Lee Joonhyung, Dak Piyush, Lee Yeonsung, Park Heekyeong, Choi Woong, Alam Muhammad A, Kim Sunkook
Multi-Functional Nano/Bio Electronics Lab., Department of Electronics and Radio Engineering, Kyung Hee University, Gyeonggi 446-701, South Korea.
School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47907, USA.
Sci Rep. 2014 Dec 17;4:7352. doi: 10.1038/srep07352.
We present a MoS2 biosensor to electrically detect prostate specific antigen (PSA) in a highly sensitive and label-free manner. Unlike previous MoS2-FET-based biosensors, the device configuration of our biosensors does not require a dielectric layer such as HfO2 due to the hydrophobicity of MoS2. Such an oxide-free operation improves sensitivity and simplifies sensor design. For a quantitative and selective detection of PSA antigen, anti-PSA antibody was immobilized on the sensor surface. Then, introduction of PSA antigen, into the anti-PSA immobilized sensor surface resulted in a lable-free immunoassary format. Measured off-state current of the device showed a significant decrease as the applied PSA concentration was increased. The minimum detectable concentration of PSA is 1 pg/mL, which is several orders of magnitude below the clinical cut-off level of ~4 ng/mL. In addition, we also provide a systematic theoretical analysis of the sensor platform - including the charge state of protein at the specific pH level, and self-consistent channel transport. Taken together, the experimental demonstration and the theoretical framework provide a comprehensive description of the performance potential of dielectric-free MoS2-based biosensor technology.
我们展示了一种用于以高灵敏度和无标记方式电检测前列腺特异性抗原（PSA）的二硫化钼生物传感器。与之前基于二硫化钼场效应晶体管的生物传感器不同，由于二硫化钼的疏水性，我们的生物传感器的器件配置不需要诸如氧化铪之类的介电层。这种无氧化物操作提高了灵敏度并简化了传感器设计。为了对PSA抗原进行定量和选择性检测，将抗PSA抗体固定在传感器表面。然后，将PSA抗原引入固定有抗PSA的传感器表面，形成无标记免疫分析形式。随着所施加的PSA浓度增加，测得的器件关态电流显著下降。PSA的最低可检测浓度为1 pg/mL，比临床临界水平约4 ng/mL低几个数量级。此外，我们还对传感器平台进行了系统的理论分析，包括特定pH水平下蛋白质的电荷状态以及自洽沟道传输。综上所述，实验演示和理论框架全面描述了基于无介电层二硫化钼的生物传感器技术的性能潜力。
