Unsymmetrical azine Schiff base 5-diethylamino-2-[(4-diethylamino- benzylidene)-hydrazonomethyl]-phenol (receptor 1) having multiple binding sites (-NEt2 and -OH group) have been synthesized. The receptor 1 exhibits color change from light yellow to purple and bright yellow in presence of Cu2+ ion and Fe3+ ion, respectively which is detectable by naked-eye. But it shows red color in presence of mixture of all metal ions. The UV-vis spectral investigation of receptor 1 shows a remarkable spectral shift from 410 nm to 527, 572 and 620 nm in presence of Cu2+ ion and 485 nm in presence of Fe3+ ion in acetonitrile solvent. Interestingly, Cu2+ ions generates a new charge transfer emission band at 532 nm in the expense of local emission of receptor at 480 nm, but Fe3+ ion only quenched the local emission. The spectral response of receptor is almost insignificant in presence of other metal ions (Mn2+, Zn2+, Co2+, Ni2+, Cd2+, Hg2+, Li + and Na+ ions). © 2011 Elsevier B.V. All rights reserved.

NIKHIL GUCHHAIT

Chemistry

S DALAPATI

S JANA

M A ALAM

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Sensors and Actuators, B: Chemical

We report the synthesis of a novel hydrazine based compound 1-[(2-Hydroxy-1, 2-diphenyl-ethyl)-hydrazonomethyl]-naphthalen-2-ol (2). Compound 2 is the first report of its kind. We utilized the aforesaid compound to detect Cu2+ and F− via emission enhancement and naked eye color change. The structural intricacies of 2 have been explored by its crytal structure. The mechanism of binding of 2 with F− has been established by 1H NMR titration. The limit of detection for Cu2+ and F− is ∼9.0 × 10−7 (M) and 1.0 × 10−6 (M), respectively. The practical performance of 2 is demonstrated by successful live cell imaging of Cu2+ and detection of F− in toothpaste. © 2017 Elsevier B.V.

Journal of Photochemistry and Photobiology A: Chemistry

Hydrazine appended self assembled benzoin-naphthalene conjugate as an efficient dual channel probe for Cu2+ and Fâˆ’: A spectroscopic investigation with live cell imaging for Cu2+ and practical performance for fluoride

Two amido-schiff bases (3-Hydroxy-naphthalene-2-carboxylic acid pyren-1-ylmethylene-hydrazide and Naphthalene-2-carboxylic acid pyren-1-ylmethylene-hydrazide) have been synthesized having a common structural unit and only differs by a –OH group in the naphthalene ring. Both of them can detect Cu 2 + ion selectively in semi-aqueous medium in distinctly different output modes (one detects Cu 2 + by naked-eye color change where as the other detects Cu 2 + by fluorescence enhancement). The difference in the binding of Cu 2 + with the compounds is the reason for this observation. The detection limit is found to be micromolar region for compound which contains –OH group whereas the compound without –OH group detects copper in nano-molar region. DFT calculations have been performed in order to demonstrate the structure of the compounds and their copper complexes. Practical utility has been explored by successful paper strip response of both the compounds. The biological applications have been evaluated in RAW 264.7. © 2017 Elsevier B.V.

Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy

Binding mode dependent signaling for the detection of Cu 2 + : An experimental and theoretical approach with practical applications

We report the synthesis of a novel compound (E)-bis-N′-((1H-pyrrol-2-yl)methylene)-pyridine-2,6-carbohydrazide and its sensing ability to detect copper(ii) ion in aqueous medium by a sharp color change from yellow to brown, the sensing limit being 4.0 × 10-9 M. Theoretical modeling of the compound and its copper complex was performed. Practical utility was explored by successful paper strip response. © The Royal Society of Chemistry 2016.

RSC Advances

Highly sensitive and selective "naked eye" sensing of Cu(ii) by a novel amido-imine based receptor: A spectrophotometric and DFT study with practical application

The sensor HNHCB (3-hydroxy-naphthalene-2-carboxylic acid (4-cyano-benzylidene)-hydrazide) comprises a -CONH- group, -OH group, -CHN- linkage and an electron withdrawing -CN group that can act as both an anion (fluoride) and a cation (copper) sensor by two distinct output modes. It can detect fluoride by naked eye color change and copper by fluorescence enhancement. Interestingly, the nature of the substituent in HNHCB has an effect on the selectivity. The detection limit can be as low as 160 nM for Cu2+ and 1.3 μM for F-. DFT calculations have been performed to demonstrate the structure of HNHCB and its copper complex. Biological applications of HNHCB have been evaluated in HEK 293 and it was found to exhibit membrane permeability for the detection of Cu2+. The sensor HNHCB is also sensitive towards fluoride in commercially available toothpaste. © The Royal Society of Chemistry 2016.

Selective chromo-fluorogenic molecular sensor for dual channel recognition of Cu2+ and F-: Effect of functional group on selectivity

Realistically designed bis(indolyl)methanes from β-chloro-α,β-unsaturated aldehydes exhibited remarkable naked eye sensitivity towards Cu2+ ion. A green one pot technique has been developed for their synthesis using PMA-Cellulose as a reusable solid acid support/catalyst under solvent free condition. The procedure offered excellent yields within a short period of time. © 2015 Royal Society of Chemistry.

An efficient solvent-free synthesis of bis(indolyl)methane-based naked eye chemosensor for Cu2+ ion from Î²-chloro-Î±,Î²-unsaturated aldehydes using PMA-Cellulose as a solid phase reusable catalyst

A symmetrical azine derivative, N,N′-Bis(imidazo[1,2-a]pyridine-2- ylmethylene hydrazine (sensor L) has been synthesized and its fluorescence sensing potential towards metal ions has been demonstrated using simple fluorometric technique. The sensor shows high fluorescence selectivity and high sensitivity towards Hg2+ ion in aqueous-methanol media. Only Hg 2+ ion is found to effectively enhance fluorescence quantum yield of the nearly non-fluorescent sensor. The sensor can effectively distinguish Hg2+ from Cd2+ or Zn2+ ion within the same group via different mechanistic pathway i.e. chelation enhanced fluorescence (CHEF) effect for Hg2+ ion and charge transfer (CT) mechanism for Cd2+ or Zn2+ ion. Experimental spectral properties have been correlated with theoretical calculation based on Density Functional Theory method. © 2011 Elsevier B.V.

Highly selective and sensitive fluorescence reporter for toxic Hg(II) ion by a synthetic symmetrical azine derivative

A simple intramolecular charge transfer (ICT) compound, 5-(4-dimethylamino-phenyl)-penta-2,4-dienoic acid methyl ester (DPDAME), has been documented to be a potential molecular reporter for probing microheterogeneous environments of a model transport protein bovine serum albumin (BSA) using spectroscopic techniques. Meteoric modifications to the emission profile of DPDAME upon addition of BSA come out to be a result of its binding to hydrophobic subdomain IIA. The highly polarity-sensitive ICT emission of DPDAME is found to be a proficient extrinsic molecular reporter for efficient mapping of native, intermediate, unfolded, and refolded states of the protein. Experimental data coupled with a reinforcing support from theoretical simulation using CHARMM22 software confirm the binding site of the probe to be the subdomain IIA of BSA, while FRET study reveals a remarkably close approach of our extrinsic molecular reporter to Trp-212 (in domain IIA): the distance between DPDAME and Trp-212 is 1.437 nm. The caliber of DPDAME as an external fluorescence marker also extends to the depiction of protein-surfactant (BSA-SDS) interaction to commendable fruition. Additionally, the protective action of small amounts of SDS on urea-denatured protein is documented by polarity-sensitive ICT emission of the probe. The present study also reflects the enhancement of the stability of BSA with respect to chemically induced denaturation by urea as a result of binding to the probe DPDAME. © 2010 American Chemical Society.

Journal of Physical Chemistry B

Exploring hydrophobic subdomain iia of the protein bovine serum albumin in the native, intermediate, unfolded, and refolded states by a small fluorescence molecular reporter

Journal	Data powered by TypesetSensors and Actuators, B: Chemical
Publisher	Data powered by TypesetELSEVIER SCIENCE SA
ISSN	0925-4005
Open Access	No