Aluminum is one of the most common metals in the environment and is widely used in everyday life, from cookware and food packaging to construction and medicines. While aluminum has many useful applications, excessive exposure can be harmful to human health, potentially contributing to conditions such as Alzheimer’s disease, Parkinson’s disease, osteoporosis, and even certain cancers. It also harms plants by inhibiting root growth, which reduces agricultural productivity. Because of these risks, it is important to have reliable, simple, and affordable tools for detecting aluminum contamination in water and other environments. In this study, researchers developed a new fluorescent sensor called BRTDA, based on a bis(rhodamine) structure. The sensor has a unique feature: in normal conditions it is colorless and does not emit light, but when it encounters aluminum ions (Al³⁺), it quickly changes color to bright pink and produces a strong fluorescent signal. This “turn-on” behavior makes it easy to see and measure the presence of aluminum, even in very small amounts. To understand how this works at the molecular level, the team used advanced computer modeling known as density functional theory (DFT). These calculations showed that when BRTDA binds to aluminum, the molecule undergoes a structural twist and opens up, which changes its electronic properties and causes the strong fluorescence. The sensor was able to detect aluminum at extremely low concentrations—down to 76 nanomolar (around 2 parts per billion). Importantly, it also worked successfully in real-world tests, detecting aluminum in tap water and mineral water with high accuracy. This new sensor provides a promising, low-cost, and highly sensitive method for monitoring aluminum pollution. It has potential applications in environmental monitoring, public health protection, and even agricultural management, offering a valuable tool to reduce risks from aluminum contamination. Reference: M. Promkatkaew, W. Sakulsaknimitr, K. Rakdee, P. Thanabunrit, S. Chomngam, P. Kongsaeree, P. Srisuratsiri. Novel bis(rhodamine)-based fluorescence sensor for highly selective detection of Al(III): DFT mechanistic studies and analysis in real samples. J. Mol. Struct. (2026) 1349, 143681. https://doi.org/10.1016/j.molstruc.2025.14368
