Sensors for detection of Cr(VI) in water: a review

Cr(VI) present in effluent discharged from tannery, electroplating, chemical industries, etc., has led to Cr(VI)-induced environmental contamination, which is threatening the ecosystem and human health. Conventional Cr(VI)-detecting techniques are inefficient with expensive instrumentation and additional chemical compounds. To address these issues, sensors can be employed for Cr(VI) detection due to their advantages of higher selectivity, sensitivity and responsibility. This review paper firstly summarises the properties, industrial use and toxicity of Cr(VI), as well as traditional detecting techniques. Then, we describe the principles and types of electrochemical sensors (potentiometric sensors, amperometric sensors and conductometric sensors) and non-electrochemical sensors (optical sensors and microcantilever sensors) in detail for detection of Cr(VI). Challenges and examples for each of the major sensor related to different application areas are reviewed. This review paper aims to act as a reference for researchers in developing new sensors for detection of Cr(VI).