| With the rapid development of industrialization, the number of toxic pollutants released in industrial processes has increased significantly. Among them, mercury (Hg) is one of the most hazardous heavy metals. Mercury pollution is primarily transmitted through water bodies; therefore, it is one of the key pollutants monitored in environmental analysis due to its severe threat to human health. Traditional mercury ion (Hg2+) detection methods suffer from high costs, time-consuming pretreatment, and complex detection procedures. To address these issues, this paper proposes a fluorescence probe based on a hydrogel polymer-based waveguide, leveraging the turn-on mechanism of rhodamine spirolactam (Rh B-EDA). The three-dimensional network structure of the hydrogels facilitates Hg2+ penetration into the waveguide core, enables the detection of the Rh-B-EDA ring-opening turn-on reaction via propagation light confined within the waveguide, and significantly increases the adsorption surface area for Hg2+, thereby greatly reducing the detection limit. Experimental results demonstrate that the Hg2+detection limit of this hydrogel polymer waveguide sensor is approximately 1.0 × 10–13 mol/L. The waveguide sensor features a simple fabrication process, low cost, high adaptability, making it highly promising for applications in environmental monitoring. |
