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Lohar S.,University of Burdwan | Sengupta A.,Visva Bharati University | Chattopadhyay A.,Visva Bharati University | Matalobos J.S.,Facultade de Quimica | Das D.,University of Burdwan
European Journal of Inorganic Chemistry | Year: 2014

The antipyrine-based fluorescence probe daph, structurally characterized by single-crystal X-ray diffraction, can recognize both Zn2+ (at 520 nm, yellow) and Al3+ (at 490 nm, green). However, Al3+ selectivity is enhanced significantly when the dinuclear ZnII-daph complex is used as a sensor, which senses Al3+ by a displacement approach. The binding constants of daph for Zn2+ and Al3+ are (4.9±0.2)×104 and (3±0.1)×105 M-1, respectively. The higher water solubility of 2014 Wiley-VCH Verlag GmbH & Co. the ZnII-daph complex allows the detection of Al3+ in a greener way (0.1 M HEPES buffer, ethanol/water = 1:9, v/v, pH 7.4). Moreover, the detection limit of the ZnII-daph complex for Al3+ is higher (2.5×10-9 M) than that of free daph (4.6×10-8 M). Alkali and alkaline-earth metal ions, Cd2+, Hg2+, and Pb2+, and 3d metal ions do not interfere. Both daph and the ZnII-daph complex are capable of intracellular Al3+ detection. © 2014 Wiley-VCH Verlag GmbH & Co.

Sahana A.,University of Burdwan | Banerjee A.,University of Burdwan | Lohar S.,University of Burdwan | Das S.,University of Burdwan | And 4 more authors.
Inorganica Chimica Acta | Year: 2013

A naphthalene based fluorescent probe, 1-((Z)-(naphthalene-4-ylimino) methyl)naphthalene-2-ol (L) has been synthesized by condensing 1-naphthyl amine with 2-hydroxy naphthaldehyde. The structure of L has been established by single crystal X-ray structure. It selectively binds Al3+ with a binding constant (Ka) of 1.83 × 105 M-1/2 and detection limit of 1.0 × 10-7 M. Moreover, [L-Al3+] complex can detect NO2 - ion as low as 5.7 × 10 -8 M. Binding of L to Al3+ and [L-Al3+] complex to NO2 - ion has been established by different spectroscopic studies. The probe is very effective for detection of intracellular Al3+ through fluorescence microscopic imaging.© 2012 Elsevier B.V. All rights reserved.

Banerjee A.,University of Burdwan | Sahana A.,University of Burdwan | Das S.,University of Burdwan | Lohar S.,University of Burdwan | And 4 more authors.
Dalton Transactions | Year: 2013

A pyrene-thiophene conjugate has been used for the efficient detection of intracellular irons through the generation of bright green luminescence. Amongst three different probes being reported, it is observed that the efficiency for the naked eye green luminescent detection of iron increases on moving from naphthalene to anthracene to pyrene. The developed technique may be very useful to monitor iron and zinc supplementation as single micronutrients in living systems through the construction of an INHIBIT logic gate. © 2013 The Royal Society of Chemistry.

Guha S.,University of Burdwan | Lohar S.,University of Burdwan | Banerjee A.,University of Burdwan | Sahana A.,University of Burdwan | And 4 more authors.
Talanta | Year: 2012

A thiophene-coumarin hybrid molecule, (6E)-6-((thiophen-2-yl) methyleneamino)-2H-chromen-2-one (TMC) has been prepared and its single crystal X-ray structure is reported. TMC can selectively detect Cr 3+ in presence of other common cations. Both TMC and its Cr 3+ complex are well characterized by different spectroscopic techniques like 1H NMR, QTOF-MS ES +, FTIR and elemental analysis as well. TMC exhibits fluorescence enhancement upon binding Cr 3+ in CH 3CN-HEPES buffer (0.02 M, pH 7.4) (4:6, v/v) medium. Detection limit of the method is 1 × 10 -6 M. Binding constant is estimated with the Benesi-Hildebrand method and the value 8 × 10 4 indicates a fairly strong interaction between TMC and Cr 3+. Speciation studies have been performed in a fast and environment friendly way using least sample volume, less hazardous chemicals and solvents. Cr 3+ assisted restricted rotation around the imine bond and inhibited photo-induced electron transfer from the N,S-donor sites to the coumarin unit are responsible for fluorescence enhancement. TMC is capable to detect intracellular Cr 3+ in living cells. © 2011 Elsevier B.V. All rights reserved.

Karak D.,University of Burdwan | Lohar S.,University of Burdwan | Banerjee A.,University of Burdwan | Sahana A.,University of Burdwan | And 4 more authors.
RSC Advances | Year: 2012

A naphthalene based compound, 1-((E)-(2-(2-(phenylthio)ethylthio) phenylimino)methyl)naphthalen-2-ol (L2) has been synthesized and characterized by FTIR, 1H NMR, mass spectra and single crystal X-ray structure analysis. L2 shows a blue shift with a large fluorescence enhancement in the presence of Al3+ which is attributed to a chelation-enhanced fluorescence (CHEF) effect with inhibition of an intramolecular charge transfer (ICT) process and cis/trans isomerization. L 2 binds to Al3+ with 2:1 stoichiometry (mole ratio) with an association constant (Ka) of 0.15 × 104 M -1/2. The detection limit for Al3+ is 5 × 10 -8 M in DMSO/H2O (1:2, v/v). L2 can efficiently detect intracellular Al3+ under fluorescence microscope © 2012 The Royal Society of Chemistry.

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