The binding site of zinc and indium metal to amino acid derivatized squarate complexes - Implications in inhibitor and mediator designs.
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.
Ramroop-Singh
Natasha
N
Department of Chemistry, The University of The West Indies, St. Augustine, Trinidad and Tobago. natasha.ramroopsingh@utt.edu.tt
Narinesingh
Dyer
D
Singh
Gurdial
G
Seto
Christopher T
CT
Comeau
Anthony B
AB
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*
D000596:Amino Acids; D003503:Cyclobutanes; D010455:Peptides; D007204:Indium; D005947:Glucose; D015032:Zinc; C030042:squaric acid