Monitoring Red Blood Cells Agglutination Using Screen-Printed Electrodes: A Multimodal Voltammetric and Impedimetric Study Via Antigen-Antibody Sensing Approach

Conventional ABO/Rh blood typing relies on agglutination testing, which requires red blood cells (RBC) suspension preparation, centrifugation, and manual interpretation steps that are impractical in emergency or resource-limited settings and are further complicated by matrix effects such as rouleaux formation and cold agglutinins. Electrochemical transduction offers a rapid, sensitive, label-free alternative suited to turbid, unprocessed samples where optical methods fail, since immunoagglutination modulates reporter molecule signal at the electrode surface and produces measurable changes in faradaic process and interfacial charge transfer resistance. Prior work in this space included microfluidic devices, ZnO nanowire integrated interdigitated electrodes and pencil graphite electrodes that has demonstrated agglutination-dependent electrochemical signatures, but these platforms are quite costly coupled with tedious design typically requiring sample pre-processing, rely on a single detection modality, and often evaluate only partial ABO compatibility. In our research we present a disposable screen-printed electrodes (SPE) platform using redox mediator for observing degree of blood clot formation in undiluted whole blood, without any pre-processing steps with simple instrumentation. RBC antibodies immobilized on the SPE surface capture antigen–antibody binding events, characterized using voltammetry techniques such as square wave voltammetry (SWV) and differential pulse voltammetry and electrochemical impedance spectroscopy (EIS) to monitor electrochemical response during RBC agglutination Vs non-agglutination processes. This work establishes low-cost, disposable electrode configurations as a rapid, sensitive, and field-deployable alternative to conventional and nanostructured/microfluidic blood-typing platforms, with direct relevance to emergency transfusion medicine, blood banks, and point-of-care diagnostics.