Wang Zhen, Yi Kongyang, Lin Qiuyuan, Yang Lei, Chen Xiaosong, Chen Hui, Liu Yunqi, Wei Dacheng
State Key Laboratory of Molecular Engineering of Polymers, Fudan University, 200433, Shanghai, China.
Department of Macromolecular Science, Fudan University, 200433, Shanghai, China.
Nat Commun. 2019 Apr 4;10(1):1544. doi: 10.1038/s41467-019-09573-4.
Due to ultra-high reactivity, direct determination of free radicals, especially hydroxyl radical (•OH) with ultra-short lifetime, by field-effect transistor (FET) sensors remains a challenge, which hampers evaluating the role that free radical plays in physiological and pathological processes. Here, we develop a •OH FET sensor with a graphene channel functionalized by metal ion indicators. At the electrolyte/graphene interface, highly reactive •OH cuts the cysteamine to release the metal ions, resulting in surface charge de-doping and a current response. By this inner-cutting strategy, the •OH is selectively detected with a concentration down to 10 M. Quantitative metal ion doping enables modulation of the device sensitivity and a quasi-quantitative detection of •OH generated in aqueous solution or from living cells. Owing to its high sensitivity, selectivity, real-time label-free response, capability for quasi-quantitative detection and user-friendly portable feature, it is valuable in biological research, human health, environmental monitoring, etc.
由于自由基具有超高的反应活性，利用场效应晶体管（FET）传感器直接测定自由基，尤其是具有超短寿命的羟基自由基（•OH）仍然是一项挑战，这阻碍了评估自由基在生理和病理过程中的作用。在此，我们开发了一种具有由金属离子指示剂功能化的石墨烯通道的•OH FET传感器。在电解质/石墨烯界面处，高反应活性的•OH切断半胱胺以释放金属离子，导致表面电荷去掺杂和电流响应。通过这种内切策略，可选择性地检测浓度低至10 M的•OH。定量金属离子掺杂能够调节器件灵敏度并对水溶液或活细胞中产生的•OH进行准定量检测。由于其高灵敏度、选择性、实时无标记响应、准定量检测能力以及用户友好的便携特性，它在生物学研究、人类健康、环境监测等方面具有重要价值。
