Study of anti-a antibody conjugated gold nanoparticles as a biomolecular detection probe for a substance in saliva

Abstract

© 2020 Trans Tech Publications Ltd, Switzerland. In this research studied on the conjugation of antibodies on gold nanoparticles (GNPs) and the optimization in term of antibody concentration and albumin blocking concentration. Gold nanoparticles with diameter size of ~20 nm were synthesized via chemical reduction of HAuCl4 with trisodium citrate as reducing and stabilizing agent. Gold nanoparticles and anti-A antibody at various concentrations were mixed and nonspecific binding sites were blocked by using bovine serum albumin (BSA) at various concentrations. The antibody conjugated gold nanoparticles were tested by coagulation with 1% sodium chloride salt solution to obtain the optimal antibody concentration. BSA 50, 100 and 200 μg/mL were added in solution after antibody covered on gold nanoparticles. The solutions were characterized by measuring absorbance spectra. From the results found that the optimal concentration of antibodies and BSA blocking were 45 μg/mL and 50 μg/mL, respectively. The anti-A conjugated gold nanoparticles were tested with saliva of blood group A sample to monitor the specific interaction between antibody on gold surface and antigen in saliva via the change of absorbance spectra.