2D materials for bio- and chemical- sensing applications

Graphene and graphene-like two dimensional (2D) materials, such as transition metal dichalcogenides (TMDs), hexagonal boron nitride (h-BN), and transition metal oxides (TMOs), have attracted great attention for a wide variety of biosensing technologies in recent years. 2D materials provide an extremely high density of active surface sites over a large area, making them ideal for biochemical sensing applications. What makes 2D layered materials even more fascinating is their exotic electrical and optical properties compared to their bulk form. Electrically, the 2D material family ranges from metallic (e.g., graphene) to semiconducting (e.g., MoS2, WS2, MoTe2) to insulating (e.g., h-BN). Optically, they also experience a broad range of properties, for example, fluorescence quenching or emitting, plasmonic nanostructure enhanced emission, defect-related emission and so on. With the help of surface chemistry, 2D materials can be engineered to respond to specific analytes with extremely high sensitivity.

So far, bio- and chemical- sensors are based on either optical or electrochemical signals. A multimodal sensor, which combines both the electrochemical and optical detection, is desirable in many ways including to improve the sensitivity and specificity, and to demonstrate multifunctionality. 2D materials may provide an ideal solution. In this project, we will develop such multimodal sensors using 2D layered materials in an LED or a light-emitting field-effect transistor configuration, integrated with microfluidic channels for surface functionalisation and analyte delivery, as well as a CMOS compatible silicon photodetector array for optical signal detection, in order to investigate biological and chemical reactions, such as proteins binding, enzymes actions and so on.