Recent trends in the design of chemical sensors based on graphene–metal oxide nanocomposites for the analysis of toxic species and biomolecules

Electrochemical sensors play a significant role in the industry and in everyday life. There has been a strong demand for short reaction time, and for highly sensitive, selective, responsive, stable and efficient sensors. Due to their unique electrochemical, optical and mechanical properties, graphene-based composites have enhanced the development of a new generation of sensors. The main thrust of this review is to highlight the present and future research and development work in the area of graphene/metal oxides based sensors. This review: i) discusses the latest developments in graphene–metal oxides for electrochemical sensing applications such as toxic gases and biomolecules analysis, ii) highlights the sensing mechanisms in graphene–metal oxide-based devices, architectures of sensors and performance parameters, and iii) the review concludes with a brief overview of future developments in the field of sensors. This review aims to act as a reference for researchers in developing new sensors based on graphene.