 180 min. The nanoparticles also demonstrated the effective detection of pharmaceutical pollutants, including amoxicillin, levofloxacin, and azithromycin in aqueous environment as observable changes in color and UV-Vis spectral graph.