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Sensing of gaseous environment pollutants and health hazards is in demand these days and in this regard, lethal phosgene has emerged as a leading entrant. In this contribution, we have successfully developed a facile chemodosimeter (ANO) based on an anthracene fluorophore and oxime recognition site with an interesting mechanism to sense lethal phosgene evolved from bleaching powder, a very popular disinfectant and sanitizer. The ANO probe is highly competent in recognizing deadly phosgene in solution and in the gaseous phase with a detection limit in the nanomolar range (1.52 nM). The sensing mechanism is confirmed by UV-vis, emission spectroscopy, mass spectrometry, and computational studies. [ABSTRACT FROM AUTHOR]

A simple and potent chemosensor AFL has been successfully developed to recognize Sn2+ selectively in marine algae or, more precisely, seaweed, as they are at huge risk from marine contamination. The bioaccumulation of Sn2+, mainly by the algae community, poses a great threat to the entire environment as Sn2+ toxicity flows towards higher organisms through food chain. The chemosensor AFL shows high selectivity and sensitivity towards Sn2+ with an extremely low detection limit, i.e. 90 nM, and demonstrates turn-on fluorescence with a bright cyan blue colour. The interaction mechanism is well supported by absorption, fluorescence titration, NMR titration and mass spectrometry, as well as theoretical analysis. Moreover, tin accumulation in green algae has also been revealed efficiently through confocal microscopic imaging. The quantification studies demonstrate that the AFL probe can be used as a proficient fluorescent marker for detecting Sn2+ in aquatic plants to save the marine ecosystem. [ABSTRACT FROM AUTHOR]

In recent years the excessive use of hydazine containing chemical pesticides and insecticides in farming practices is well pronounced, which directly or indirectly impart a great threat towards the total environment. Considering the above fact we are motivated to introduce a new, efficient and simple chemodosimeter (NCD) based on a carbazole-naphthalimide framework to recognize and estimate the mutagenic hydrazine within several affected cropland flowers. Probe NCD can detect hydrazine in a nanomolar range (65 nM or 2 ppb) in the presence of other metal ions, anions and amines, which gives it not only great potential but also makes it selective and sensitive. The sensing mechanism is confirmed by UV-vis, emission, and mass spectroscopy, and computational studies. We have successfully characterized probe NCD by 1H and 13C NMR and mass spectrometry as well as by single crystal analysis. [ABSTRACT FROM AUTHOR]

A naphthaldehyde-pyridoxal conjugated chemodosimeter (NPLC) was developed and employed for the sensitive and selective detection and estimation of cyanide in common water hyacinth (Eichhornia crassipes), a free floating macrophyte used in the phytoremediation process since ancient times. The non-fluorescent nature of the probe NPLC, directed by the possibility of excited state intramolecular proton transfer process (ESIPT), was promptly changed due to CN− induced di-deprotonation of the probe. The naked eye color change and turn on vivid fluorescent color of NPLC was attributed to the inhibition of the ESIPT mechanism in the deprotonated NPLC (NPLC-D). The selective detection of cyanide ion in the nanomolar range (81 nM), among other interfering anions, makes it exclusive. The involvement of the probe in a chemodosimetric fashion toward cyanide was elucidated by experimental and computational studies. [ABSTRACT FROM AUTHOR]

A new fluorescent chemosensor (NAN), fabricated by integrating 2-hydroxy naphthaldehyde and 1,8-naphthalic anhydride, shows high affinity for aluminium over other bio-relevant metal ions. The probe solution rapidly switched from non-fluorescent to bright blue fluorescence upon the addition of Al 3+ under a UV-lamp, possessing a remarkably low detection limit of 33 nM. The interaction mechanism between the metal ion and NAN has been well established by a number of techniques such as absorbance, fluorescence, and 1 H NMR titration and verified by detailed theoretical calculations as well. To show the practical efficacy of our synthesized probe NAN we have employed it to recognize Al 3+ only by using a simple paper strip and estimate the concentration of Al 3+ ions in various pharmaceutical drugs and supplements as they are some of the major sources of aluminium accumulation in the human body resulting in various neurodegenerative disorders, especially Alzheimer's disease.

An innovative fluorescein appended naphthalene diimide based probe (FANDI) has been prepared and characterized to selectively recognize hypochlorite or ClO - ions in the presence of other reactive oxygen species (ROS) and biorelevant ions, using a unique chemodosimetric method. Hypochlorite induced oxidation can efficiently alter the initial photophysical properties of FANDI and shows an easily detectable "turn on" green fluorescence. The chemodosimeter FANDI can efficiently detect exogenous as well as endogenous ClO - ions in RAW 264.7 cells (macrophages) and zebrafish embryos (Danio rerio) which further ensures the high potential, easy cell permeability and photostability of FANDI and makes it worth exploring in the future.