We are an analytical and bioanalytical chemistry laboratory focusing on the study of biological nanoparticles such as exosomes, protein aggregates, protein biomarkers, and the use of gold nanoparticles and colloids to develop new bioassays and diagnostic tests for clinical applications based on the optical properties of gold nanoparticles. We collaborate with biomedical and veterinary science researchers to address the early detection and diagnosis of diseases in humans and animals (infectious diseases, cancer and neurodegenerative diseases). Our work has led to the development of a rapid blood test, D2Dx immunity test, to measure the immune health and status in humans and livestock animals. We specialize in dynamic light scattering (DLS) technique not only as a tool for nanoparticle size analysis, but also as an optical detection platform for label-free bioassay development.