Meng Xingyu, Yi Zhenkai, Liu Xuanxuan, Wu Yaoyao, Fang Chuyao, Ge Zhaolin, He Yifei, Li Sina, Xie Xi, Zhang Limei, Xie Zhuang
School of Materials Science and Engineering and Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Sun Yat-sen University, Guangzhou, 510275, PR China.
State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, Guangdong Province Key Laboratory of Display Material and Technology, Sun Yat-Sen University, Guangzhou, 510006, PR China.
Biosens Bioelectron. 2025 Apr 1;273:117170. doi: 10.1016/j.bios.2025.117170. Epub 2025 Jan 13.
Point-of-care testing (POCT) of trace amount of biomarkers in biofluids is critical towards health monitoring and early diagnosis. In particular, to facilitate non-invasive saliva testing, the development of low-cost, lightweight and disposable biosensors is in urgent need, while the ultrahigh sensitivity beyond conventional clinical tests remains a great challenge. Herein, we demonstrate a simple and fully printable all-polymer organic electrochemical transistor (OECT) biosensor to detect femtomolar (fM)-level biomolecules in saliva within a few minutes by employing highly conducting lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)-doped poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) serving as both the channel and gate. A 3D microtip-shaped and Au nanoparticle-decorated multiscale gate interface facilitates the sub-fM-level sensing of female hormones (e.g., progesterone) and oligonucleotide cancer biomarkers by aptamers and DNA probes, respectively. Compared to a planar gate, the micro-engineered interface endows the OECT biosensor with significantly lower detection limit by 10-100 times down to <0.1 fM and faster response of <5 min, accomplishing unprecedentedly high sensitivity while maintaining outstanding mechanical flexibility. Consequently, such microtip-gate all-polymer OECT (MAOECT) enables POCT directly in 1000-fold diluted human saliva samples without centrifugation or redox probes, benefiting female fertility monitoring and oral cancer diagnosis as proof-of-concept demonstrations. This straightforward approach presents great potentials in low-cost wearable health management, at-home monitoring and personalized medicine.
生物流体中痕量生物标志物的即时检测（POCT）对于健康监测和早期诊断至关重要。特别是，为了促进非侵入性唾液检测，迫切需要开发低成本、轻便且一次性使用的生物传感器，而超越传统临床试验的超高灵敏度仍然是一个巨大的挑战。在此，我们展示了一种简单且完全可印刷的全聚合物有机电化学晶体管（OECT）生物传感器，通过使用高导电性的双（三氟甲磺酰）亚胺锂（LiTFSI）掺杂的聚（3,4 - 乙撑二氧噻吩）：聚（4 - 苯乙烯磺酸盐）（PEDOT:PSS）作为通道和栅极，在几分钟内检测唾液中飞摩尔（fM）水平的生物分子。一个三维微尖形状且装饰有金纳米颗粒的多尺度栅极界面分别促进了适体和DNA探针对女性激素（如孕酮）和寡核苷酸癌症生物标志物的亚fM水平传感。与平面栅极相比，微工程界面使OECT生物传感器的检测限显著降低10 - 100倍，低至<0.1 fM，响应速度更快，<5分钟，在保持出色机械柔韧性的同时实现了前所未有的高灵敏度。因此，这种微尖栅极全聚合物OECT（MAOECT）能够直接在未经离心或氧化还原探针处理的1000倍稀释人唾液样本中进行POCT，作为概念验证演示，有利于女性生育力监测和口腔癌诊断。这种直接的方法在低成本可穿戴健康管理、家庭监测和个性化医疗方面具有巨大潜力。
