Two-dimensional Layered MoS2 Biosensors Enable Highly Sensitive Detection of Biomolecules

Joonhyung Lee, Kyung Hee University
Piyush Dak, Purdue University
Yeonsung Lee, Kyung Hee University
Heekyeong Park, Kyung Hee University
Woong Choi, Kookmin University
Muhammad Ashraful Alam, Purdue University
Sunkook Kim, Kyung Hee University

Date of this Version



This is the Publisher PDF of Lee, J; Dok, P; Lee, Y; Park, H; Choi, W; Alam, M; and Kim, S. "Two-dimensional Layered MoS2 Biosensors Enable Highly Sensitive Detection of Biomolecules." Scientific Reports, 4, 7352. 2014. Copyright Nature Publishing Group, available at


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.


Diagnosis | Electrical and Electronics