Biosensors and microdevices for clinical sample testing
Our lab develops electrochemical biosensors and microfluidic platforms to detect clinically relevant biomarkers in biological fluids such as blood or urine. Over the years, we have developed a range of approaches for analyzing extracellular vesicles, cytokines and disease-specific antibodies from clinical samples. For example, as shown in the figure below, we designed a novel electrochemical microtiter plate 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.
Electrochemical immunoassay for detecting surface markers on extracellular vesicles
This electrochemical immunoassay developed by our team employs gold nanoparticles functionalized with antibodies for target specificity and with metal ions for electrochemical redox signals. This immunoassay is performed in a custom-made microtiter plate that can detect extracellular vesicle surface markers with greater sensitivity compared to more traditional ELISA approaches.
Our team relies heavily on microfluidics to create devices capable of performing multistep assays in a miniaturized and automated format. These devices 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 figure below shows an example of an automated microfluidic platform we introduced. This platform features onboard separation of plasma from blood, plasma routing and mixing with different reagents to detect three biomarkers from as little as 5 µL of whole blood. This work can be completed in under 10 minutes.
Automated microfluidic device allows for the isolation of plasma and detects several biomarkers from 5 µL of blood
Our team developed a microfluidic device that uses a set of integrated computer-controlled microvalves to perform an automated workflow based on an input of 5 µL of blood. The steps of the workflow include plasma separation, delivery of plasma into analysis chambers, as well as mixing of samples and reagents in the device. Using onboard automation and mixing allows us to limit assay time to 10 minutes.
Another biosensing technology developed in the lab recently features a microfluidic device with integrated electrodes to detect autoantibodies associated with two hematologic disorders: vaccine-induced immune thrombotic thrombocytopenia (VITT) and heparin-induced thrombocytopenia (HIT). This microfluidic device is designed for point-of-care testing. It eliminates human handling while providing a sensitive measurement based on a small volume of a biological sample.
The figure below shows an automated microfluidic electrochemical biosensor that detects VITT and HIT antibodies using selective antigenic targets.
Automated microfluidic device with integrated electrodes for detecting autoantibodies
This device, which combines onboard microvalves with miniature electrodes, is used for electrochemical detection of biomarkers using a small sample volume. We demonstrated clinical utility of this device by detecting autoantibodies associated with thrombotic disorders. However, like most technologies developed by our team, this device has broad applicability across a range of clinical applications.
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.