A mini review on biosensing of Janus transition metal dichalcogenides: Fundamentals, devices, emerging applications, and future perspectives

In today's world, maintaining a healthy lifestyle requires precise control over factors such as environmental safety, food quality, disease monitoring, and clinical diagnoses. Therefore, accurate detection of biorecognition elements is essential for achieving this control. Scientific studies throughout history have shown that various traditional sensor materials such as metal oxides, noble metals, and carbon-based nanomaterials can detect biological elements using different electronic device architectures. Due to the disadvantages of traditional materials in sensing, transition metal dichalcogenides (TMDCs) have emerged as an alternative sensor material. Their ultra-thin structures and high surface-to-volume ratios make them suitable for optical, electrochemical, and field-effect transistor (FET) based biosensor device architectures. With the advancements in technology, Janus TMDC (J-TMDC) materials, a new type of material that has emerged in recent years, are highly promising in the biosensor field due to their intrinsic vertical polarization and excitonic and plasmonic coupling properties. In light of these properties, plasmonic and SERS biosensing applications have been experimentally investigated in the literature using J-TMDC type materials, but electrochemical, FET, and piezoelectric biosensor applications have remained unanswered. In this study, theoretical and experimental studies based on biosensor devices were reviewed in detail to better understand the biological element detection capabilities of J-TMDC materials. As a result, it was concluded that J-TMDC materials are quite promising in terms of detecting biological elements.