Synthesis and characterization of gold nanoparticles as a sensing tool for the lateral flow immunoassay development

Gold nanoparticles (AuNPs) have acquired an imperative and noteworthy position in the field of clinical diagnostic methodologies and therapeutics. Among the metal nanoparticles, AuNPs have always been the choice of sensor material for the development of optical biosensors. The simple, definitive, and tunable properties of AuNPs are expedient for the development of several applications. Numerous lateral flow immunoassays (LFIs) utilize AuNPs for colorimetric detection of various analytes. Herein, the synthesis of colloidal AuNPs in the size range of 12–68 nm is reported along with the calculation of physicochemical parameters. Size, shape, surface morphology, and charge characterization of the AuNPs were performed using various techniques. The stability of the AuNPs stored in various photo-physical conditions was also studied for 60 days and it was observed that AuNPs are stable in dark and cold conditions for a longer time. The AuNPs of size 30 nm displayed excellent stability and color intensity. The calculation of various physicochemical parameters may assist researchers in selecting the appropriate AuNPs based on specific requirements. Synthesized spherical AuNPs in the colloidal phase possesses the potential for application in the design and development of colorimetric biosensors-based LFIs. •Synthesis of various sizes of gold nanoparticles.•Theoretical calculation of physical parameters.•Stability study of synthesized gold nanoparticles.•Filtration and particle aggregation analysis.