This study introduced and demonstrated Flow Induced Dispersion Analysis (FIDA) as a fast, one-step method for quantifying proteins directly in human plasma, and FIDA was used to measure the concentration of Human Serum Albumin (HSA) and an anti-HSA antibody. The method tracks changes in an indicator molecule's apparent diffusivity, determined by Taylor Dispersion Analysis, as it binds the target protein. Using fluorescein as the indicator, the researchers quantified HSA in diluted (2%) human plasma in as little as 3 minutes, obtaining results comparable to the standard bromocresol purple assay. Antibody binding was detected at concentrations as low as 1 nM. The work shows FIDA is selective, automatable and tolerant of the plasma matrix, offering a simpler alternative to ELISA that needs only a single affinity interaction rather than surface chemistry and secondary antibodies.