Effect of metal oxidation state on FRET: a Cu(i) silent but selectively Cu(ii) responsive fluorescent reporter and its bioimaging applications. Issue 4 (3rd December 2014)

• Record Type: Journal Article
• Authors: Pal, Siddhartha; Sen, Buddhadeb; Lohar, Somenath; Mukherjee, Manjira; Banerjee, Samya; Chattopadhyay, Pabitra
• Is Part Of: Dalton transactions. Volume 44:Issue 4(2015)
• Page Start: 1761
• Page End: 1768
• Publication Date: 2014-12-03
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/c4dt03381g
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : A new structurally characterized cell permeable rhodamine-cinnamaldehyde hybrid (HL ) behaves as a Cu(ii ) ions selective chemosensor through FRET process which depends on +2 state of copper ion exclusively. Abstract : Copper(ii ) and copper(i ) complexes of a newly designed and crystallographically characterized Schiff base (HL ) derived from rhodamine hydrazide and cinnamaldehyde were isolated in pure form formulated as [Cu(L)(NO3 )] (L-Cu) (1 ) and [Cu(HL)(CH3 CN)(H2 O)]ClO4 (HL-Cu) (2 ), and characterized by physicochemical and spectroscopic tools. Interestingly, complex1 but not2 offers red fluorescence in solution state, and eventuallyHL behaves as a Cu(ii ) ions selective FRET based fluorosensor in HEPES buffer (1 mM, acetonitrile–water: 1/5, v/v) at 25 °C at biological pH with almost no interference of other competitive ions. The dependency of the FRET process on the +2 oxidation state of copper has been nicely supported by exhaustive experimental studies comprising electronic, fluorimetric, NMR titration, and theoretical calculations. The sensing ability ofHL has been evaluated by the LOD value towards Cu(ii ) ions (83.7 nM) and short responsive time (5–10 s). Even the discrimination of copper(i ) and copper(ii ) has also been done using only UV-Vis spectroscopic study. The efficacy of this bio-friendly probe has been determined by employingHL to detect the intercellular distribution of Cu(ii ) ions in HeLa cells by developing image under fluorescence microscope.