title: Octaoctyl-substituted lutetium bisphthalocyanine for NADH biosensing.
abstract: Cyclic voltammetric and Raman and UV-vis spectroscopic measurements were performed on thin films of nonperipherally substituted bis[1,4,8,11,15,18,22,25-octakis(octyl)phthalocyaninato] lutetium(III) (R16LuPc2). Voltammograms exhibit one-electron quasi-reversible redox processes in 1.5 M LiClO4 aqueous solutions. The red-shift of the Q-band of R16LuPc2 in the UV-visible absorption spectra upon oxidation is attributed to the shortening of the inter-ring distance between the two phthalocyanine moieties. This observation is also consistent with the shift in the redox-sensitive vibrational modes in the Raman spectra due to the localization of the positive charge on phthalocyanine moieties. Neutralization of the oxidized R16LuPc2(+) film by dihydronicotinamide adenine dinucleotide (NADH) using different concentrations varying from 0.05 to 1 mM has been studied by UV-vis absorption and Raman spectroscopies. The reduction processes for a three month old film were found to be slower than those for freshly prepared films and showed a dependence upon NADH concentration. The data provide a basis for application of R16LuPc2 as a sensor for NADH.
authors.affiliation: The Wolfson Centre for Materials Processing, Brunel University , Uxbridge, Middlesex UB8 3PH, U.K.
authors.forename: C
authors.initials: C
authors.lastname: Pal
authors.forename: A K
authors.initials: AK
authors.lastname: Sharma
authors.forename: A N
authors.initials: AN
authors.lastname: Cammidge
authors.forename: M J
authors.initials: MJ
authors.lastname: Cook
authors.forename: A K
authors.initials: AK
authors.lastname: Ray
mesh_terms: D040761:Biomimetic Materials / Q000737:chemistry*; D015374:Biosensing Techniques; D056831:Coordination Complexes / Q000737:chemistry*; D055664:Electrochemical Techniques; D007211:Indoles / Q000737:chemistry*; D015394:Molecular Structure; D009243:NAD / Q000032:analysis*; D010084:Oxidation-Reduction; D013059:Spectrum Analysis, Raman
chemical_list: D056831:Coordination Complexes; D007211:Indoles; D009243:NAD