Department of Mechanical Engineering, Columbia University , New York, New York 10027, United States.
Department of Mechanical Engineering, Harbin Institute of Technology , Harbin, Heilongjiang 150001, China.
ACS Appl Mater Interfaces. 2017 Aug 23;9(33):27504-27511. doi: 10.1021/acsami.7b07684. Epub 2017 Aug 11.
This paper presents an approach to the real-time, label-free, specific, and sensitive monitoring of insulin using a graphene aptameric nanosensor. The nanosensor is configured as a field-effect transistor, whose graphene-based conducting channel is functionalized with a guanine-rich IGA3 aptamer. The negatively charged aptamer folds into a compact and stable antiparallel or parallel G-quadruplex conformation upon binding with insulin, resulting in a change in the carrier density, and hence the electrical conductance, of the graphene. The change in the electrical conductance is then measured to enable the real-time monitoring of insulin levels. Testing has shown that the nanosensor offers an estimated limit of detection down to 35 pM and is functional in Krebs-Ringer bicarbonate buffer, a standard pancreatic islet perfusion medium. These results demonstrate the potential utility of this approach in label-free monitoring of insulin and in timely prediction of accurate insulin dosage in clinical diagnostics.
本文提出了一种使用石墨烯适体纳米传感器实时、无标记、特异性和灵敏地监测胰岛素的方法。该纳米传感器被配置为场效应晶体管，其基于石墨烯的导电通道用富含鸟嘌呤的 IGA3 适体功能化。当与胰岛素结合时，带负电荷的适体折叠成紧凑稳定的反平行或平行 G-四链体构象，导致石墨烯的载流子密度发生变化，从而导致电导率发生变化。然后测量电导率的变化，以实现对胰岛素水平的实时监测。测试表明，该纳米传感器的检测限估计低至 35 pM，并且在 Krebs-Ringer 碳酸氢盐缓冲液（一种标准的胰岛灌注介质）中具有功能。这些结果表明，该方法在无标记监测胰岛素和及时预测临床诊断中准确胰岛素剂量方面具有潜在的应用价值。
