Synthesis of biogenic silver nanoparticles from apricot kernel extracts for the colorimetric determination of gold

Gold is abundant in nature, however, precise and reliable analytical methods for its detection are required stemming from its increasing prevalence in environmental, biological, and industrial systems, as well as the growing interest in understanding its function in living organisms and its effects on human health. This study investigates the use of biogenically synthesized silver nanoparticles (AgNPs) for the preconcentration and determination of gold ions prior to determination by UV-Vis spectrophotometry. AgNPs were synthesized by reducing silver nitrate through the use of an apricot kernel extract as both reducer and stabilizer agent. The colloidal yellowish AgNPs interacted with gold ions, leading to a distinct color change and a considerable decrease in the surface plasmon resonance (SPR) intensity at 415 nm in the UV-Vis absorption band, indicating a highly sensitive and selective colorimetric detection of gold ions. Under optimized conditions, the proposed method achieved satisfactory limit of detection (LOD) and limit of quantification (LOQ) values of 2.9 and 9.7 mg/L, respectively. A matrix matching calibration strategy was used to enhance quantification accuracy, resulting in satisfactory percent recoveries from waste mud samples (88-112%). Overall, the results validated the developed method as a green, simple, rapid, and accurate analytical approach to the determination of gold.