Biosensors and microdevices for clinical sample testing

Our lab develops electrochemical biosensors and microfluidic platforms to detect clinically relevant biomarkers in small-volume samples, such as whole blood, urine and serum. Our work integrates surface chemistry, microfluidics and electrochemical detection to create platforms capable of performing immunoassays in a miniaturized and automated format. These systems feature computer-controlled, pneumatically actuated microvalves that allow for precise sample routing and reagent delivery using as little as 5 µL to 15 µL of a sample. The goal is to translate complex immunoassays into robust, user-friendly diagnostic tools suitable for clinical and point-of-care settings.

Over the years, we have developed a range of approaches for analyzing extracellular vesicles, cytokines and disease-specific antibodies from clinical samples. For example, we designed a novel microtiter plate assay to detect surface markers of preeclampsia on urinary extracellular vesicles using antibody-functionalized gold nanoparticles doped with redox-active metal ions to enhance signal and binding affinity.

The figure below shows an automated microfluidic platform we introduced. This platform has active mixing for colorimetric glucose detection from just 5 µL of whole blood, enabling rapid analysis in under 10 minutes.

Electrochemical microtiter plate for extracellular vesicle (EV) surface marker detection Developing an electrochemical microfluidic biosensor

This figure outlines recent efforts to develop an electrochemical microfluidic biosensor capable of distinguishing two immune-mediated thrombotic disorders — vaccine-induced immune thrombotic thrombocytopenia (VITT) and heparin-induced thrombocytopenia (HIT) — using only 15 µL of serum.

Automated microfluidic device for plasma separation and colorimetric detection of biomarkers in 5 ul of whole blood Rapid and sensitive clinical diagnostics

This figure illustrates the team's ongoing efforts to combine microfluidic automation, novel surface chemistries and electrochemical detection for rapid and sensitive clinical diagnostics.

A microfluidic device with integrated electrodes for detecting biomarkers of thrombotic disorders Detecting VITT and HIT

An automated microfluidic electrochemical biosensor detects vaccine-induced immune thrombotic thrombocytopenia (VITT) and heparin-induced thrombocytopenia (HIT) antibodies using PF4 or cross-linked PF4 as selective antigenic targets.

Key publications

Cedillo-Alcantar DF, Kanack A, Lee S, Gonzalez-Suarez AM, Gwon K, Mauch E, Revzin A. Automated microfluidic electrochemical biosensor for the detection of immune-mediated thrombotic disorders. medRxiv. 2025.

Lee S, Gonzalez-Suarez AM, Huang X, Calvo-Lozano O, Suvakov S, Lechuga LM, Garovic VD, Stybayeva G, Revzin A. Using electrochemical immunoassay in a novel microtiter plate to detect surface markers of preeclampsia on urinary extracellular vesicles. ACS Sensors. 2023.

Gonzalez-Suarez AM, Stybayeva G, Carey WA, Revzin A. Automated microfluidic system with active mixing enables rapid analysis of biomarkers in 5 μL of whole blood. Analytical Chemistry. 2022.

Rahimian A, Siltanen C, Feyzizarnagh H, Escalante P, Revzin A. Microencapsulated immunoassays for detection of cytokines in human blood. ACS sensors. 2019.