Design and Demonstration of Tunable Amplified Sensitivity of AlGaN/GaN High Electron Mobility Transistor (HEMT)-Based Biosensors in Human Serum.

We have developed a swift and simplistic protein immunoassay using aptamer functionalized AlGaN/GaN high electron mobility transistors (HEMTs). The unique design of the sensor facilitates protein detection in a physiological salt environment overcoming charge screening effects, without requiring sample preprocessing. This study reports a tunable and amplified sensitivity of solution-gated electric double layer (EDL) HEMT-based biosensors, which demonstrates significantly enhanced sensitivity by designing a smaller gap between the gate electrode and the detection, and by operating at higher gate voltage.

Investigation of Electrical Stability and Sensitivity of Electric Double Layer Gated Field-Effect Transistors (FETs) for miRNA Detection.

In this research, we developed a miRNA sensor using an electrical double layer (EDL) gated field-effect transistor (FET)-based biosensor with enhanced sensitivity and stability. We conducted an in-depth investigation of the mechanisms that give rise to fluctuations in the electrical signal, affecting the stability and sensitivity of the miRNA sensor. Firstly, surface characteristics were studied by examining the metal electrodes deposited using different metal deposition techniques.

A microfluidic platform integrated with field-effect transistors for enumeration of circulating tumor cells.

Circulating tumor cells (CTCs) are one of the promising cancer biomarkers whose concentrations are measured not only in the initial diagnostic stages, but also as treatment progresses. However, the existing methods for CTC detection are relatively time-consuming and labor-intensive. In this study, a new microfluidic platform integrated with field-effect transistors (FETs) and chambers for the trapping of CTCs was developed.

Miniaturized Biomedical Sensors for Enumeration of Extracellular Vesicles.

In this research, we have realized a rapid extracellular vesicle (EV) quantification methodology using a high field modulated AlGaN/GaN high electron mobility (HEMT) biosensor. The unique sensing structure facilitated the detection of the sub-cellular components in physiological salt environment without requiring extensive sample pre-treatments. The high field operation of GaN HEMT biosensor provides high sensitivity and wide dynamic range of detection of EVs (10⁷⁻10 EVs/mL).

Dynamic monitoring of transmembrane potential changes: a study of ion channels using an electrical double layer-gated FET biosensor.

In this research, we have designed, fabricated and characterized an electrical double layer (EDL)-gated AlGaN/GaN high electron mobility transistor (HEMT) biosensor array to study the transmembrane potential changes of cells. The sensor array platform is designed to detect and count circulating tumor cells (CTCs) of colorectal cancer (CRC) and investigate cellular bioelectric signals. Using the EDL FET biosensor platform, cellular responses can be studied in physiological salt concentrations, thereby eliminating complex automation.

Risk stratification of heart failure from one drop of blood using hand-held biosensor for BNP detection.

Continued risk assessment by evaluating cardiac biomarkers in healthy and unhealthy individuals can lower the mortality rate of cardiovascular diseases (CVDs). In this research, we have developed a hand-held biosensor system to rapidly screen for brain natriuretic peptide (BNP) from a single drop of whole blood. The sensor methodology is based on extended gate design of electrical double layer (EDL) field effect transistor (FET), that can directly detect BNP in whole blood, without extensive sample pre-treatments, thereby eliminating the limitations of charge screening in high ionic strength solutions.

Single Drop Whole Blood Diagnostics: Portable Biomedical Sensor for Cardiac Troponin I Detection.

Detection of disease biomarkers from whole blood is very important in disease prevention and management. However, new generation assays like point-of-care or mobile diagnostics face a myriad of challenges in detecting proteins from whole blood. In this research, we have designed, fabricated, and characterized a portable biomedical sensor for the detection of cardiac troponin I (cTnI) directly from whole blood, without sample pretreatments.