Synergistic effects of gold nanoparticles enhanced the sensitivity of enzyme-linked immunosorbent assay for latex allergens

Abstract

Hevea brasiliensis rubber elongation factor (Hev b1), a non-glycosylated protein, is a notable allergen in natural latex products. This study aims to assess enzyme-linked immunosorbent assay (ELISA) combined with gold nanoparticles (AuNPs) as a Hev b1 detection substrate. AuNP synthesis precursor and reducing agent concentrations were optimized using factorial design and multiple linear regression (MLR). The optimized conditions yielded spherical AuNPs with an average particle size of 73 ± 23 nm. This substrate enhanced detection sensitivity by around 50% compared to the limit of detection of the bare substrate, in the linear range of 0.25–1.75 μg/mL. Additionally, the heightened absorbance intensity observed during Hev b1 ELISA signifies both augmented surface immobilization of the analyte and optical induction arising from the aggregation of suitably small AuNPs (<80 nm) into dimer clusters, supported by discrete dipole approximation (DDA). Overall, the findings highlighted the synergistic effects of AuNPs in enhancing the performance of ELISA for Hev b1 detection.