Abstract: Point-of-care (POC) devices have expanded rapidly in recent decades, driven by increasing demand for decentralized diagnostics. However, many remain limited to detecting diseases at high biomarker concentrations, often after symptoms have already developed. Early detection is critical for conditions such as cancer and Alzheimer’s disease, where timely intervention can significantly improve patient outcomes. A highly integrated and sensitive microfluidic-based biosensing system is under development to address this need. This system consists of a microfluidic channel for self-processing blood samples, a biosensor array for multiplex biomarkers detection, and a portable signal readout system. The surface-modified microchannel utilizes inertial migration and microfilters to separate plasma within a capillary-driven flow, while gold-interdigitated electrodes functionalized with polyethylene glycol (PEG) and specific antibodies enable precise antigen detection using capacitive signals generated by antigen-antibody conjugation. Additionally, a non-sensing pad was deployed upstream in the microchannel, coated with antibodies specific to cross-reactive antigens, capturing these antigens before the plasma reached the biosensor, thereby enhancing biosensing selectivity. This platform provides a compact and efficient solution for early disease detection, with potential applications in clinical and POC settings. In our study, the clean plasma was successfully separated from 5 μl of whole blood sample using the microfluidic channel within capillary-driven flow within 10
seconds with 99.8% purity and delivered to the biosensing chambers where the biosensors were located. CA-125 and Aβ42/40 peptides were successfully detected at low detection limits (e.g., Aβ42 detected at 2 pg/mL) for ovarian cancer and Alzheimer’s diagnosis, respectively. The successful development of this micro biosensing system has the potential for broader disease detection applications in a POC setting.

Bio: Yudong Wang is a graduating Ph.D. candidate in the Department of Mechanical and Industrial Engineering at the New Jersey Institute of Technology. Since 2018, he has been conducting micro-/nanofabrication research as a visiting researcher at the Center for Functional Nanomaterials, Brookhaven National Laboratory. His work since 2020 has focused on developing micro biochips by integrating microfluidics, protein analysis, micro-/nanofabrication, and biosensing technologies. With over 7 years of experience in microfluidic-based biosensing devices and 3 years in translational research for point-of-care medical devices, his research explores passive self-separation mechanisms, lab-on-a-chip disease biosensors, electrochemical biosensor optimization, and nanomaterials for biomedical applications.