Signal upscaling with the sequential addition of reagents for enhancement of detection sensitivity

Abstract

In the present study, a simplified model system for signal upscaling using sequential addition of reagents was aimed to be developed using gold nanoparticles (AuNPs). For achieving this goal, two approaches were investigated: streptavidin-biotin and click chemistry. In the streptavidin-biotin approach, modified parameters were the following: concentration of biotin-AuNPs, blocking of the plate surface with biotin solution, incubation time, and detergent concentration. In the click chemistry approach, varied parameters were: different additives in PBS, vortexing and sonication of AuNPs (derivatized with azide and alkyne), the concentration of a detergent solution. Two types of measurements were made in these approaches: absorbance at 572 nm (corresponding to AuNP absorption maximum) and brightfield microscopy (for assessment of homogeneity of the formed surface). Although signal upscaling could not be achieved during this thesis, the knowledge gained from this experience will be used as the basis for further research.