Fluorescent Chemodosimeter For Hg2 Research Articles

A facile and highly selective “turn-on” fluorescent chemodosimeter for Hg2+ and its AIE activity

An aggregation-induced emission (AIE) active anthracene-based fluorescent chemodosimeter, anthracene-9-carbaldehyde hydrazone (ACH), was synthesized via a facile one-step reaction from anthracene-9-carbaldehyde (AC) and hydrazine monohydrate. The structure of probe ACH was completely characterized by a variety of methods, including MS, 1H NMR, 13C NMR, FT-IR, and elemental analysis. The probe ACH showed high specificity and excellent sensitivity for Hg2+ in MeOH-water (9/1, v/v) solution, which exhibited an obvious fluorescence “turn-on” change with a mega Stokes shift of 157 nm (λEx = 256 nm, λEm = 413 nm) and a low detection limit of 5.67 × 10−8 M. Studies of the sensing mechanism indicated that the fluorescence “turn-on” response was presumably owing to the Hg2+-promoted hydrolysis reaction of ACH to provide the intensely fluorescent AC. It was worth noting that the reaction-based probe could be successfully used to detect the concentration of Hg2+ in real water samples and distinguish Hg2+ on the filter papers and TLC plates. We expect this work can stimulate the emergence of preferable fluorescent chemodosimeter for practical application.

A fluorescent and colorimetric probe enables simultaneous differential detection of Hg2+ and Cu2+ by two different mechanisms

A new Schiff-base fluorescence probe CS containing benzimidazole and coumarin fluorophores was synthesized and characterized by NMR, IR and ESI-MS. Fluorescence and absorption spectra show the unique changes in the presence of Hg2+ and Cu2+. Hg2+ induces a remarkable fluorescence enhancement and results in mercury-promoted hydrolysis of a mercury-CS complex to convert the imine group to the aldehyde group. Cu2+ leads to a colorimetric change from colorless to pale yellow and causes formation of a copper-CS complex. Thus, CS can act as a fluorescent chemodosimeter for Hg2+ and a naked-eye chemosensor Cu2+. The cell imaging experiments for Hg2+ show a slow enhancement of a bright blue fluorescence with increasing incubation time, while Cu2+ instantly quenches the fluorescence and then the fluorescence intensity has no further change by extending the incubation time. Therefore, the probe CS shows its potential application for simultaneous differential detection of Hg2+ and Cu2+ in living cells based on the fluorescence response time.

A new fluorescent chemodosimeter for Hg2+-selective detection in aqueous solution based on Hg2+-promoted hydrolysis of rhodamine-glyoxylic acid conjugate

A novel fluorescent probe (RBHA) for Hg2+ was facilely synthesized by one-step condensation between rhodamine B hydrazide and glyoxylic acid. The probe could selectively detect Hg2+ in a near pure aqueous condition with a broad pH region of 5–10. A good linear relationship between the fluorescence intensity and the Hg2+ concentration was found in the range of 5.0–200μM (R2=0.9825) with a detection limit of 1.0μM (S/N=3). Based on MALDI-TOF-MS analysis, a sensing mechanism of Hg2+-promoted hydrolysis of rhodamine-glyoxylic acid conjugate was proposed. This probe was applied for detection of Hg2+ in tap water samples with satisfying results and fluorescence imaging in living cells.

A Fluorescent Chemodosimeter for Hg2+Based on a Spirolactam Ring-Opening Strategy and its Application Towards Mercury Determination in Aqueous and Cellular Media

A novel fluorescent chemosensor rhodamine B phenyl hydrazide (RBPH) for Hg(2+) was designed and synthesized. This probe is highly sensitive, selective, and irreversible for Hg(2+) and exhibits fluorescent response at 580 nm. RBPH also displayed detectable color change from colorless to pink upon treatment with Hg(2+). This property has been utilized as naked eye detection for Hg(2+) in various industrial samples. Fluorescence microscopic experiments demonstrated that this chemosensor is cell permeable and can be used for fluorescence imaging of Hg(2+) in cellular media. This probe can detect Hg(2+) with good linear relationships from 1 to 100 nM with r = 0.99983 and the limit of detection were found to be 0.019 nM with ± 0.91 % RSD at 10 nM concentrations.

A highly selective off–on fluorescent chemodosimeter for Hg2+ based on a anthracene–bis(phosphinesulfide) conjugate

A chemodosimeter Ph2P(S)NP(–S–CH2–anthracene)Ph2 (L1), featuring the methylanthracenyl moiety covalently linked to one of the two S atoms of an S,S′-tetraphenyldithioimidodiphosphinate (L) unit exhibited good selectivity and sensitivity for Hg2+ in an aqueous environment. The chemical reaction involved differs from those reported in the literature for other Hg2+ chemodosimeters: the binding of Hg2+ induces the cleavage of the PS–CH2 bond to form the stable neutral complex [HgL2] and an emissive anthracenyl derivative. The X-ray crystal structure of L1 is reported (CCDC number 919620).

A selective and sensitive “turn-on” fluorescent chemodosimeter for Hg2+ in aqueous media via Hg2+ promoted facile desulfurization–lactonization reaction

A novel highly selective and sensitive "turn-on" fluorescent chemodosimeter for Hg(2+) in pure aqueous media has been developed.