The prostate-specific antigen (PSA) test is considered an important way for preoperative diagnosis and accurate screening of prostate cancer. Current antigen detection methods, including radioimmunoassay, enzyme-linked immunosorbent assay and microfluidic electrochemical detection, feature expensive equipment, long testing time and poor stability. Here, we propose a portable biosensor composed of electrolyte-gated amorphous indium gallium zinc oxide (a-IGZO) transistors with an extended gate, which can achieve real-time, instant PSA detection at a low operating voltage (<2 V) owing to the liquid-free ionic conductive elastomer (ICE) serving as the gate dielectric. The electric double layer (EDL) capacitance in ICE enhances the accumulation of carriers in the IGZO channel, leading to strong gate modulation, which enables the IGZO transistor to have a small subthreshold swing (<0.5 V dec⁻¹) and a high on-state current (∼4 × 10⁻⁴ A). The separate, biodegradable, and pluggable sensing pad, serving as an extended gate connected to the IGZO transistor, prevents contamination and depletion arising from direct contact with biomolecular buffers, enabling the IGZO transistor to maintain superior electronic performance for at least six months. The threshold voltage and channel current of the transistor exhibit excellent linear response to PSA molecule concentrations across five orders of magnitude ranging from 1 fg mL⁻¹ to 10 pg mL⁻¹, with a detection limit of 400 ag mL⁻¹ and a detection time of ∼5.1 s. The fabricated biosensors offer a point-of-care system for antigen detection, attesting the feasibility of the electrolyte-gated transistors in clinical screening, healthcare diagnostics and biological management.

中文翻译：

---

具有扩展栅极的电解质门控非晶 IGZO 晶体管，用于前列腺特异性抗原检测


前列腺特异性抗原（PSA）检测被认为是术前诊断和准确筛查前列腺癌的重要手段。目前的抗原检测方法包括放射免疫分析法、酶联免疫吸附分析法、微流控电化学检测法等，其设备昂贵、检测时间长、稳定性差。在这里，我们提出了一种由具有扩展栅极的电解质栅极非晶氧化铟镓锌（a-IGZO）晶体管组成的便携式生物传感器，由于用作栅极电介质的无液体离子导电弹性体（ICE）。 ICE中的双电层（EDL）电容增强了IGZO沟道中载流子的积累，从而产生强栅极调制，从而使IGZO晶体管具有较小的亚阈值摆幅（<0.5 V dec ⁻¹ ）和高通态电流（∼4 × 10 ⁻⁴ A）。独立的、可生物降解的、可插拔的传感垫作为连接到 IGZO 晶体管的扩展栅极，可防止因与生物分子缓冲器直接接触而产生的污染和耗尽，使 IGZO 晶体管能够保持卓越的电子性能至少六个月。该晶体管的阈值电压和通道电流对 PSA 分子浓度在 1 fg mL ⁻¹ 至 10 pg mL ⁻¹ 五个数量级范围内表现出出色的线性响应，并具有检测限400 ag mL ⁻¹ 检测时间为 ∼5.1 s。制造的生物传感器提供了用于抗原检测的即时护理系统，证明了电解质门控晶体管在临床筛查、医疗保健诊断和生物管理中的可行性。