Carbazole-Based Colorimetric and Fluorescent Chemosensors for Metal Ions Detection : A Comprehensive Review ( 2012 to till date ).

This review focuses on the development of carbazole based colorimetric and fluorescent chemosensors for the detection of metal ions including, mercury (Hg), iron (Fe), aluminium (Al) chromium (Cr) zinc (Zn), cobalt (Co) and copper (Cu) ions detection. Traditional analytical methods for detecting these metal ions, while widely used, present several draw backs such as high cost, low sensitivity, time consuming and the requirement for skilled technician. To overcome these limitations, more efficient alternatives such as colorimetric and fluorescent chemosensors have been developed. These sensors offer advantages like cost effectiveness, high sensitivity, rapid detection, and ease of use without requiring specialized technical expertise. In this review, we emphasize the applications of carbazole based colorimetric and fluorescence chemosensors. Carbazole and its derivatives are well-suited for this purpose due to their unique properties including excellent solubility, a highly conjugated structure, chemical stability, intramolecular charge transfer capabilities, and sensitivity to structural changes. These features make them ideal candidates for use as optical materials and fluorescence chemosensors in metal ion detection. The applications of carbazole- based colorimetric and fluorescent chemosensors. are summarized in tabular format for clarity.