Ultrasensitive Molecular Sensors Based on Real‐Time Impedance Spectroscopy in Solution‐Processed 2D Materials
Ultrasensitive Molecular Sensors Based on Real‐Time Impedance Spectroscopy in Solution‐Processed 2D Materials
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DOI：
10.1002/adfm.202106830
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发表时间：
2021-10
影响因子：
19
通讯作者：
D. Moore;A. Jawaid;Robert Busch;M. Brothers;Paige Miesle;Adam Miesle;R. Rao;Jonghoon Lee;L. Beagle;M. Motala;S. G. Wallace;J. Downing;A. Roy;C. Muratore;M. Hersam;R. Vaia;Steve S. Kim;N. Glavin
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作者：
D. Moore;A. Jawaid;Robert Busch;M. Brothers;Paige Miesle;Adam Miesle;R. Rao;Jonghoon Lee;L. Beagle;M. Motala;S. G. Wallace;J. Downing;A. Roy;C. Muratore;M. Hersam;R. Vaia;Steve S. Kim;N. Glavin
基于溶液处理的二维纳米材料的化学传感器代表了一种极具吸引力的可扩展和低成本设备。通过实时阻抗谱的实现和三元电路模型的开发，氧化还原剥落的二硫化钼纳米片对NO2气体的超灵敏经验检测限为1 ppb，外推的最终检测限接近63 ppt。这种传感器结构比传统的直流电感测方法有三个数量级的改进，因为传统的主要片间相互作用被绕过，有利于选择性地提取片内掺杂效应。同样的方法允许在聚酰亚胺衬底上使用石墨烯触点和滴铸二硫化钼纳米片的组合制造全溶液处理的柔性2D传感器，具有相似的灵敏度限制。最后，采用热退火策略来探索纳米片相互作用的可调性和随后的电路模型拟合，结果表明，在200°C的热退火下，灵敏度提高了2倍。
Chemical sensors based on solution‐processed 2D nanomaterials represent an extremely attractive approach toward scalable and low‐cost devices. Through the implementation of real‐time impedance spectroscopy and development of a three‐element circuit model, redox exfoliated MoS2 nanoflakes demonstrate an ultrasensitive empirical detection limit of NO2 gas at 1 ppb, with an extrapolated ultimate detection limit approaching 63 ppt. This sensor construct reveals a more than three orders of magnitude improvement from conventional direct current sensing approaches as the traditionally dominant interflake interactions are bypassed in favor of selectively extracting intraflake doping effects. This same approach allows for an all solution‐processed, flexible 2D sensor to be fabricated on a polyimide substrate using a combination of graphene contacts and drop‐casted MoS2 nanoflakes, exhibiting similar sensitivity limits. Finally, a thermal annealing strategy is used to explore the tunability of the nanoflake interactions and subsequent circuit model fit, with a demonstrated sensitivity improvement of 2× with thermal annealing at 200 °C.