Smart Organic Probes and Their Applications: Sequential Fluorometric and Colorimetric Sensing of Cu2+ and CN- Ions: A Review (2018-2025)

Abstract

The detection of Cu²⁺ and CN^- ions is of significant importance due to their crucial roles in biological and environmental systems. While CN^- is widely utilized in industrial applications, its high toxicity poses severe risks to human health and the environment, necessitating precise monitoring. Similarly, Cu²⁺, an essential trace element, becomes hazardous at excessive concentrations, leading to liver damage, cardiovascular diseases, and ecological toxicity. Dual-channel sensors that employ both colorimetric and fluorometric responses have gained attention for their ability to detect multiple analytes simultaneously with high specificity, cost-effectiveness, and operational simplicity. This review highlights recent advancements (2018-2025) in smart organic probes for sequential fluorometric and colorimetric sensing of Cu²⁺ and CN^- ions. Various sensing mechanisms, including deprotonation, coordination, and addition reactions, have been explored to achieve selective recognition. The challenges associated with interference from other metal ions, solubility issues, and real-world applicability are critically analyzed. The development of multi-target sensors is emphasized, showing their potential for real-time environmental monitoring, medical diagnostics, and industrial safety applications. Future perspectives focus on improving probe performance through structural modifications, enhancing water solubility, and integrating smart materials for portable sensing platforms.

Keywords: Colorimetric; environmental monitoring; liver damage; organic probes; toxicity.