Chromium Detection in Water Using Optical Methods: A Study of Reagent and Reagentless Approaches.

Water contaminated with chromium (Cr) poses significant risks to public health and the environment, necessitating reliable detection techniques. This review study uniquely provides a comprehensive analysis of optical methods for detecting Cr pollution in water, focusing on both reagent-based and reagentless approaches, as well as various sensing platforms. Unlike existing reviews that primarily focus on electrochemical and colorimetric/fluorimetric methods, this work highlights the untapped potential of optical technologies, such as colorimetry, SPR, UV-Vis spectroscopy, and more, in detecting distinct Cr species, including reagent and reagentless based approaches. The findings demonstrate the high sensitivity and specificity of optical methods. Reagent-based approaches offer exceptional sensitivity but involve complex preparation and potential secondary contamination. In contrast, reagentless methods, while requiring sophisticated calibration, are more environmentally friendly and simpler to implement. Future directions emphasize the development of portable, cost-effective optical devices, improved Cr species differentiation, and integration with real-time data processing and remote sensing for enhanced field monitoring. This study informs researchers and policymakers about the latest advancements in optical detection techniques and their potential to enhance water quality monitoring.