Center for Material Design Science, School of Integrated Design Engineering, Graduate School of Science and Technology, Keio University , 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan.
Anal Chem. 2017 Nov 21;89(22):12123-12130. doi: 10.1021/acs.analchem.7b02738. Epub 2017 Nov 7.
Methylmercaptan (MM) is a marker of periodontal disease; however, the required sensitivity for MM is parts per billion, which has been challenging to realize with a simple sensor. Here, we report the capability to detect MM at concentrations as low as 20 ppb using layered manganese oxide nanosheets with a quartz crystal microbalance sensor. The sensing capabilities of the manganese oxide nanosheets are promoted by adsorbed water present on and between the nanosheets. The strong adsorption of MM to the sensor, which is necessary for the high sensitivity, leads to significant hysteresis in the response on cycling due to irreversible adsorption. However, the sensor can be readily reset by heating to 80 °C, which leads to highly reproducible response to MM vapor at low concentrations. A key aspect of this sensor design is the high selectivity toward MM in comparison to other compounds such as ethanol, ammonia, acetaldehyde, acetic acid, toluene, and pyridine. This layered nanosheets design for high-sensitivity sensors, demonstrated here for dilute MM, holds significant promise for addressing needs to identify sulfur compounds associated for environmental protection and medical diagnostics.
甲硫醇（MM）是牙周病的标志物；然而，MM 的检测灵敏度需要达到十亿分之一，这对于简单的传感器来说具有挑战性。在这里，我们报告了使用具有石英晶体微天平传感器的分层氧化锰纳米片在低至 20 ppb 的浓度下检测 MM 的能力。纳米片上和纳米片之间存在的吸附水促进了氧化锰纳米片的传感能力。由于不可逆吸附，MM 对传感器的强吸附对于高灵敏度是必要的，这导致响应循环中的明显滞后。然而，通过加热至 80°C 可以很容易地重置传感器，这导致在低浓度下对 MM 蒸气具有高度可重复的响应。这种传感器设计的一个关键方面是与其他化合物（如乙醇、氨、乙醛、乙酸、甲苯和吡啶）相比，对 MM 具有高选择性。这种分层纳米片设计用于高灵敏度传感器，在此展示了对稀释 MM 的检测能力，为满足与环境保护和医学诊断相关的识别硫化合物的需求提供了重要的前景。
