Ultra-thin two-dimensional (2D) materials have attained huge interest for biosensing applications because of their strong electrostatic coupling with target molecules such as spike proteins and DNA. One such 2D material is graphene, which is extremely thin and flexible and has a strong non-covalent interaction with the supporting constructs needed to detect biomolecules. This work aimed to develop a way to efficiently functionalize the surface of 2D material using a pyrene-based supporter construct to detect the target protein. For this purpose, high-quality, pristine graphene was grown via the chemical vapor deposition (CVD) method and transferred over the Si/SiO₂ substrate for its functionalization using our engineered pyrene–lysine-based supporter construct (PLB). The construct was synthesized using the solid-phase peptide synthesis (SPPS) method and utilized to functionalize the graphene-channel-based field-effect transistor (FET) device via non-covalent π−π stacking interaction. The optimum concentration of the functionalized PLB was evaluated via atomic force microscopy (AFM), Raman spectroscopy, and real-time electrical measurements. The characterization techniques successfully provide an overview of the effect of the concentration of PLB used for functionalization. Moreover, the performance was tested and compared in terms of the percentage response of the device generated after the detection of various concentrations of the streptavidin protein. This research could be useful in determining how to functionalize any 2D material by designing a supporter construct without material degradation and owing to over-stacking or bypassing surface screening effects.

Two-dimensional (2D) semiconductors with wide bandgap have emerged as promising materials for various applications due to their exceptional electrical, optical, and mechanical properties. In this book chapter, we provide an overview of the recent advances in the synthesis, characterization, and applications of wide bandgap 2D semiconductors. We review the structural, optical, and electronic properties, with a particular emphasis on their wide bandgap and its impact on their optoelectronic properties. Next, we discuss the potential applications of wide bandgap 2D semiconductors in various fields, including photovoltaics, biosensors, and electronic switching devices. We also highlight the challenges and opportunities associated with using these materials in practical applications, including their integration with existing technologies and the development of novel device architectures. Finally, we outline the prospects for wide bandgap 2D semiconductors, including the potential for new applications and the development of more efficient and cost-effective synthesis methods. This book chapter provides a comprehensive overview of the current state-of-the-art research on wide bandgap 2D semiconductors and their applications, highlighting the opportunities and challenges for further advancement in this exciting field. <!----> <!----> <!----> <!---->