A review on photochemical sensors for lithium ion detection: relationship between the structure and performance

Abstract

The application of lithium in portable electronic devices, medical field, catalysts, and so on has increased in recent years because of the unique properties of lithium. Therefore, detection and sensing of lithium ions are very important in chemical, environmental and biological processes. Sensors as high-rate detecting tools have been widely used for the detection of lithium ions under a variety of conditions. Among different kinds of sensors, photochemical sensors with easy control capabilities have been used as smart systems with rapid response to light as a physical stimulus. Photochemical sensors have attracted much attention due to their advantages such as real-time, fast, cost-effective, and optical detection. Photochromic and fluorescent compounds in contact with the stimulus, with changes in optical properties such as color or fluorescence intensity, can be used as optical sensors with a high detection speed and accuracy. Many fluorescent compounds have been used to prepare photochemical sensors of lithium such as spiropyran, nitrobenzoxazole, coumarin, porphyrin, etc. Herein, we provide an overview of the mechanisms of lithium ion adsorption and desorption by these optical sensors. We have discussed the performance of photochemical sensors considering their structural properties. Moreover, the issue of lithium ion storage is highlighted according to the chemical structure of the probes.