Dual-phase nanoplasmonic sensing platform for monitoring blood protein adsorption and its coagulation in vitro

Protein adsorption onto solid surfaces is an immanent and spontaneous phenomenon that occurs in many fundamental biomedical applications. Recent research mainly focuses on collectively measuring the protein behaviors in confined localized nanosensing areas, whereas ignoring the ambient aqueous variation that directly affects protein behavior, such as the hydrogen bonding network in protein-water which serves as a crucial and mutually constrained environment. Herein, we develop a novel dual-phase plasmonic sensing platform with a gold nanopyramid array (GNPA), simultaneously monitoring protein binding at the nanosensing surface and the variation tendency of hydrogen bonding in aqueous solution. Two types of protein adsorption and their solution variation are explored: we first investigate bovine serum albumin (BSA) adsorption and its variation tendency of hydrogen bonding formation and fracture in water. Then we apply the sensing chip to monitor the fibrinogen adsorption and its real-time conversion to fibrin in an in vitro model of simulated blood coagulation, where the synchronous sensing signals of localized surface plasmon resonance (LSPR) and aqueous hydrogen bonding variations are acquired. It helps to reveal the connection between hydrogen bonding variations in protein-water solution and protein adsorption behaviors at the surface, a meaningful finding for comprehending the initiation of abnormal blood coagulation and the related thromboembolism disease. Moreover, the proposed dual-phase sensing strategy opens a new path for a wider variety of applications, ranging from monitoring microenvironmental changes inside the human body to detecting the water contamination or environmental pollutants.