Development of a Water-Soluble Fluorescent Probe Based on Natural Flavylium for Mercury(II) Ion Detection and Clinical Antidote Evaluation

A biocompatible chitosan-based nanosensor for dual-functional detection and removal of mercury ion and its application in living cells and environmental systems

Chitosan has been widely utilized due to its biodegradable, environmentally friendly, and extensive resources properties. The modification of chitosan has garnered significant attention as a promising approach for detecting and removing heavy metal contaminants. Herein, we presented a novel dual-functional fluorescent nanoprobe Nano-NAP for the effective detection and absorption of Hg2+, which could be conveniently fabricated by self-assembling a small-molecule Hg2+ fluorescent probe into a carrier of chitosan-based fluorophore (CS-MeO). The resulting Nano-NAP demonstrated commendable ratiometric fluorescent response to Hg2+ with the advantages of high selectivity, minimal interference, low detection limit (0.22 μM) and good pH stability. Given the excellent optical response, the Nano-NAP has been successfully applied in the practical measurement of Hg2+ ions in soils, seafood and actual water samples. What's more important, we have further developed a convenient and portable detection platform based on smartphone-compatible test paper strips for on-site and quantitative detection of Hg2+ levels. Furthermore, the visualization of Nano-NAP toward Hg2+ in living cells has also been accomplished, which showed the robust fluorescent imaging behavior and highlighted its broad potential in biosystem applicability. Finally, the Nano-NAP based hydrogel was made and employed as an efficient Hg2+ adsorbent in the absorption of Hg2+ in aqueous solution.

Natural and Synthetic Flavylium Derivatives: Isolation/Synthesis, Characterization and Application

Given the natural origins of flavylium derivatives, their chemical modifications, and their large potential uses in food, medicine, or green chemistry, the present review is a comprehensive study of flavylium-derived compounds. Several topics such as the green extraction and isolation techniques of flavylium derivatives including their chemical modifications and various characterization tools such as NMR, HPLC, and mass spectrometry are discussed in the review. Furthermore, the use of these derivatives in medicine, food, and materials science is presented, highlighting their relevance and the need for further investigation. Therefore, by examining the advantages and disadvantages of natural and synthetic sources, the review asserts the increased relevance of flavylium-based compounds in active molecules.

Accurate and rapid mercury susceptibility detection in aquatic samples using fluorescent probe integrated rhodamine with pyridyl isothiocyanate

Mercury, one of the various harmful metals, is particularly significant in affecting aquatic organisms, currently gaining more attentions and sparking discussions. In response to the limitations of traditional detections, fluorescent probes have emerged as a promising solution with some advantages, such as weaker background interference, shorter processing time, higher accuracy. Thus, a novel fluorescent probe, FS-Hg-1, has been developed for assessing mercury ion (Hg2+) concentrations in aquatic products. This probe displays specific recognition of mercury ions in fluorescence spectra. Notably, FS-Hg-1 exhibits a distinct color change to pink when combined with Hg2+ (with a 948-fold increase in absorption at 568 nm) and a substantial fluorescence change towards Hg2+ (361-fold increase, excitation at 562 nm, emission at 594 nm) in N, N-dimethylformamide. The probe boasts a detection limit of 0.14 μM and rapid reaction with Hg2+ within 10 s, showing an excellent linear correlation with [Hg2+] in the range of 0 to 10 μM. Through thorough analysis using FS-Hg-1, the results align with those from the standard method (P > 0.05), with spiked recovery rates ranging from 108.4% to 113.2%. With its precise recognition, low detection limit, and remarkable sensitivity, this fluorescent assay proves effective in mercury concentration determination in aquatic samples without interference. The potential of FS-Hg-1 is promising for speedy detection of residual Hg2+ and holds significance in ensuring food safety.

Imaging gastrointestinal damage due to acute mercury poisoning using a mitochondria-targeted dual near-infrared fluorescent probe

Mercury (Hg) is one of the most widespread pollutants that pose serious threats to public health and the environment. People are inevitably exposed to Hg via different routes, such as respiration, dermal contact, drinking or diet. Hg poisoning could cause gingivitis, inflammation, vomiting and diarrhea, respiratory distress or even death. Especially during the developmental stage, there is considerable harm to the brain development of young children, causing serious symptoms such as intellectual disability and motor impairments, and delayed neural development. Therefore, it's of great significance to develop a specific, quick, practical and labor-saving assay for monitoring Hg2+. Herein, a mitochondria-targeted dual (excitation 700 nm and emission 728 nm) near-infrared (NIR) fluorescent probe JZ-1 was synthesized to detect Hg2+, which is a turn-on fluorescent probe designed based on the rhodamine fluorophore thiolactone, with advantages of swift response, great selectivity, and robust anti-interference capability. Cell fluorescence imaging results showed that JZ-1 could selectively target mitochondria in HeLa cells and monitor exogenous Hg2+. More importantly, JZ-1 has been successfully used to monitor gastrointestinal damage of acute mercury poisoning in a drug-induced mouse model, which provided a great method for sensing Hg species in living subjects, as well as for prenatal diagnosis.