Volume 11 Issue 4 ( December 2024)

Colorimetric is a fascinating technique for the detection of heavy metal ions working based on their color formation. This review critically analyzes the latest advancements in colorimetric sensors for detecting heavy metal ions in water. It highlights the advantages of colorimetric sensors, such as their high sensitivity, selectivity, portability, and capability for on-site detection. Further, the review focuses on various materials used as matrices in the sensors. Different material-based colorimetric sensors, including agarose, paper-based, sol-gel, and polymer materials, are explored, and their unique attributes and effectiveness in sensing different heavy metals are discussed. For instance, agarose is noted for its non-toxic nature and long sensor lifetime. In contrast, paper-based sensors are commended for their ease of use and effectiveness in detecting chromium (VI) ions. The sol-gel method is recognized for its application in detecting Ni2+ ions. Meanwhile, PVC membranes are appreciated for their stability and mechanical strength. Overall, the state-of-the-art of colorimetric sensor technology is overviewed. Besides, this review underscores the importance of the colorimetric sensor in monitoring environmental pollution and protecting human health from the detrimental effects of heavy metal contamination.

Keywords: optical chemical sensor; colorimetric; heavy metals; sensor