@article{rhodes_brewer_folmer_franzen_2008, title={Investigation of hexadecanethiol self-assembled monolayers on cadmium tin oxide thin films}, volume={516}, ISSN={["0040-6090"]}, DOI={10.1016/j.tsf.2007.08.098}, abstractNote={This study reports the use of variable angle reflectance Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy to investigate the formation of a 1-hexadecanethiol adlayer on cadmium tin oxide (CTO) thin film surfaces. These adlayers appear to be robust, ordered monolayers. The optical and electronic properties of CTO thin films chemically vapor deposited onto glass substrates were also investigated. The reflectance of the CTO films was dependent upon the incident angle of the impinging radiation and revealed a reflectance decrease indicative of a plasma frequency in the mid-IR using p-polarized radiation.}, number={8}, journal={THIN SOLID FILMS}, author={Rhodes, Cnissy L. and Brewer, Scott H. and Folmer, Jaap and Franzen, Stefan}, year={2008}, month={Feb}, pages={1838–1842} }
 @article{moses_brewer_kraemer_fuierer_lowe_agbasi_sauthier_franzen_2007, title={Detection of DNA hybridization on indium tin oxide surfaces}, volume={125}, ISSN={["0925-4005"]}, DOI={10.1016/j.snb.2007.03.009}, abstractNote={Indium tin oxide (ITO) surfaces were modified with ssDNA by coupling oligonucleotides to a monolayer of 12-phosphonododecanoic acid (12-PDA) on ITO surfaces. This coupling involved the formation of an amide bond between the carboxylic acid moiety of 12-PDA to the amine group of a 5′-aminopropyl-labeled single strand of DNA. The self-assembled monolayer of 12-PDA and surface-attached oligonucleotides were characterized by X-ray photoelectron and reflectance FTIR spectroscopy. Detection of selective surface DNA hybridization was achieved by labeling the target ssDNA with gold nanoparticles. The presence of gold nanoparticles was probed using X-ray photoelectron spectroscopy, stripping voltammetry, atomic force microscopy, thermography, photoelectrochemistry (chronoamperometry) and cyclic voltammetry (CV). CV was used to successfully detect DNA hybridization for nanoparticle concentrations as low as 10 pM when using the gold nanoparticles bound to an ITO electrode as catalysts for the electrochemical oxidation of FeCl2. The studies described here provided the basis for surface attachment methodology for various electrochemical and thermographic sensing methods that use ITO thin films as a substrate.}, number={2}, journal={SENSORS AND ACTUATORS B-CHEMICAL}, author={Moses, Selina and Brewer, Scott H. and Kraemer, Stephan and Fuierer, Ryan R. and Lowe, Lisa B. and Agbasi, Chiamaka and Sauthier, Marc and Franzen, Stefan}, year={2007}, month={Aug}, pages={574–580} }
 @article{franzen_jasaitis_belyea_brewer_casey_macfarlane_stanley_vos_martin_2006, title={Hydrophobic distal pocket affects NO-heme geminate recombination dynamics in dehaloperoxidase and H64V myoglobin}, volume={110}, ISSN={["1520-6106"]}, DOI={10.1021/jp056790m}, abstractNote={The recombination dynamics of NO with dehaloperoxidase (DHP) from Amphitrite ornata following photolysis were measured by femtosecond time-resolved absorption spectroscopy. Singular value decomposition (SVD) analysis reveals two important basis spectra. The first SVD basis spectrum reports on the population of photolyzed NO molecules and has the appearance of the equilibrium difference spectrum between the deoxy and NO forms of DHP. The first basis time course has two kinetic components with time constants of tau(11) approximately 9 ps and tau(12) approximately 50 ps that correspond to geminate recombination. The fast geminate process tau(11) arises from a contact pair with the heme iron in a bound state with S = 3/2 spin. The slow geminate process tau(12) corresponds to the recombination from a more remote docking site >3 A from the heme iron with the greater barrier corresponding to a S = 5/2 spin state. The second SVD basis spectrum represents a time-dependent Soret band shift indicative of heme photophysical processes and protein relaxation with time constants of tau(21) approximately 3 ps and tau(22) approximately 17 ps, respectively. A comparison between the more rapid rate constant of the slow geminate phase in DHP-NO and horse heart myoglobin (HHMbNO) or sperm whale myoglobin (SWMbNO) suggests that protein interactions with photolyzed NO are weaker in DHP than in the wild-type MbNOs, consistent with the hydrophobic distal pocket of DHP. The slower protein relaxation rate tau(22) in DHP-NO relative to HHMbNO implies less effective trapping in the docking site of the distal pocket and is consistent with a greater yield for the fast geminate process. The trends observed for DHP-NO also hold for the H64V mutant of SWMb (H64V MbNO), consistent with a more hydrophobic distal pocket for that protein as well. We examine the influence of solution viscosity on NO recombination by varying the glycerol content in the range from 0% to 90% (v/v). The dominant effect of increasing viscosity is the increase of the rate of the slow geminate process, tau(12), coupled with a population decrease of the slow geminate component. Both phenomena are similar to the effect of viscosity on wild-type Mb due to slowing of protein relaxation resulting from an increased solution viscosity and protein surface dehydration.}, number={29}, journal={JOURNAL OF PHYSICAL CHEMISTRY B}, author={Franzen, Stefan and Jasaitis, Audrius and Belyea, Jennifer and Brewer, Scott H. and Casey, Robin and MacFarlane, Alexander W. and Stanley, Robert J. and Vos, Marten H. and Martin, Jean-Louis}, year={2006}, month={Jul}, pages={14483–14493} }
 @misc{franzen_brewer_2006, title={Surface plasmon resonance systems and methods having a variable charge density layer}, volume={7,015,471}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Franzen, S. and Brewer, S.}, year={2006} }
 @article{bin-salamon_brewer_depperman_franzen_kampf_kirk_kumar_lappi_peariso_preuss_et al._2006, title={Testing Bridge-Mediated Differences in Dinuclear Valence Tautomeric Behavior}, volume={45}, ISSN={0020-1669 1520-510X}, url={http://dx.doi.org/10.1021/ic060170y}, DOI={10.1021/ic060170y}, abstractNote={Two structurally characterized dinuclear valence tautomers are described. Cobalt ions are bridged by p- and m-phenylene units connected to 2,2‘-bipyridines. X-ray crystal structures show that the molecules are in the [(CoIII)(CoIII)] forms at ca. 125 K, while spectroscopic studies show that both molecules can achieve the [(CoII)(CoII)] form above 400 K and confirm the [(CoIII)(CoIII)] form below 10 K. Magnetic susceptibility studies are also included. Our results highlight the necessity of studying both crystalline and amorphous samples to distinguish the effects of intrinsic electronic structure and intermolecular forces on valence tautomeric behavior.}, number={11}, journal={Inorganic Chemistry}, publisher={American Chemical Society (ACS)}, author={Bin-Salamon, Sofi and Brewer, Scott H. and Depperman, Ezra C. and Franzen, Stefan and Kampf, Jeff W. and Kirk, Martin L. and Kumar, R. Krishna and Lappi, Simon and Peariso, Katrina and Preuss, Kathryn E. and et al.}, year={2006}, month={May}, pages={4461–4467} }
 @article{brewer_vu_tang_li_franzen_raleigh_dyer_2005, title={Effect of modulating unfolded state structure on the folding kinetics of the villin headpiece subdomain}, volume={102}, ISSN={["0027-8424"]}, DOI={10.1073/pnas.0505432102}, abstractNote={Equilibrium Fourier transform infrared (FTIR) and temperature-jump (T-jump) IR spectroscopic techniques were used to study the thermodynamics and kinetics of the unfolding and folding of the villin headpiece helical subdomain (HP36), a small three-helix protein. A double phenylalanine mutant (HP36 F47L, F51L) that destabilizes the hydrophobic core of this protein also was studied. The double mutant is less stable than wild type (WT) and has been shown to contain less residual secondary structure and tertiary contacts in its unfolded state. The relaxation kinetics after a T-jump perturbation were studied for both HP36 and HP36 F47L, F51L. Both proteins exhibited biphasic relaxation kinetics in response to a T-jump. The folding times for the WT (3.23 μs at 60.2°C) and double phenylalanine mutant (3.01 μs at 49.9°C) at the approximate midpoints of their thermal unfolding transitions were found to be similar. The folding time for the WT was determined to be 3.34 μs at 49.9°C, similar to the folding time of the double phenylalanine mutant at that temperature. The double phenylalanine mutant, however, unfolds faster with an unfolding time of 3.01 μs compared with 6.97 μs for the WT at 49.9°C.}, number={46}, journal={PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA}, author={Brewer, SH and Vu, DM and Tang, YF and Li, Y and Franzen, S and Raleigh, DP and Dyer, RB}, year={2005}, month={Nov}, pages={16662–16667} }
 @article{brewer_wicaksana_maria_kingon_franzen_2005, title={Investigation of the electrical and optical properties of iridium oxide by reflectance FTIR spectroscopy and density functional theory calculations}, volume={313}, number={38355}, journal={Chemical Physics}, author={Brewer, S. H. and Wicaksana, D. and Maria, J. P. and Kingon, A. I. and Franzen, S.}, year={2005}, pages={25–31} }
 @article{brewer_glomm_johnson_knag_franzen_2005, title={Probing BSA binding to citrate-coated gold nanoparticles and surfaces}, volume={21}, ISSN={["0743-7463"]}, DOI={10.1021/la050588t}, abstractNote={The interaction of bovine serum albumin (BSA) with gold colloids and surfaces was studied using zeta-potential and quartz crystal microbalance (QCM) measurements, respectively, to determine the surface charge and coverage. The combination of these two measurements suggests that BSA binding to gold nanoparticles and gold surfaces occurs by an electrostatic mechanism when citrate is present. The binding of BSA to bare gold is nearly two times greater than the binding of BSA to a citrate-coated gold surface, suggesting that protein spreading (denaturation) on the surface may occur followed by secondary protein binding. On the other hand, binding to citrate-coated gold surfaces can be fit to a Langmuir isotherm model to obtain a maximum surface coverage of (3.7 +/- 0.2) x 10(12) molecules/cm(2) and a binding constant of 1.0 +/- 0.3 microM(-1). The zeta-potential measurements show that the stabilization of colloids by BSA has a significant contribution from a steric mechanism because the colloids are stable, even at their isoelectric point (pI approximately 4.6). To be consistent with the observed phenomena, the electrostatic interactions between BSA and citrate must consist of salt-bridges, for example, of the carboxylate-ammonium type, between the citrate and the lysine on the protein surface. The data support the role of strong electrostatic binding but do not exclude contributions from steric or hydrophobic interactions with the surface adlayer.}, number={20}, journal={LANGMUIR}, author={Brewer, SH and Glomm, WR and Johnson, MC and Knag, MK and Franzen, S}, year={2005}, month={Sep}, pages={9303–9307} }
 @article{bin-salamon_brewer_franzen_feldheim_lappi_shultz_2005, title={Supramolecular control of valence-tautomeric equilibrium on nanometer-scale gold clusters}, volume={127}, ISSN={["0002-7863"]}, DOI={10.1021/ja042520q}, abstractNote={This communication describes the preparation and characterization of a valence tautomer complex covalently attached to gold nanoparticles. Variable-temperature IR spectroscopy is used to determine the equilibrium thermodynamic parameters for the valence tautomerization. These results are compared with a nonsurface combined valence tautomer complex. The results show that surface confinement attenuates both ΔH° and ΔS°. We attribute these changes to a reduced accessible molecular surface area.}, number={15}, journal={JOURNAL OF THE AMERICAN CHEMICAL SOCIETY}, author={Bin-Salamon, S and Brewer, S and Franzen, S and Feldheim, DL and Lappi, S and Shultz, DA}, year={2005}, month={Apr}, pages={5328–5329} }
 @article{brewer_franzen_2004, title={Calculation of the electronic and optical properties of indium tin oxide by density functional theory}, volume={300}, ISSN={["1873-4421"]}, DOI={10.1016/j.chemphys.2003.11.039}, abstractNote={Density functional theory (DFT) was used to calculate the bulk electronic and optical properties of indium tin oxide (ITO). The ITO model was constructed replacing indium atoms with tin atoms in the cubic unit cell of indium oxide. To allow more possibilities for tin atom substitution than afforded by the forty-atom primitive cell of indium oxide all eighty atoms of the unit cell were included in the stoichiometry (In32−xSnxO48) using periodic boundary conditions. A number of properties of ITO were calculated including the optical band gap, charge carrier density and plasma frequency. The dependence of the electronic and optical properties of ITO on a variety of parameters such as the tin content, cubic lattice parameter and the distance between adjacent tin atoms was investigated. The electronic and optical properties agreed well with experimental data and allowed insight into the origin of the electronic and optical properties of ITO.}, number={1-3}, journal={CHEMICAL PHYSICS}, author={Brewer, SH and Franzen, S}, year={2004}, month={May}, pages={285–293} }
 @article{moses_brewer_lowe_lappi_gilvey_sauthier_tenent_feldheim_franzen_2004, title={Characterization of single- and double-stranded DNA on gold surfaces}, volume={20}, ISSN={["0743-7463"]}, DOI={10.1021/la0492815}, abstractNote={Single- and double-stranded deoxy ribonucleic acid (DNA) molecules attached to self-assembled monolayers (SAMs) on gold surfaces were characterized by a number of optical and electronic spectroscopic techniques. The DNA-modified gold surfaces were prepared through the self-assembly of 6-mercapto-1-hexanol and 5‘-C6H12SH -modified single-stranded DNA (ssDNA). Upon hybridization of the surface-bound probe ssDNA with its complimentary target, formation of double-stranded DNA (dsDNA) on the gold surface is observed and in a competing process, probe ssDNA is desorbed from the gold surface. The competition between hybridization of ssDNA with its complimentary target and ssDNA probe desorption from the gold surface has been investigated in this paper using X-ray photoelectron spectroscopy, chronocoulometry, fluorescence, and polarization modulation−infrared reflection absorption spectroscopy (PM−IRRAS). The formation of dsDNA on the surface was identified by PM−IRRAS by a dsDNA IR signature at ∼1678 cm-1 that was confirmed by density functional theory calculations of the nucleotides and the nucleotides' base pairs. The presence of dsDNA through the specific DNA hybridization was additionally confirmed by atomic force microscopy through colloidal gold nanoparticle labeling of the target ssDNA. Using these methods, strand loss was observed even for DNA hybridization performed at 25 °C for the DNA monolayers studied here consisting of attachment to the gold surfaces by single Au−S bonds. This finding has significant consequence for the application of SAM technology in the detection of oligonucleotide hybridization on gold surfaces.}, number={25}, journal={LANGMUIR}, author={Moses, S and Brewer, SH and Lowe, LB and Lappi, SE and Gilvey, LBG and Sauthier, M and Tenent, RC and Feldheim, DL and Franzen, S}, year={2004}, month={Dec}, pages={11134–11140} }
 @article{smith_lappi_brewer_dembowy_belyea_franzen_2004, title={Covalent attachment of a nickel nitrilotriacetic acid group to a germanium attenuated total reflectance element}, volume={20}, ISSN={["0743-7463"]}, DOI={10.1021/la034194i}, abstractNote={The surface of a germanium internal reflectance element (IRE) was modified to bind 6X-histidine (his)-tagged biomolecules. The step-by-step surface modification was monitored via single-pass attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FT-IR). Initially an adlayer of 7-octenyltrimethoxysilane (7-OTMS) was formed on the Ge crystal through the surface hydroxyl groups, which were produced via ozonolysis of the Ge surface. The vinyl moiety of 7-OTMS was oxidized to a carboxylic acid, which was activated by 1,1‘-carbonydiimidazole (CDI) to produce a labile imidazole. The labile imidazole that resulted from the CDI coupling was then displaced by the primary amine of nitrilotriacetic acid (NTA). Nickel sulfate was added to the system, and it coordinated with the three carbonyl groups and the nitrogen on NTA, thus leaving the ability of Ni to coordinate with two adjacent histidine residues. Binding of his-tagged biotin to nickel nitrilotriacetic acid (Ni-NTA) was observed by ATR-FT-IR spectroscopy. The surface modification method presented in this paper had minimal nonspecific binding, the Ni-NTA surface was reusable if stored properly, and complete removal of the organic surface was achievable.}, number={4}, journal={LANGMUIR}, author={Smith, BM and Lappi, SE and Brewer, SH and Dembowy, S and Belyea, J and Franzen, S}, year={2004}, month={Feb}, pages={1184–1188} }
 @article{brewer_allen_lappi_chasse_briggman_gorman_franzen_2004, title={Infrared detection of a phenylboronic acid terminated alkane thiol monolayer on gold surfaces}, volume={20}, ISSN={["0743-7463"]}, DOI={10.1021/la035037m}, abstractNote={Polarization modulation infrared reflectance absorption spectroscopy (PM-IRRAS) and infrared reflectance absorption spectroscopy (IRRAS) have been used to characterize the formation of a self-assembled monolayer of N-(3-dihydroxyborylphenyl)-11-mercaptoundecanamide) (abbreviated PBA) on a gold surface and the subsequent binding of various sugars to the PBA adlayer through the phenylboronic acid moiety to form a phenylboronate ester. Vibrationally resonant sum frequency generation (VR-SFG) spectroscopy confirmed the ordering of the substituted phenyl groups of the PBA adlayer on the gold surface. Solution FTIR spectra and density functional theory were used to confirm the identity of the observed vibrational modes on the gold surface of PBA with and without bound sugar. The detection of the binding of glucose on the gold surface was confirmed in part by the presence of a C-O stretching mode of glucose and the observed O-H stretching mode of glucose that is shifted in position relative to the O-H stretching mode of boronic acid. An IR marker mode was also observed at 1734 cm(-1) upon the binding of glucose. Additionally, changes in the peak profile of the B-O stretching band were observed upon binding, confirming formation of a phenylboronate ester on the gold surface. The binding of mannose and lactose were also detected primarily through the IR marker mode at approximately 1736 to 1742 cm(-1) depending on the identity of the bound sugar.}, number={13}, journal={LANGMUIR}, author={Brewer, SH and Allen, AM and Lappi, SE and Chasse, TL and Briggman, KA and Gorman, CB and Franzen, S}, year={2004}, month={Jun}, pages={5512–5520} }
 @article{brewer_franzen_2003, title={A quantitative theory and computational approach for the vibrational Stark effect}, volume={119}, ISSN={["0021-9606"]}, DOI={10.1063/1.1578471}, abstractNote={Density functional theory (DFT) has been used to calculate the vibrational Stark tuning rates of a variety of nitriles and carbonyls in quantitative agreement with experimental values with a correction factor of f=1.1 for the local electric field. These calculations show that the vibrational Stark tuning rate has an anharmonic contribution and a contribution due to geometric distortions caused in the molecules due to the applied electric field. The anharmonic and geometric distortion components of the vibrational Stark tuning rate were calculated by the frequency dependence of the CN or CO stretching mode with varying applied electric fields by using the optimized structure in zero applied field or allowing the structure to optimize in the applied electric field, respectively. The changes in the calculated frequency of the CN or CO stretching mode, bond length, and dipole moment of this bond with varying applied electric fields are shown. The transition polarizability and the difference polarizability were also calculated by DFT for comparison to the experimental data on nitriles and carbonyls. The DFT calculations suggest that the sign of the transition polarizability is negative and this result in turn has an effect on the experimental data analysis since the sign of the transition polarizability is not determined by experiment.}, number={2}, journal={JOURNAL OF CHEMICAL PHYSICS}, author={Brewer, SH and Franzen, S}, year={2003}, month={Jul}, pages={851–858} }
 @article{lowe_brewer_kramer_fuierer_qian_agbasi-porter_moses_franzen_feldheim_2003, title={Laser-induced temperature jump electrochemistry on gold nanoparticle-coated electrodes}, volume={125}, ISSN={["0002-7863"]}, DOI={10.1021/ja036672h}, abstractNote={Laser-induced temperature jumps (LITJs) at gold nanoparticle-coated indium tin oxide (ITO) electrodes in contact with electrolyte solutions have been measured using temperature-sensitive redox probes and an infrared charge-coupled device. Upon irradiation with 532 nm light, interfacial temperature changes of ca. 20 degrees C were recorded for particle coverages of ca. 1 x 1010 cm-2. In the presence of a redox molecule, LITJ yields open-circuit photovoltages and photocurrents that are proportional to the number of particles on the surface. When ssDNA was used to chemisorb nanoparticles to the ITO surface, solution concentrations as low as 100 fM of target ssDNA-modified nanoparticles could be detected at the electrode surface.}, number={47}, journal={JOURNAL OF THE AMERICAN CHEMICAL SOCIETY}, author={Lowe, LB and Brewer, SH and Kramer, S and Fuierer, RR and Qian, GG and Agbasi-Porter, CO and Moses, S and Franzen, S and Feldheim, DL}, year={2003}, month={Nov}, pages={14258–14259} }
 @article{franzen_fritsch_brewer_2002, title={Experimental observation of anharmonic coupling of the heme-doming and iron-ligand out-of-plane vibrational modes confirmed by density functional theory}, volume={106}, ISSN={["1520-6106"]}, DOI={10.1021/jp0261197}, abstractNote={In the deoxy ferrous state of histidine-ligated heme proteins, the iron−histidine band (νFe-His) has been assigned as a stretching mode that involves a two-body motion involving the iron and histidine combined with a minor amount of heme doming. An analogous Raman band, νFe-L has been observed in the proximal cavity mutant of H93G myoglobin where the Raman band of a series of nonnative axial ligands, L, can be compared. The H93G mutant of myoglobin consists of substitution of the proximal histidine, H93, by glycine. This replacement abolishes the sole covalent connection between the globin and the heme iron and creates a cavity that can be occupied by exogenous ligands, L, by dialysis. In the present study, the iron−axial-ligand out-of-plane vibration, νFe-L, for a series deoxy ferrous heme-iron adducts H93G(L) has been measured as a function of temperature, where L = imidazole (Im), 4-methyl imidazole (4-Me Im), 2-methyl imidazole (2-Me Im), 1-methyl imidazole (1-Me Im), 4-bromo imidazole (4-Br Im), and 2,4-dimethyl imidazaole (2,4-diMe Im). Density functional theory calculations show that anharmonic coupling between low wavenumber heme-doming and iron−ligand out-of-plane modes can account for the calculated νFe-L frequency shifts. These calculations parallel the experimental observed trends for temperature-dependent Raman spectra for all of the adducts except H93G(1-Me Im).}, number={44}, journal={JOURNAL OF PHYSICAL CHEMISTRY B}, author={Franzen, S and Fritsch, K and Brewer, SH}, year={2002}, month={Nov}, pages={11641–11646} }
 @article{brewer_brown_franzen_2002, title={Formation of thiolate and phosphonate adlayers on indium-tin oxide: Optical and electronic characterization}, volume={18}, DOI={10.1021/la01572d}, number={18}, journal={Langmuir}, author={Brewer, S. H. and Brown, D. A. and Franzen, Stefan}, year={2002}, pages={6857–6865} }
 @article{brewer_franzen_2002, title={Indium tin oxide plasma frequency dependence on sheet resistance and surface adlayers determined by reflectance FTIR spectroscopy}, volume={106}, ISSN={["1520-6106"]}, DOI={10.1021/jp026600x}, abstractNote={Variable angle reflectance FTIR spectroscopy was used to investigate the optical properties of indium tin oxide (ITO) and fluorine-doped tin oxide (SFO) thin films in the near-IR spectral region. The reflectance data were used to determine the plasma frequency and the electronic scattering time using the Drude free-electron model, the dielectric function of ITO, and the two- and three-phase Fresnel equations for reflection. The reflectance, plasma frequency, and electronic scattering time of ITO thin films were found to be dependent on the sheet resistance. Surface adlayers were also found to affect the reflectance and the position of the plasma frequency of the ITO thin films. The reflectance and observed plasma frequency for the SFO thin films were lower than those for any of the ITO films studied.}, number={50}, journal={JOURNAL OF PHYSICAL CHEMISTRY B}, author={Brewer, SH and Franzen, S}, year={2002}, month={Dec}, pages={12986–12992} }
 @article{brewer_franzen_2002, title={Optical properties of indium tin oxide and fluorine-doped tin oxide surfaces: correlation of reflectivity, skin depth, and plasmon frequency with conductivity}, volume={338}, ISSN={["0925-8388"]}, DOI={10.1016/S0925-8388(02)00217-7}, abstractNote={Variable angle reflectance FTIR was used to investigate the reflectance of thin films of either indium tin oxide (ITO) or fluorine-doped tin oxide (SFO) on glass substrates in the mid-IR. The reflectance was observed to depend on the incident angle, wavenumber, and the polarization used. The Drude model and the Fresnel equations for reflection at a single dielectric boundary were used to interpret these results in terms of the conductivity, reflectivity, skin depth, and plasmon frequency of the metal oxides. The skin depth of thin film ITO electrodes was found to depend on the sheet resistance linearly, while the reflectance varied according to the square root of the sheet resistance. The method shows that an optical probe can be used to determine the electrical properties of metal oxide films in a noninvasive approach.}, number={1-2}, journal={JOURNAL OF ALLOYS AND COMPOUNDS}, author={Brewer, SH and Franzen, S}, year={2002}, month={May}, pages={73–79} }