Farid Ahmed, Muhammad Muzammal Hussain, Linyu Zeng, Qiyu Lei, and Hai Xiong*

OnMarch 29th, Prof. Xiong groupfrom the Institute for Advanced Studies at Shenzhen University published aresearchpaper titled “Performance Improvement for Colorimetric Detection of Chromium and Catalytic Degradation of Environmental Pollutants by Synergistic Citrazinic Acid-Functionalized AgNPs”onMicrochemical Journal(https://www.sciencedirect.com/science/article/pii/S0026265X25008720).Prof. Hai Xiong is theonlycorresponding author, andDr.Farid Ahmedis the first author. Institute for Advanced Study of Shenzhen University is theonlyaffiliation.

The detection and removal of environmentally toxic analytes have garnered significant attention due to their numerous harmful effects on human health. In this study, the synthesized citrazinic acid-coated silver nanoparticles (CZA-AgNPs) were found to be highly stable over a wide spectrum of physiological conditions (such as pH, temperature, and high electrolyte concentrations), and TEM and SEM analysis demonstrate that the average size of CZA-AgNPs was around 40 nm with spherical morphology. In the presence of other competitive metal ions, the metal ion recognition potential of CZA-AgNPs exhibited exceptional selectivity for Cr³⁺recognition without interference, and a LOD of 6.24 nM is more sensitive than the previously reported methods. The addition of Cr³⁺ions upon CZA-AgNPs resulted in a discernible color change from their pale-yellow to a vibrant pink hue (naked eye visualization), along with the appearance of a new absorption band about 580 nm revealing the formation of the new complex (colorimetric probe). The CZA-AgNPs possess good cooperative binding with Cr³⁺, 4-nitrophenol, or methylene blue, which is demonstrated as“one stone, three birds”in sensitive detection of Cr³⁺ions and effective reuseable catalyst for environmental pollutants, thereby holding significant implications for environmental monitoring and public health initiatives.

Figure 1.Schematic representation of the catalytic hydrogenation mechanism for the reduction of 4-NP and MB using NaBH₄, facilitated by CZA-AgNPs-basednano catalyst.