TY - JOUR
T1 - Characterization of oxidoreductase-redox polymer electrostatic film assembly on gold by surface plasmon resonance spectroscopy and Fourier transform infrared-external reflection spectroscopy
AU - Simonian, Aleksandr L.
AU - Revzin, Alexander
AU - Wild, James R.
AU - Elkind, Jerry
AU - Pishko, Michael V.
N1 - Funding Information:
The authors would like to thank Texas Instruments Incorporated for providing the TISPR-1 sensor and Experimenter’s Kit. Help and comments provided by Dr. Clem Furlong, Dr. Dwight Bartholomew, Dr. Anita Strong, Dr. John Quinn and Dr. Li Sun are greatly appreciated. We would also like to thank Dr. Richard Crooks from the Department of Chemistry at Texas A&M University and his group members for the use of FT-IR–ERS instrument. Financial support for JWR was provided in part by the Department of Energy Office of National Security and Nonproliferation, and by US Army Medical Research and Materiel Command. MVP, AS, and AR thank the National Science Foundation (CTS-9875372) and the US Department of the Army and the National Medical Technology Testbed Inc. (DAMD17-97-2-7016) for funding. MVP acknowledges the support of the Alfred P. Sloan Foundation through a research fellowship. “This work does not necessarily reflect the position or the policy of the government or NMTB, and that no official endorsement should be inferred.” This work was partially funded by the US Department of the Army and the National Medical Technology Testbed Inc. (DAMD17-97-2-7016). “This work does not necessarily reflect the position or the policy of the government or NMTB, and that no official endorsement should be inferred.”
PY - 2002/8/27
Y1 - 2002/8/27
N2 - The electrostatic assembly of nanocomposite thin films consisting of alternating layers of an organometallic redox polymer (RP) and oxidoreductase enzymes, glucose oxidase (GOX), lactate oxidase (LOX) and pyruvate oxidase (PYX), was investigated. Multilayer nanostructures were fabricated on gold surfaces by the deposition of an anionic self-assembled monolayer of 11-mercaptoundecanoic acid, followed by the electrostatic attachment of a cationic RP, poly(vinylpyridine Os(bis-bipyridine)2Cl-co-allylamine) (PVP-Os-AA), and anionic oxidoreductase enzymes. Surface plasmon resonance (SPR) spectroscopy, Fourier transform infrared external reflection spectroscopy (FT-IR-ERS) and electrochemistry were employed to characterize the assembly of these nanocomposite films. The surface concentration of GOX was found to be 2.4ng/mm2 for the first enzyme layer and 1.96ng/mm2 for the second enzyme layer, while values of 10.7 and 1.3ng/mm2 were obtained for PYX and LOX, respectively. The apparent affinity constant for GOX adsorption was found to be 8×107M-1. FT-IR-ERS was used to verify the incorporation of GOX and its conformational stability inside of these nanocomposite thin films. An SPR instrument with a flow-through cell was modified by additions of Ag/AgCl reference and Pt counter electrodes, with the gold-coated SPR surface film serving as the working electrode. This enabled real-time observation of the assembly of sensing components and immediate, in situ electrochemical verification of substrate-dependent current upon the addition of enzyme to the multilayer structure. A glucose-dependant amperometric response with sensitivity of 0.197μA/cm2/mM for a linear range of 1-10mM of glucose was obtained. The SPR and FT-IR-ERS studies also showed no desorption of polymer or enzyme from the nanocomposite RP-GOX structure when stored in aqueous environment occurred over the period of 3 weeks, suggesting that decreasing substrate sensitivity with time was due to loss of enzymatic activity rather than loss of film compounds from the nanostructure.
AB - The electrostatic assembly of nanocomposite thin films consisting of alternating layers of an organometallic redox polymer (RP) and oxidoreductase enzymes, glucose oxidase (GOX), lactate oxidase (LOX) and pyruvate oxidase (PYX), was investigated. Multilayer nanostructures were fabricated on gold surfaces by the deposition of an anionic self-assembled monolayer of 11-mercaptoundecanoic acid, followed by the electrostatic attachment of a cationic RP, poly(vinylpyridine Os(bis-bipyridine)2Cl-co-allylamine) (PVP-Os-AA), and anionic oxidoreductase enzymes. Surface plasmon resonance (SPR) spectroscopy, Fourier transform infrared external reflection spectroscopy (FT-IR-ERS) and electrochemistry were employed to characterize the assembly of these nanocomposite films. The surface concentration of GOX was found to be 2.4ng/mm2 for the first enzyme layer and 1.96ng/mm2 for the second enzyme layer, while values of 10.7 and 1.3ng/mm2 were obtained for PYX and LOX, respectively. The apparent affinity constant for GOX adsorption was found to be 8×107M-1. FT-IR-ERS was used to verify the incorporation of GOX and its conformational stability inside of these nanocomposite thin films. An SPR instrument with a flow-through cell was modified by additions of Ag/AgCl reference and Pt counter electrodes, with the gold-coated SPR surface film serving as the working electrode. This enabled real-time observation of the assembly of sensing components and immediate, in situ electrochemical verification of substrate-dependent current upon the addition of enzyme to the multilayer structure. A glucose-dependant amperometric response with sensitivity of 0.197μA/cm2/mM for a linear range of 1-10mM of glucose was obtained. The SPR and FT-IR-ERS studies also showed no desorption of polymer or enzyme from the nanocomposite RP-GOX structure when stored in aqueous environment occurred over the period of 3 weeks, suggesting that decreasing substrate sensitivity with time was due to loss of enzymatic activity rather than loss of film compounds from the nanostructure.
KW - Biosensor
KW - Electrostatic film assembly
KW - Enzyme electrode
KW - Oxidoreductase
KW - Redox polymer
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U2 - 10.1016/S0003-2670(02)00603-7
DO - 10.1016/S0003-2670(02)00603-7
M3 - Article
AN - SCOPUS:0037183452
SN - 0003-2670
VL - 466
SP - 201
EP - 212
JO - Analytica Chimica Acta
JF - Analytica Chimica Acta
IS - 2
ER -