Ordered Porous Layer Interferometry for Dynamic Observation of Non-Specific Adsorption Induced by 1-Ethyl-3-(3-(dimethylamino)propyl) Carbodiimide

Nonspecific adsorption (NSA) seems to be an impregnable obstacle to the progress of the biomedical, diagnostic, microelectronic, and material fields. The reaction path of bioconjugation can alter the surface charge distribution on products and the interaction of bioconjugates, an ignored factor causing NSA. We monitored exacerbated NSA introduced by a 1-ethyl-3-(3-(dimethylamino)propyl) carbodiimide (EDC) addition reaction, which cannot be resistant to bovine serum albumin (BSA) or polyethylene glycol (PEG) antifouling coating and Tween-20. And the negative effects can be minimized by adding as low as 7.5 × 10 –6 M N -hydroxysulfosuccinimide (sulfo-NHS). We applied ordered porous layer interferometry (OPLI) to sensitively evaluate the NSA that is difficult to measure on individual particles. Using the silica colloidal crystal (SCC) film with Fabry–Perot fringes as in situ and real-time monitoring for the NSA, we optimized the surface chemistry to yield a conjugate surface without variational charge distribution. In this work, we propose a novel approach from the perspective of the reaction pathway to minimize the NSA of solely EDC-induced chemistry.