Colorimetric and Fluorometric detection of arsenic: arsenate and arsenite

Arsenic is a highly toxic metalloid that forms different chemical states in nature, including arsenate and arsenite, as common inorganic forms. Exposure to arsenic may cause adverse effects on human health and the environment. Therefore, the detection of arsenic is critical. Exploring new approaches with low detection ranges and high sensitivity is crucial. This review paper consists of optical methods, including colorimetric and fluorometric methods, which detect arsenite and arsenate. Initially proposed colorimetric approaches such as the Gutzeit and molybdenum blue method can easily to use. However, the production of toxic substances limits their applications. Later, structurally modified molecules, nanoparticle-based assays, and their modifications are used for arsenic detection. Fluorometric methods also have noticeable attention to arsenic detection. Fluorescent approaches reported in this paper are based on semiconductor nanomaterials, other nanomaterials, and their modifications, etc. In addition, arsenate's catalytic and inhibitory activity on enzyme activity can be used to detect arsenic through colorimetric and fluorometric methods. This review highlighted the advantages, disadvantages, comparisons, and uses of colorimetric and fluorometric methods in detecting arsenite and arsenate.