All-covalently-implanted FETs with ultrahigh solvent resistibility and exceptional electrical stability, and their applications for liver cancer biomarker detection†
While tremendous progress has been made in numerous prototype high-performance field-effect transistors (FETs) during the last several decades, the inauguration of innovative FETs with ultrahigh solvent resistibility and exceptional electrical stability still remains a formidable challenge. In terms of a proof-of-concept of all-covalent FETs with both covalently-rooted source/drain electrodes and semiconductor layers, we herein report that these issues could be feasibly overcome. Taking graphene-based FETs as a paradigm, we demonstrate that the electrical characteristics of the thus-schemed all-covalently-implanted devices display negligible fluctuations even after the whole devices are immersed and ultrasonicated for 100 minutes successively in 10 kinds of common solvents (1000 minutes in total). The shelf life of the as-configured FETs reaches as long as 24 months, wherein negligible degradation could be observed even after the devices are stored for two years under ambient conditions without any protection. In virtue of these characteristics, we additionally demonstrate that our all-covalent FETs could work as high-quality biosensors of outstanding reproducibility and robustness for a label-free diagnosis of liver cancer biomarker. Our new FETs are essentially different from their traditional counterparts in that their all-covalent configuration characteristics afford them with ultrahigh solvent resistibility and exceptional electrical stability. This opens up new perspectives and a bright future for the further functionalization, integration, industrialization and commercialization of FETs, wherein multistep post-productions are inevitably encountered in practice. Beyond graphene-based FETs, our all-covalent concept might be expanded to other types of electronic materials/devices via sophisticated molecular engineering.