LAUSR

The effect of preformed protein coronas on immunoassays for Dengue nonstructural protein 1 (NS1) immunoassays was investigated. The composition of the protein corona that forms around nanoparticle–antibody conjugates in human serum was characterized, and selected proteins from the corona were used for preformed coronas (human serum albumin and apolipoprotein A1). Coronas were formed and characterized by dynamic light scattering (DLS), and the nanoparticle-conjugate was probed by optical absorption spectroscopy. Immunoassays were run, and performance was quantified by analyzing the strip intensity as a function of NS1 concentration. The preformed coronas influenced the limit of detection (LOD) of the assay and the affinity for the NS1 target (KD). The resulting KD and LODs for the NP–Ab–ApoA1 immunoprobes were 0.83 nM and 1.24 nM, respectively. For the NP–Ab –HSA coronas, the test line intensity was lower by 33% at a given NS1 concentration than for the NP–Ab immunoprobes, and KD was 0.14 nM, a slightly higher affinity. Due to the relatively large error of the negative control, a meaningful LOD for the NP–Ab with HSA coronas could not be determined.