In the production of AuNPs conjugated with TBSV-IgG, the particle size is inversely proportional to the sodium citrate volume. In the TBSV-IgG antibody-AuNP conjugation,
the antibody was absorbed on the AuNP surface. The effects of pH values on the conjugation were studied by evaluating the absorbance between 400nm and 650 nm. Also, the main purpose of the assay was to allow visual evaluation, so it was only used as a qualitative assay to detect contamination at a threshold level.