Turn-on fluorescence sensor based on naphthalene anhydride for Hg2+

Recent advances in fluorescent materials for mercury(ii) ion detection

Invading mercury would cause many serious health hazards such as kidney damage, genetic freak, and nerve injury to human body. Thus, developing highly efficient and convenient mercury detection methods is of great significance for environmental governance and protection of public health. Motivated by this problem, various testing technologies for detecting trace mercury in the environment, food, medicines or daily chemicals have been developed. Among them, the fluorescence sensing technology is a sensitive and efficient detection method for detecting Hg2+ ions due to its simple operation, rapid response and economic value. This review aims to discuss the recent advances in fluorescent materials for Hg2+ ion detection. We reviewed the Hg2+ sensing materials and divided them into seven categories according to the sensing mechanism: static quenching, photoinduced electron transfer, intramolecular charge transfer, aggregation-induced emission, metallophilic interaction, mercury-induced reactions and ligand-to-metal energy transfer. The challenges and prospects of fluorescent Hg2+ ion probes are briefly presented. We hope that this review can provide some new insights and guidance for the design and development of novel fluorescent Hg2+ ion probes to promote their applications.

Tb3+ luminescence cholate hydrogel-based multi-functionalized platform for Hg2+ and NO2 detection

In this paper, Tb3+ luminescence cholate hydrogel (Tb3+/hydrogel) was selected as a multi-functionalized platform, and PS-BD@Tb3+/hydrogel or PS-BS@Tb3+/hydrogel systems were fabricated respectively for selective detecting of Hg2+ in water and...

Fluorescent Sensors for Hg2+ and Cu2+ Based on Condensation Products of 4H-1,2,4 Triazole-4-Amine and Carboxylated Benzoic Acids

Mercury (Hg) causes serious health issues in its all forms. Deficiency as well as excess of copper ion (Cu²⁺) in human body is hazardous. A series of four compounds have been derived from carboxylated benzoic acids (benzoic acid, isophthalic acid, terephthalic acid and phthalic acid) and 4H-1,2,4 triazole-4-amine and characterized. Fluorescence detection of Hg²⁺ was recorded by the derivates with benzoic acid and isophthalic acid while the derivatives of terephthalic acid and phthalic acid detect Cu²⁺ by fluorescence "off" mode. Metal ions like Li⁺, Na⁺, K⁺, Zn²⁺, Al³⁺, Mg²⁺, Mn²⁺, Co²⁺, Ni²⁺, Cu²⁺, Cd²⁺, Pb²⁺ and Hg²⁺ found not to interfere. The stoichiometry of binding is 1:1 for the benzoic acid derivative with Hg²⁺ while it is 1:2 for the other three derivatives. The binding constants are ca. 10^-4.5 between the sensors and Hg²⁺ or Cu²⁺ and detection limits are around 10^-5.5 M. DFT calculation provided optimized geometries of the sensors and confirmed the stoichiometry of binding with Hg²⁺/Cu²⁺.

Dual Naked-Eye Optical Sensor Based on Imidazolium Cation and Napthalamide for Specific Detection of Fluoride

A novel naked eye fluorescence sensor (ANI) based on naphthalimide and imidazolium moieties for fluoride detection has been designed and synthesized by multiple step synthesis. The fluorescence response of ANI sensor was significantly quenched in the presence of fluoride ion upon the interaction between an acidic amide proton and acidic C2 proton (-C(2)H-) of imidazolium compound. The binding behavior of ANI and F^- ion was extensively explored by using NMR titration. Comparison of binding ability of ANI and AN sensors addressed the dominant electrostatic and hydrogen bonding interaction with F^- ion. Consequently, ANI sensor highlights a strong binding with F^- ions with a high selectivity over AN. Interestingly, ANI demonstrated a naked-eye response with colorimetric and fluorometric assay.

A naphthalene benzimidazole-based chemosensor for the colorimetric and on-off fluorescent detection of fluoride ion

A novel naphthalene benzimidazole (NBI)-based chemosensor (D2) was developed for fluoride ion (F^-) detection. The absorption spectrum of D2 changed dramatically from yellow to blue in the visible region accompanied with a 225nm red shift of its absorption maximum upon the addition of F^- in DMSO. D2 also exhibited a fluorescence turn-off response towards the fluoride ion. The emission intensity of D2 decreased drastically along the increasing F^- concentration and the detection limit for F^- was as low as 3.2×10^-9mol/L. ¹H NMR and HRMS-ESI results indicated that the formation of NBI-O^- through the desilylation reaction of F^- with NBI-OSi was responsible for the spectral changes. Overall, this kind of NBI-type molecules represent a new type chemosensor for the spectral detection of fluoride ion in solution.