title: The binding site of zinc and indium metal to amino acid derivatized squarate complexes - Implications in inhibitor and mediator designs.
abstract: Three novel metal squaric acid-peptide complexes, SQI-SQIII were prepared by addition of indium triflate or zinc chloride to the previously reported compounds [1], 3-(hydroxymethylamino)-4-(l-isoleucine methyl ester)-3-cyclobutene-1,2-dione (squarate 1), and 3-(hydroxymethylamino)-2-(l-isoleucine methyl ester)-4-thioxo-2-cyclobuten-1-one (squarate 2). The structures of SQI-SQIII were elucidated using NMR analysis. The electrochemical applications of two of these metal-squaric acid systems (SQI and SQII) were also investigated. Incorporation of SQII as a mediator, in the previously optimized Pt/p(HEMA)/p(pyrrole)/GOx electrode using the ionic liquid [bmim][BF(4)] as the solvent medium, produced a biosensor with enhanced properties, namely a sensitivity of 175.9mA/M d-glucose, working potential of +200mV, large linear range (0-12mM) and a detection limit of 1x10(-6)M.
authors.affiliation: Department of Chemistry, The University of The West Indies, St. Augustine, Trinidad and Tobago. natasha.ramroopsingh@utt.edu.tt
authors.forename: Natasha
authors.initials: N
authors.lastname: Ramroop-Singh
authors.forename: Dyer
authors.initials: D
authors.lastname: Narinesingh
authors.forename: Gurdial
authors.initials: G
authors.lastname: Singh
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Seto
authors.forename: Anthony B
authors.initials: AB
authors.lastname: Comeau
mesh_terms: D000596:Amino Acids / Q000138:chemical synthesis / Q000737:chemistry*; D001665:Binding Sites; D015374:Biosensing Techniques / Q000379:methods*; D003503:Cyclobutanes / Q000138:chemical synthesis / Q000737:chemistry*; D005947:Glucose / Q000032:analysis*; D007204:Indium / Q000737:chemistry*; D057230:Limit of Detection; D009682:Magnetic Resonance Spectroscopy; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry; D015032:Zinc / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D003503:Cyclobutanes; D010455:Peptides; D007204:Indium; D005947:Glucose; D015032:Zinc; C030042:squaric acid