Electrochemical Sensors Based on Carbon Allotrope Graphene: A Review on Their Environmental Applications

Abstract

Anthropogenic activity in terms of urbanization, industrialization, and modern agricultural techniques challenges the natural environment in terms of compromise in air pollution and water quality, which lead to hazardous health impacts on human beings. In this context, it is very essential to monitor the air and water quality to a maximum possible extent with maximum accuracy, which is of utmost significance. A significant effect on human health due to pollutants makes their detection in water and air essential. Even though various techniques of monitoring these pollutants are available, proven advantages of electrochemical techniques at-tract more attention. Because of this, an attempt is made to review some of the latest advances in electrochemical sensing of environmental con-taminants, which include heavy-metal ions and pesticides. Electrochemical sensing has been done by using sensors designed with various materials. However, sensors designed with carbon and its allotropes such as carbon nanotubes, graphene derivatives, carbon nanodots, active carbon, screen-printed carbon electrode, and others are reviewed. Even though these sensors are capable of being used in medical analysis, food safety, soil quali-ty, drug detection, etc., the review paper highlights only applications related to environmental monitoring. This review is mainly meant to come up with an understanding of the present-day progress in electrochemical applications based on carbon and its allied materials towards environmental pollutants. This review highlights some of the synthesis techniques of graphene (an allotrope of carbon) and sensor designing along with their performance. This review has established the compatibility in the pub-lished literature that graphene and related materials play a significant role in electrochemical sensing of pollutants.