Abstract
This study optimizes immunofluorescence techniques using gold nanoparticles (AuNPs) to improve visualization of endothelial nitric oxide synthase (eNOS) in gill tissue. Two types of AuNP dispersions, stabilized in phosphate buffered saline (PBS) and citrate buffer (CB), were evaluated for their imaging performance. AuNPs suspended in PBS provided significantly better optical contrast due to uniform distribution and effective tissue attachment, whereas citrate-suspended AuNPs exhibited aggregation, resulting in reduced contrast. These results highlight the influence of suspension media on AuNP performance, particularly in balancing fluorescence signals to improve contrast. The PBS suspension allowed clearer visualization of eNOS, highlighting the role of AuNP compatibility in improving immunofluorescence results. This study highlights the importance of strategic selection of AuNP dispersions in contrast agent design and provides insights for advanced imaging applications where sensitivity and accurate localization of biomolecules are essential. By refining the use of AuNPs as contrast enhancers, this approach offers potential improvements in bioimaging accuracy, facilitating more precise visualization in complex tissue environments.