Recent advancement in organic fluorescent and colorimetric chemosensors for the detection of Al3+ ions: A review (2019–2024)

Abstract

Organic heterocyclic compounds are characterized by the presence of one or more heteroatoms, such as S-, N- and O-, which impart unique chemical reactivity and functionality. The presence of heteroatoms within these compounds confers several advantageous properties that render them particularly well-suited for coordination chemistry and sensing of various metal ions in complex matrices. Al3+ is pervasive in the environment and pose significant health risks, notably by interfering with iron-sulfur proteins. This interference can lead to health issues such as bone diseases, neurodegenerative disorders (e.g., Parkinson's, Alzheimer's), memory impairment, and cancer. Additionally, Al disrupts iron metabolism by affecting intestinal absorption, serum transport, and transferrin binding. Consequently, the development of sensitive and selective detection methods for Al3+ is crucial. In this review, we explore the diverse electronic and structural features of organic heterocyclic compounds. We emphasize their crucial role as ligands in coordination chemistry and their recent applications as chemosensors for detecting Al3+ ions from 2019 to 2024. Furthermore, this review also delves into the fundamental principles governing both colorimetric and fluorimetric detection methods, with a specific focus on elucidating mechanisms such as PET, ICT, ESIPT, and CN isomerization. These mechanisms play pivotal roles in the interaction between chemosensors and Al3+ ions, influencing the optical properties and resulting in detectable changes in both color and fluorescence. By elucidating the fundamental principles underlying the coordination chemistry and sensing properties of organic heterocyclic compounds, this review aims to inspire further innovation and development in the field of molecular recognition and analytical chemistry.