Hasan Nowzesh, Zhang Wenli, Radadia Adarsh D
Institute for Micromanufacturing, Center for Biomedical Engineering and Rehabilitation Services, Louisiana Tech University, Ruston, LA 71272, USA.
School of Biomedical Engineering, Fourth Military Medical School, Xi'an 710032, China.
Nanomaterials (Basel). 2017 Oct 21;7(10):339. doi: 10.3390/nano7100339.
This paper reports our findings on how to prepare a graphene oxide-based gas sensor for sensing fast pulses of volatile organic compounds with a better signal-to-noise ratio. We use rapid acetone pulses of varying concentrations to test the sensors. First, we compare the effect of graphene oxide deposition method (dielectrophoresis versus solvent evaporation) on the sensor's response. We find that dielectrophoresis yields films with uniform coverage and better sensor response. Second, we examine the effect of chemical reduction. Contrary to prior reports, we find that graphene oxide reduction leads to a reduction in sensor response and current noise, thus keeping the signal-to-noise ratio the same. We found that if we sonicated the sensor in acetone, we created a sensor with a few flakes of reduced graphene oxide. Such sensors provided a higher signal-to-noise ratio that could be correlated to the vapor concentration of acetone with better repeatability. Modeling shows that the sensor's response is due to one-site Langmuir adsorption or an overall single exponent process. Further, the desorption of acetone as deduced from the sensor recovery signal follows a single exponent process. Thus, we show a simple way to improve the signal-to-noise ratio in reduced graphene oxide sensors.
本文报道了我们关于如何制备基于氧化石墨烯的气体传感器以检测挥发性有机化合物快速脉冲且具有更好信噪比的研究结果。我们使用不同浓度的快速丙酮脉冲来测试传感器。首先，我们比较了氧化石墨烯沉积方法（介电泳与溶剂蒸发）对传感器响应的影响。我们发现介电泳产生的薄膜具有均匀的覆盖率和更好的传感器响应。其次，我们研究了化学还原的影响。与先前的报道相反，我们发现氧化石墨烯的还原导致传感器响应和电流噪声降低，从而使信噪比保持不变。我们发现，如果在丙酮中对传感器进行超声处理，就会得到一种带有几片还原氧化石墨烯薄片的传感器。这种传感器具有更高的信噪比，并且可以与丙酮的蒸汽浓度更好地关联，具有更好的重复性。建模表明，传感器的响应是由于单点位朗缪尔吸附或整体单指数过程。此外，从传感器恢复信号推断出的丙酮解吸遵循单指数过程。因此，我们展示了一种提高还原氧化石墨烯传感器信噪比的简单方法。
