A microfluidic approach to evaluating surface protection from nonspecific antibody adsorption

Nonspecific antibody adsorption to solid surfaces remains a challenge in the development and use of formulations for immunotherapies, as it can compromise antibody structure and therapeutic function. Here, we introduce a photoluminescent carbon dot (C-dot) nanointerface integrated within a microfluidic platform for real-time, quantitative evaluation of antibody adsorption and surface protection strategies. Surface-immobilized C-dots exhibited photoluminescence quenching due to interactions with antibodies, thereby reporting on real-time adsorption to the surface of the microfluidic device. The approach combines tailored C-dot synthesis and their covalent immobilization onto the microchannel surface, while fluorescence microscopy enables continuous monitoring of antibody adsorption under flow. Using this approach, we evaluated the performance of surface-protecting surfactant molecules. The platform provided reproducible, concentration-resolved measurements across therapeutically relevant antibody concentrations. This strategy offers a time- and material-efficient route for screening anti-fouling agents, guiding the rational design of antibody-compatible surfaces. More broadly, the use of the C-dot nanointerface integrated with microfluidics establishes a versatile strategy for studying protein-surface interactions for immunosensing applications.