Extended-Gate Indium–Tin–Zinc-Oxide Thin-Film Transistor Biosensor for Multiplexed Detection of Liver Cancer Biomarkers

Liver cancer (LC) remains one of the most prevalent and lethal malignancies worldwide. Alpha-fetoprotein (AFP) and miRNA 106a are both robust biomarkers of LC, and the multiplexed detection of these two biomarkers can significantly improve the diagnostic accuracy over single-analyte strategies. Here, we present an extended gate indium-tin-zinc-oxide (ITZO) thin-film transistor (TFT) biosensor array that enables label-free, multiplexed detection of AFP and miRNA 106a, achieving a linear dynamic range spanning nine orders of magnitude and ultralow detection limits of 83.37 ag/mL and 35.48 aM, respectively. The extended gate physically decouples the biorecognition interface from the ITZO channel, preserving high transconductance while preventing ionic and biological degradation of the biosensor, greatly enhancing the biosensor's long-term stability with >98% of its initial sensitivity remained after one month of refrigerated storage. As a consequence, clinical detection results obtained from the biosensor array platform revealed that a dual-biomarker "OR" logic achieves 100% diagnostic accuracy (AUC = 1.00) when analyzing undiluted serum from LC patients and healthy donors. Therefore, the proposed platform offers a miniaturized, low-cost alternative for early LC screening and timely therapeutic intervention.