Recently, Prof. JIANG Changlong's research team from the Institute of Solid State Physics, the Hefei Institutes of Physical Science of the Chinese Academy of Sciences developed a highly sensitive ratiometric fluorescent probe that successfully detects trivalent chromium (Cr3+) in the environment.
"This probe uses porphyrin nanoparticles formed by a block copolymer as the sensing core. The captured fluorescence color information can be converted into digital data and analyzed in real-time using a smartphone," explained Prof. Jiang.
The related research results have been published in Sensors and Actuators B: Chemical.
Chromium pollution in the environment primarily involves chromium ions in hexavalent (Cr6+) and Cr3+ forms, both of which pose serious threats to ecological systems and human health. Most existing tests focus on detecting Cr6+, often overlooking Cr3+. However, Cr3+ also significantly impacts soil, water, and the growth of plants and animals, thereby posing a threat to human health.
In this study, researchers developed a ratio fluorescence sensing system,to achieve rapid and sensitive on-site detection of Cr3+ in the environment.
The system has two main parts: Blue Carbon Dots (BCDs) as a reference and porphyrin nanoparticles (TAPP-NPs) as sensors. When Cr3+ is present, the TAPP-NPs capture it, forming a special structure. Under UV light, the TAPP-NPs stop glowing due to charge transfer in this special structure, but the BCDs keep glowing. As more Cr3+ is added, the fluorescence changes from red to blue.
Two portable sensing devices were designed to addressing different environmental requirements. which work with a smartphone app for color recognition. The app can identify the color change, convert it into digital data, and store it for analysis. This allows for quantitative detection and easy visualization of the results.
The fluorescence sensing strategy provides a new approach for real-time monitoring of Cr3+, paving the way for fast, on-site, and intuitive detection of heavy metals in the environment.
Fig1. Schematic of a portable smart sensing device based on porphyrin nanoparticles to visualize and detect Cr3+ in the environment (Image by LI Xingzhen)
