A novel fluorescent probe based on naphthalimide and nile blue for selective recognition of Cu2+ and pH

A near-infrared fluorescent probe for detecting Cu2+ and its versatile applications

Copper ions (Cu2+), although essential for biological systems, pose substantial environmental and health risks at elevated concentrations. Therefore, the detection of Cu2+ in the environment is of great significance. In order to develop a simple, rapid, convenient and reliable method for Cu2+ analysis, a simple fluorescent probe was successfully prepared, which incorporates the dicyanoisophorone fluorophore and the 2-aminonicotinic acid recognition group. This probe demonstrated stable near-infrared emission at 655 nm, large Stokes shift of 235 nm, exceptional selectivity (detection limit: 0.018 μM), and robust anti-interference capabilities across diverse environments. It enabled direct Cu2+ detection in real water matrices, food (rice and mung beans), plant tissues (onion roots), and soil samples. By integrating smartphone-based chromatic analysis and portable test strips, this probe demonstrated on-site visual quantification of Cu2+ without complex instrumentation. This study provides a cost-effective Cu2+ detection solution for environmental, agricultural, and food safety applications, particularly in resource-limited settings.

Two Squaramide-Based Fluorescent Probes for Cu2+ and Cd2

The development of potential toxic metal ion probes is of great significance in the field of environmental detection. Herein, two squaramide ligands (2a, 2b) were constructed by combining the characteristics of squaric acid and imine groups. 2a and 2b can recognize Cu2+ and Cd2+, with LOD of 1.26 × 10-8 M and 2.04 × 10-8 M, respectively, and have the advantages of fast response and wide pH range. The binding ratio and binding mode of the probe and the target ion were determined by Job's plot, ESI-MS, and 1H NMR.

Application of Intelligent Response Fluorescent Probe in Breast Cancer

As one of the leading cancers threatening women's lives and health, breast cancer is challenging to treat and often irreversible in advanced cases, highlighting the critical importance of early detection and intervention. In recent years, fluorescent probe technology, a revolutionary in vivo imaging tool, has gained attention in medical research for its ability to improve tumor visualization significantly. This review focuses on recent advances in intelligent, responsive fluorescent probes, particularly in the field of breast cancer, which are divided into five categories, near-infrared responsive, fluorescein-labeled, pH-responsive, redox-dependent, and enzyme-triggered fluorescent probes, each of which has a different value for application based on its unique biological response mechanism. In addition, this review also covers the strategy of combining fluorescent probes with various anti-tumor drugs, aiming to reveal the possibility of synergistic effects between the two in breast cancer treatment and provide a solid theoretical platform for the clinical translation of fluorescent probe technology, which is expected to promote the expansion of cancer treatment technology.