题目: Stable rhodamine lactam probe enabled by intramolecular H-bond for sensitive nitrite detection and mechanism study

作者: Yaqin Wang (王雅琴，2023 级本科生), Min Li, Wei Fan, Yi Zhang* (张亿), Sean Xiao-an Zhang* (张晓安)

单位: Key Laboratory of Green and Precise Synthetic Chemistry and Applications, Ministry of Education; School of Chemistry and Chemical Engineering, Huaibei Normal University, Huaibei, Anhui 235000, P. R. China; State Key Lab of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, P. R. China

摘要: Accurate detection of nitrite is crucial for human health and ecological safety, while traditional fluorescent probes suffer from poor stability and easy failure under acidic conditions. Herein, a modified rhodamine lactam probe Rh-3N was successfully synthesized by the research team. Through intramolecular hydrogen bond construction and site-specific modification at the 3′ position, the probe achieves excellent stability across a wide pH range (0-14) and high temperature (up to 85 ℃). The probe exhibits high selectivity and sensitivity toward nitrite, with detection limits of 4.4 nM (fluorescence) and 5.3 nM (absorption), which are significantly lower than the maximum contaminant level set by the U.S. EPA. Additionally, an oxalic acid-coated test strip based on Rh-3N was developed, realizing visual detection of nitrite with a limit of 0.5 ppm and maintaining reliable performance for over six months. Mechanistic studies confirm that the amino group enables the formation of a diazonium salt intermediate with nitrite, triggering specific lactam ring-opening. This work provides a new tool for rapid nitrite detection in food safety and environmental monitoring, and offers innovative insights for the design of high-performance fluorescent probes.

影响因子: 4.7

分区情况: SCI 二区

链接: https://doi.org/10.1016/j.molstruc.2025.144347

年、卷、页: 2026, 1351: 144347

（文：张亿 / 审核：刘理华 / 审校：孟令国 / 终审：赵娟 ）