Electrochemical Aptasensor Based on Topological Material Bi₂Se₃ Sheets for Sensitive Detection of Interferon-γ

Interferon-gamma (IFN-γ), an essential inflammatory cytokine, is intricately associated with a variety of fatal diseases as a key early biomarker. In this work, we designed and constructed an electrochemical aptasensor based on topological insulator Bi₂Se₃ sheets. Micron-scale Bi₂Se₃ sheets were prepared by electrochemical exfoliation from single crystals to make electrodes of the aptasensors. The unique and robust Dirac surface states of Bi₂Se₃ could enhance the charge transfer efficiency of the solid-liquid interface, improving the performance of the aptasensors. The developed aptasensor exhibits a linear response to IFN-γ concentration in the range of 1-100 pg/mL with a detection limit as low as 0.6 pg/mL, enabling it to meet the clinical requirements. The performance of the aptasensors also shows excellent stability and selectivity. Furthermore, the aptasensor was applied to human serum detection and was comparable in performance to the clinical standard enzyme-linked immunosorbent assay technique. Our work indicates that the aptasensor based on Bi₂Se₃ sheets has great potential for application in the clinical detection of IFN-γ and other possible biomarkers.