Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY, USA.
Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, NY, USA.
Sci Adv. 2019 Nov 8;5(11):eaat9476. doi: 10.1126/sciadv.aat9476. eCollection 2019 Nov.
Measuring the behavior of redox-active molecules in space and time is crucial for understanding chemical and biological systems and for developing new technologies. Optical schemes are noninvasive and scalable, but usually have a slow response compared to electrical detection methods. Furthermore, many fluorescent molecules for redox detection degrade in brightness over long exposure times. Here, we show that the photoluminescence of "pixel" arrays of monolayer MoS can image spatial and temporal changes in redox molecule concentration. Because of the strong dependence of MoS photoluminescence on doping, changes in the local chemical potential substantially modulate the photoluminescence of MoS, with a sensitivity of 0.9 on a 5 μm × 5 μm pixel, corresponding to better than parts-per-hundred changes in redox molecule concentration down to nanomolar concentrations at 100-ms frame rates. This provides a new strategy for visualizing chemical reactions and biomolecules with a two-dimensional material screen.
测量氧化还原活性分子在空间和时间上的行为对于理解化学和生物系统以及开发新技术至关重要。光学方案是非侵入性和可扩展的，但与电检测方法相比，通常响应速度较慢。此外，许多用于氧化还原检测的荧光分子在长时间曝光下会降低亮度。在这里，我们表明，单层 MoS 的“像素”阵列的光致发光可以成像氧化还原分子浓度的空间和时间变化。由于 MoS 光致发光对掺杂的强烈依赖性，局部化学势的变化会显著调制 MoS 的光致发光，在 5μm×5μm 的像素上的灵敏度为 0.9，对于氧化还原分子浓度的变化，其灵敏度优于百分之几，浓度低至纳摩尔，帧速率为 100ms。这为使用二维材料屏幕可视化化学反应和生物分子提供了一种新策略。
