Molecular Interactions between an Enzyme and Its Inhibitor for Selective Detection of Limonene

Interface-Engineered Field-Effect Transistor Electronic Devices for Biosensing

Promising advances in molecular medicine have promoted the urgent requirement for reliable and sensitive diagnostic tools. Electronic biosensing devices based on field-effect transistors (FETs) exhibit a wide range of benefits, including rapid and label-free detection, high sensitivity, easy operation, and capability of integration, possessing significant potential for application in disease screening and health monitoring. In this perspective, the tremendous efforts and achievements in the development of high-performance FET biosensors in the past decade are summarized, with emphasis on the interface engineering of FET-based electrical platforms for biomolecule identification. First, an overview of engineering strategies for interface modulation and recognition element design is discussed in detail. For a further step, the applications of FET-based electrical devices for in vitro detection and real-time monitoring in biological systems are comprehensively reviewed. Finally, the key opportunities and challenges of FET-based electronic devices in biosensing are discussed. It is anticipated that a comprehensive understanding of interface engineering strategies in FET biosensors will inspire additional techniques for developing highly sensitive, specific, and stable FET biosensors as well as emerging designs for next-generation biosensing electronics.

Detection of Epidermal Growth Factor Receptor Expression in Breast Cancer Cell Lines Using an Ion-Sensitive Field-Effect Transistor in Combination with Enzymatic Chemical Signal Amplification

A novel strategy for epidermal growth factor receptor (EGFR) detection using a cell-based field-effect transistor (FET) with enzymatic chemical signal amplification is proposed. Four human breast cancer cell lines [BT474, MDA-MB-231 (MM231), MDA-MB-468 (MM468), and MDA-MB-453 (MM453)] were used to compare the expression levels of EGFR. The cells were non-specifically captured on the surface of the gate of the FET, irrespective of their surface antigens. With this configuration, the heterogeneity of the cells would be analyzed using secondary antibodies conjugated to different kinds of enzymes. Four breast cancer cell lines with different levels of EGFR expression were captured on the respective surfaces of the extracellular matrix (ECM) gel-coated gates of the FETs. Glucose oxidase (GOx) was conjugated to the secondary antibody, and the output signals of the cell-based FETs changed depending on the expression levels of EGFR upon addition of glucose. The order of the expression levels of EGFR among the four cell lines, determined with the cell-based FETs, was consistent with the results of fluorescence detection determined by fluorescence-activated cell sorting (FACS). The cell-based FETs are advantageous for miniaturization and in massive parallel analyses of target molecules expressed on the membranes of cells and EVs, and their small size and cost effectiveness for cancer testing could enable their realization in a future liquid biopsy.