title: In situ chemichromic studies of interactions between a lutetium bis-octaalkyl-substituted phthalocyanine and selected biological cofactors.
abstract: Spin-coated films, approximately 100 nm thick, of a newly synthesized bis[octakis(octyl)phthalocyaninato] lutetium(III) complex on ultrasonically cleaned glass substrates exhibit pronounced chemichromic behaviour with potential application in healthcare. In situ kinetic optical absorption spectroscopic measurements show that the phthalocyanine Q-band is red shifted by 60 nm upon oxidation arising from exposure to bromine vapour. Recovery to the original state is achieved by the treatment of the oxidized films with nicotinamide adenine dinucleotide and l-ascorbic acid (vitamin C) in an aqueous solution containing 1.5 M lithium perchlorate. The neutralization process is found to be governed by first-order kinetics. The linear increase of the reduction rate with increasing concentration of cofactors provides a basis for calibration of analyte concentrations ranging from 3.5 mM down to 0.03 mM.
authors.affiliation: The Wolfson Centre for Materials Processing, Brunel University, Uxbridge, Middlesex UB8 3PH, UK.
authors.forename: C
authors.initials: C
authors.lastname: Pal
authors.forename: A N
authors.initials: AN
authors.lastname: Cammidge
authors.forename: M J
authors.initials: MJ
authors.lastname: Cook
authors.forename: J L
authors.initials: JL
authors.lastname: Sosa-Sanchez
authors.forename: A K
authors.initials: AK
authors.lastname: Sharma
authors.forename: A K
authors.initials: AK
authors.lastname: Ray
mesh_terms: D001205:Ascorbic Acid / Q000737:chemistry; D056831:Coordination Complexes / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry*; D054833:Isoindoles; D007700:Kinetics; D008024:Ligands; D008187:Lutetium / Q000737:chemistry*; D009243:NAD / Q000737:chemistry; D010084:Oxidation-Reduction
chemical_list: D056831:Coordination Complexes; D007211:Indoles; D054833:Isoindoles; D008024:Ligands; D009243:NAD; D008187:Lutetium; D001205:Ascorbic Acid; C013647:phthalocyanine