Ultrasensitive and Selective Field-Effect Transistor-Based Biosensor Created by Rings of MoS₂ Nanopores

The ubiquitous field-effect transistor (FET) is widely used in modern digital integrated circuits, computers, communications, sensors, and other applications. However, reliable biological FET (bio-FET) is not available in real life due to the rigorous requirement for highly sensitive and selective bio-FET fabrication, which remains a challenging task. Here, we report an ultrasensitive and selective bio-FET created by the nanorings of molybdenum disulfide (MoS₂) nanopores inspired by nuclear pore complexes. We characterize the nanoring of MoS₂ nanopores by scanning transmission electron microscopy, Raman, and X-ray photoelectron spectroscopy spectra. After fabricating MoS₂ nanopore rings-based bio-FET, we confirm edge-selective functionalization by the gold nanoparticle tethering test and the change of electrical signal of the bio-FET. Ultrahigh sensitivity of the MoS₂ nanopore edge rings-based bio-FET (limit of detection of 1 ag/mL) and high selectivity are accomplished by effective coupling of the aptamers on the nanorings of the MoS₂ nanopore edge for cortisol detection. We believe that MoS₂ nanopore edge rings-based bio-FET would provide platforms for everyday biosensors with ultrahigh sensitivity and selectivity.