An aptamer-based MoS2 field-effect transistor biosensor with high sensitivity for cytokine detection

Abstract

Biosensors based on field-effect transistor (FET) are extensively utilized in biomedical engineering for their capability to achieve rapid and label-free detection of targets. However, the extremely low concentration level of biomarkers, crucial for human health, put forward higher requirements for biosensors. Developing stable and reliable biosensors with high sensitivity for biomarker detection remains challenging. In this study, we report a highly sensitive MoS₂-FET biosensor for the cytokine IFN-γ. Surface etching of the MoS₂ channel using a reactive ion etching system increases reactive sites for biological molecules on the channel surface, thereby enhancing the detection performance of the biosensor. The MoS₂-FET biosensor functionalized with aptamer demonstrates high sensitivity and selectivity for IFN-γ detection (limit of detection is 5.98 × 10⁻⁵nM). Notably, the signal responses of the MoS₂-FET biosensor are higher than that of the MoS₂-FET biosensor without Ar etching and graphene-FET biosensor. Additionally, this paper analyzes the relationship between the modification density of probe molecules and the biosensor's detection signal, establishing a theoretical foundation for further enhancing the sensor's detection performance. Experimental results confirm that the highly sensitive MoS₂-FET biosensor provides an effective testing platform for the biomarkers with low concentrations, crucial for disease prevention and early diagnosis.