Organic Field-Effect Transistor-Based Biosensors with Enhanced Sensitivity and Reliability under Illumination for Carcinoembryonic Antigen Bioassay

Abstract

Achieving biosensors of high sensitivity and reliability is extremely significant for early diagnosis and treatment of tumor diseases. Herein, a novel organic field-effect transistor (OFET)-based biosensor was developed and applied for carcinoembryonic antigen (CEA) bioassay. This OFET-based biosensor can respond sensitively to the antigen−antibody immune-recognition reaction under illumination and darkness, respectively, thereby generating electrical signal changes of source-drain current (I DS ) and threshold voltage (V th ). The OFET-based biosensor exhibits detection limits for CEA detection of 0.5 and 0.2 pM, respectively, using I DS and V th as the response signals under darkness. When a specific intensity of light is applied, light will influence the charge-carrier transport process in the conductive channel, thus causing biosignals to turn into higher electrical signal changes of photocurrent and threshold voltage under illumination. Compared with the detection results in the dark, the biosensor exhibits higher sensitivity for CEA detection under illumination with detection limits of 13.5 and 16.9 fM. Also, multisignal outputs effectively improve the reliability of the biosensor for CEA detection. Consequently, with powerful detection functions, this OFET-based biosensor is expected to become a high-performance biosensing platform for the detection of various biological substances in the future.

Carbon Nanotube Field-Effect Transistor Biosensor with an Enlarged Gate Area for Ultra-Sensitive Detection of a Lung Cancer Biomarker

“…We characterized the immobilization of antibodies and binding of antibody-antigen using AFM and electrical measurements (Figure S8). AFM height images (Figure S8a,b) show that, with the addition of the anti-CEA, the surface height increased from 4.48 to 15.2 nm, increasing 10.72 nm, which was consistent with the results in the literature . The root-mean-square roughness of the channel region increases significantly from 1.60 to 5.02 nm.…”

“…AFM height images (Figure S8a,b) show that, with the addition of the anti-CEA, the surface height increased from 4.48 to 15.2 nm, increasing 10.72 nm, which was consistent with the results in the literature. 25 The root-mean-square roughness of the channel region increases significantly from 1.60 to 5.02 nm. In summary, the CNT-FET biosensor has successfully constructed a specific identification platform to ensure the effectiveness of the CEA detection process.…”

“…FET-based biosensors are emerging detection technologies with inherent advantages, such as high sensitivity, − quick response, label-free operation, , and scale integration . Through electrostatic coupling between charged biomolecular and semiconductor channels, the concentration information of target biomolecules can be detected with high sensitivity and transmitted in readable electrical signals.…”

Recent progress of biosensors for the detection of lung cancer markers

“…10 FET sensors detect different proteins. (A) Development of OFET-based biosensors for the CEA assay under illumination and darkness, 182 Copyright 2021 American Chemical Society. (B) Schematic illustration of the sequential process for MMP-9 detection, 127 Copyright 2019 American Chemical Society.…”

“…The materials of the FET for detecting the antigen and antibody mainly include silicon nanomaterials, graphene, 181 molybdenum dioxide 127 and organics. 182 Graphene-based peptide sensors can be used as prognostic indicators for early cancer. 183 Different silicon nanomaterials were used to detect the CEA, namely nanobelt silicon, 126 nanotubes, 184,185 silicon nanowires, 186 etc.…”