Colorimetric Sensing for Highly Sensitive Detection of Uo22+ Via Phosphorylation Functionalized Msn-Based Controlled Release System

This study had developed a simple and sensitive colorimetric sensing for the detection of UO22+, which was composed of the mesoporous silica nanoparticles functionalized with a phosphate group (MSN-PO4) and the molybdenum disulfide with a phosphate group (MoS2-PO4). In the presence of UO22+, MoS2-PO4 can be effectively adsorbed onto the surface of MSN-PO4 due to the strong affinity between the P-O bond and UO22+. The adsorbed MoS2-PO4 was then utilized as an ideal gate material to control the release of signal molecules (MB) entrapped within the pores of MSN-PO4, resulting in a detectable decrease in the absorption peak at 663 nm. This colorimetric sensing demonstrated the advantages of simplicity and easy manipulation and exhibited a linear response to the concentration of UO22+ within the range of 0.02-0.2 µM. The detection limit of UO22+ was determined to be 0.85 nM. Furthermore, the proposed colorimetric sensing has been utilized to determine UO22+ in samples of Xiangjiang River and tap water, with a high collection rate achieved. This method has displayed promising potential in preventing and controlling environmental pollution.