Recently, a research team led by Professor Wenping Hu and Associate Professor Shanshan Cheng from Tianjin University reported the fabrication of an ultrasensitive and reliable platform in early cancer diagnosis, which was published online on Analytical Chemistry under the title of Ultrasensitive and Reliable Organic Field-effect Transistor-based Biosensors in Early Liver Cancer Diagnosis.

Organic field-effect transistors (OFETs) based sensors are considered as advanced biosensing platforms due to their inherent capability for multi-parameter accessibility, facile fabrication, rapid detection, and potentially low-cost application to solution processing. However, the complicated synthesis and chemical functionalization processes lead to an unpredictable decrease in OFETs performance for its further sensitive and reliable sensing applications.

Figure. Schematic representation of OFET-based biosensors. (a) Fabrication of OFET-based biosensors. (i) Au source and drain electrodes are deposited on OTS-modified SiO₂/Si substrates; (ii) PDVT-8 film is spin-coated as a charge transport layer; (iii) BFPA functional layer is modified on the device; (iv-v) AFP antibodies are immobilized to form the receptor layer for the determination of target AFP biomarkers. (b) Chemical structure of the organic molecules (BFPA and PDVT-8). (c) Schematics showing surface modification to immobilize antibodies as receptors for the determination of target AFP biomarkers.

The research team focused on the OFETs functionalization and made several key breakthroughs to create a bridge for immobilization of biological receptors through bio-conjugation chemistry. To achieve a more sensitive and reliable sensing application, they proposed a novel 2,6-bis(4-formylphenyl) anthracene (BFPA) organic material for use as the protective and functional layer of OFET-based biosensors, enabling ultrasensitive determination of alpha-fetoprotein (AFP) with femtomolar accuracy in human serum. By monitoring changes of source-drain current (I^ds) and threshold voltage (V^th) electrical signals, the device exhibits improved reliability in detecting AFP biomarkers and is able to differentiate between liver cancer patients and healthy individuals. Featuring label-free determination, shorter analysis time, and lesser sample volume, this ultrasensitive and reliable OFET-based biosensor displays numerous advantages over traditional strategies such as enzyme-linked immunosorbent assay (ELISA) and electrochemiluminescence (ECL) immunoassay, demonstrating broader clinical applications for early liver cancer diagnosis.

By Chenfang Sun from the School of Science

Editor: Eva Yin