Scientific Publications 2009
2009. "(SO2)-S-34-O-16: High-resolution analysis of the (030),(101), (111), (002) and (201) vibrational states; determination of equilibrium rotational constants for sulfur dioxide and anharmonic vibrational constants." Journal of Molecular Spectroscopy 253(1):51-54. Abstract High resolution Fourier transform spectra of a sample of sulfur dioxide, enriched in 34S (95.3%). were completely analyzed leading to a large set of assigned lines. The experimental levels derived from this set of transitions were fit to within their experimental uncertainties using Watson-type Hamiltonians. Precise band centers, rotational and centrifugal distortion constants were determined. The following band centers in cm-1 were obtained: ν0(3ν2)=1538.720198(11), ν0(ν1+ν3)=2475.828004(29), ν0(ν1+ν2+ν3)=2982.118600(20), ν0(2ν3)=2679.800919(35), and ν0(2ν1+ν3)=3598.773915(38). The rotational constants obtained in this work have been fit together with the rotational constants of lower lying vibrational states [ W.J. Lafferty, J.-M. Flaud, R.L. Sams and EL Hadjiabib, in press] to obtain equilibrium constants as well as vibration-rotation constants. These equilibrium constants have been fit together with those of 32S16O2 [J.-M. Flaud and W.J. Lafferty, J. Mol. Spectrosc. 16 (1993) 396-402] leading to an improved equilibrium structure. Finally the observed band centers have been fit to obtain anharmonic rotational constants.
2009. "Review of the pyrolysis platform for coproducing bio-oil and biochar." Biofuels, Bioproducts & Biorefining 3(5):547-562. Abstract Pyrolysis is a relatively simple, inexpensive, and robust thermochemical technology for transforming biomass into bio-oil, biochar, and syngas. The robust nature of the pyrolysis technology, which allows considerable flexibility in both the type and quality of the biomass feedstock, combined with a distributed network of small pyrolysis plants, would be compatible with existing agriculture and forestry infrastructure. Bio-oil can be used as a fuel in existing industrial boilers. Biochar can be used with existing infrastructure as a replacement for pulverized coal; however, use of biochar as a soil amendment results in significant environmental and agronomic benefits. Soil application of biochar is a means of sequestering large amounts of C and may have other greenhouse gas benefits. Preliminary reports of the impact of soil biochar applications on crop yields indicate that biochar quality is very important. Biochar is an effective adsorbent for both nutrients and organic contaminants, hence the presence of biochar in soils has been shown to improve water quality in column leaching and field lysimeter studies and it is anticipated to do the same for agricultural watersheds. The pyrolysis platform for producing bio-oil and biochar from biomass appears to be a practical, effective, and environmentally sustainable means of producing large quantities of renewable bioenergy while simultaneously reducing emissions of greenhouse gases. At the present time, the pyrolysis platform is economically marginal because markets for bio-oil and biochar are highly competitive. However, if the USA adopts a program for controlling greenhouse gases, the pyrolysis platform would be highly competitive.
2009. "Molecular Characterization of Nitrogen Containing Organic Compounds in Biomass Burning Aerosols Using High Resolution Mass Spectrometry." Environmental Science & Technology 43(10):3764-3771. doi:10.1021/es803456n Abstract Although nitrogen-containing organic compounds (NOC) are important components of atmospheric aerosols, little is known about their chemical compositions. Here we present detailed characterization of the NOC constituents of biomass burning aerosol (BBA) samples using high resolution electrospray ionization mass spectrometry (ESI/MS). Accurate mass measurements combined with MS/MS fragmentation experiments of selected ions were used to assign molecular structures to individual NOC species. Our results indicate that N-heterocyclic alkaloid compounds - species naturally produced by plants and living organisms - comprise a substantial fraction of NOC in BBA samples collected from test burns of five biomass fuels. High abundance of alkaloids in test burns of ponderosa pine - a widespread tree in the western U.S. areas frequently affected by large scale fires - suggests that N-heterocyclic alkaloids in BBA can play a significant role in dry and wet deposition of fixed nitrogen in this region.
2009. "Involvement of Shewanella oneidensis MR-1 LuxS in Biofilm Development and Sulfur Metabolism." Applied and Environmental Microbiology 75(5):1301-1307. doi:10.1128/AEM.01393-08 Abstract The role of LuxS in Shewanella oneidensis MR-1 has been examined by transcriptomic profiling, biochemical, and physiological experiments. The results indicate that a mutation in luxS alters biofilm development, not by altering quorum-sensing abilities but by disrupting the activated methyl cycle (AMC). The S. oneidensis wild type can produce a luminescence response in the AI-2 reporter strain Vibrio harveyi MM32. This luminescence response is abolished upon the deletion of luxS. The deletion of luxS also alters biofilm formations in static and flowthrough conditions. Genetic complementation restores the mutant biofilm defect, but the addition of synthetic AI-2 has no effect. These results suggest that AI-2 is not used as a quorum-sensing signal to regulate biofilm development in S. oneidensis. Growth on various sulfur sources was examined because of the involvement of LuxS in the AMC. A mutation in luxS produced a reduced ability to grow with methionine as the sole sulfur source. Methionine is a key metabolite used in the AMC to produce a methyl source in the cell and to recycle homocysteine. These data suggest that LuxS is important to metabolizing methionine and the AMC in S. oneidensis.
2009. "Addition of H2O and O-2 to Acetone and Dimethylsulfoxide Ligated Uranyl(V) Dioxocations." Journal of Physical Chemistry A 113(11):2350-2358. doi:10.1021/jp807651c Abstract Gas-phase complexes of the formula [UO2(lig)]+ (lig=acetone (aco) or dimethylsulfoxide (dmso)) were generated by electrospray ionization (ESI) and studied by tandem ion-trap mass spectrometry to determine the general effect of ligand charge donation on the reactivity of UO2+ with respect to water and dioxygen. The original hypothesis that addition of O2 is enhanced by strong σ-donor ligands bound to UO2+ is supported by results from competitive collision-induced dissociation (CID) experiments, which show near exclusive loss of H2O from [UO2(dmso)(H2O)(O2)]+, while both H2O and O2 are eliminated from the corresponding [UO2(aco)(H2O)(O2)]+ species. Ligand-addition reaction rates were investigated by monitoring precursor and product ion intensities as a function of ion storage time in the ion-trap mass spectrometer: these experiments suggest that the association of dioxygen to the UO2+ complex is enhanced when the more basic dmso ligand was coordinated to the metal complex. Conversely, addition of H2O is favored for the analogous complex ion that contains an aco ligand. Experimental rate measurements are supported by density function theory calculations of relative energies, which show stronger bonds between UO2+ and O2 when dmso is the coordinating ligand, while bonds to H2O are stronger for the aco complex.
2009. "Magnetically-Separable and Highly-Stable Enzyme System Based on Crosslinked Enzyme Aggregates Shipped in Magnetite-Coated Mesoporous Silica ." Journal of Materials Chemistry 19(42):7864-7870 . Abstract Magnetically-separable and highly-stable enzyme system was developed by adsorption of enzymes in superparamagnetic hierarchically ordered mesocellular mesoporous silica (M-HMMS) and subsequent enzyme crosslinking. Superparamagnetic nanoparticles were homogeneously incorporated into hierarchically-ordered mesocellular mesoporous silica (HMMS) by the decomposition of preformed iron propionate complex. The size of incorporated superparamagnetic 15 nanoparticles was around 5 nm, generating a magnetically separable host with high pore volumes and large pores (M-HMMS). α-chymotrypsin (CT) was adsorbed into M-HMMS with high loading (~30 wt%) in less than 30 minutes. Glutaraldehyde (GA) treatment of adsorbed CT resulted in nanometer scale crosslinked enzyme aggregates in M-HMMS (CLEA-M). The activity of these CT aggregates in M-HMMS (CLEA-M-CT) was 34 times than that of simply adsorbed CT in M20 HMMS, due to an effective prevention of enzyme leaching during washing via a ship-in-a-bottle approach. CLEA-M-CT maintained the intial activity not only under shaking (250 rpm) for 30 days, but also under recycled uses of 35 times. The same approach was employed for the synthesis of CLEA-M of lipase (CLEA-M-LP), and proven to be effective in improving the loading, activity, and stability of enzyme when compared to those of adsorbed LP in M-HMMS.
2009. "Clay Nanoparticle-Supported Single-Molecule Fluorescence Spectroelectrochemistry." Nano Letters 9(2):655-658. Abstract We report single-molecule fluorescence spectroelectrochemistry on a clay-modified ITO electrode using cresyl violet as a redox fluorescent probe. Ensemble averaged experiments show that cresyl violet displays well-defined cyclic voltammograms when adsorbed on the clay-modified electrode. By probing the fluorescence intensity of a single cresyl violet molecule absorbed on clay surface, we can trace the redox reaction of individual molecules induced by the cyclic voltammetric potential scanning. Inhomogeneous interfacial electron transfer dynamics of the immobilized single cresyl violet molecules on the clay-modified surface were observed.
2009. "Reduction in biomass burning aerosol light absorption upon humidification: Roles of inorganically-induced hygroscopicity, particle collapse, and photoacoustic heat and mass transfer." Atmospheric Chemistry and Physics 9(22):8949-8966. Abstract Smoke particle emissions from the combustion of biomass fuels typical for the western and southeastern United States were studied and compared under high humidity and ambient conditions in the laboratory. The fuels used are Montana ponderosa pine (Pinus ponderosa), southern California chamise (Adenostoma fasciculatum), and Florida saw palmetto (Serenoa repens). Information on the non-refractory chemical composition of biomass burning aerosol from each fuel was obtained with an aerosol mass spectrometer and through estimation of the black carbon concentration from light absorption measurements at 870 nm. Changes in the optical and physical particle properties under high humidity conditions were observed for hygroscopic smoke particles containing substantial inorganic mass fractions that were emitted from combustion of chamise and palmetto fuels. Light scattering cross sections increased under high humidity for these particles, consistent with the hygroscopic growth measured for 100 nm particles in HTDMA measurements. Photoacoustic measurements of aerosol light absorption coefficients reveal a 20% reduction with increasing relative humidity, contrary to the expectation of light absorption enhancement by the liquid coating taken up by hygroscopic particles. This reduction is hypothesized to arise from two mechanisms: 1. Shielding of inner monomers after particle consolidation or collapse with water uptake; 2. The contribution of mass transfer through evaporation and condensation at high relative humidity to the usual heat transfer pathway for energy release by laser heated particles in the photoacoustic measurement of aerosol light absorption. The mass transfer contribution is used to evaluate the fraction of aerosol surface covered with liquid water solution as a function of RH.
2009. "Methanol Partial Oxidation on MoO3/SiO2 Catalysts: Application of Vibrational Spectroscopic Imaging Techniques in a High Throughput Operando Reactor." Topics in Catalysis 52:1381-1387. Abstract A novel prototype high throughput operando (OHT) reactor designed and built for catalyst screening and characterization is presented in this article. For the first time, this OHT reactor integrates Fourier Transformation infrared (FT-IR) imaging technique and Raman spectroscopy in operando conditions. Using a focal plane array (HgCdTe FPA, 128128 pixels, and 1,675 Hz frame rate) detector for the FT-IR imaging system, we are able to simultaneously follow the catalyst activity and selectivity of all parallel reaction channels. Each set of image data has 16, 384 IR spectra with a spectral range of 900-4000 cm-1 in an 8 cm-1 resolution. It only takes 2-20 second, depending on signal to noise ratio, to collect a full image of all reaction channels. Results on reactant conversion and product selectivity are obtained from FT-IR spectral analysis. Six home-designed Raman probes, one for each reaction channel, are used for simultaneous collection of Raman spectra of all catalysts and possible reaction intermediates on the catalyst surface under real reaction environment. As a model system, methanol partial oxidation reaction on silica supported molybdenum oxide (MoO3/SiO2) catalysts under different reaction conditions has been studied to show the performance of the OHT reactor.
2009. "Nanomaterials for Sensing and Electrocatalysis." Journal of Nanoscience and Nanotechnology 9(4):2173-2174. Abstract This special issue provides an overview of recent advances in nanomaterials for sensing and electrocatalysis. The emergence of nanoscience and nanotechnology has led to great advances in electrochemical science and technology, and these advances may lead to a new branch of electrochemistry research-electrochemical nanotechnology-that combines electrochemical techniques with nanotechnologies to address important issues in energy, electronics, environment, and heath care.
2009. "Stabilization of Metal Nanoparticles in Cubic Mesostructured Silica and Its Application in Regenerable Deep Desulfurization of Warm Syngas." Chemistry of Materials 21(22):5358-5364. Abstract Metal and metal oxide nanoparticles supported on high surface area materials are widely used in industry for fuel and chemical production and for environmental pollution control, but preventing nano-sized particle sintering has remained a great challenge. In this paper, we report that Ni-Cu alloy nanoparticles can be effectively stabilized in cubic mesostructured silica (SBA-16) following a conventional impregnation and thermal treatment process. The three-dimensional interconnected cage structure of the mesoporous SBA-16 allows good accessibility of reactant gas molecules to the metal nanoparticles and confines these particles within its nano-sized cages. This confinement hinders metal nanoparticle migration and sintering under harsh conditions. Based on this strategy, a new class of regenerable metal-based adsorbents which can remove sulfur impurities from warm syngas stream down to less than 60 parts per billion by volume (ppbv) is described. This same confinement strategy is expected to have impact for minimizing sintering or particle coarsening of nano-sized materials employed in other applications.
2009. "Structural and Electronic Properties of Reduced Transistion Metal Oxide Clusters, M3O8 and M3O8- (M=Cr, W), from photoelectron spectroscopy and quantum chemical calculations." Journal of Physical Chemistry A 113(42):11273-11288 . doi:10.1021/jp9082008 Abstract We report a comparative study of reduced transition metal oxide clusters, M3O8- (M = Cr, W) anions and their neutrals, via anion photoelectron spectroscopy (PES) and density functional theory (DFT) and molecular orbital theory (CCSD(T)) calculations. Well-resolved PES spectra are obtained for M3O8- (M = Cr, W) at 193 and 157 nm photon energies. Different PES spectra are observed for M = Cr versus M = W. Extensive DFT and CCSD(T) calculations are performed to locate the ground and low-lying excited states for the neutrals and anions. The ground states of Cr3O8 and Cr3O8- are predicted to be the 3B2 and 4B2 states of a C2v structure, respectively, revealing ferromagnetic spin coupling for Cr 3d electrons. In contrast, the ground states of W3O8 and W3O8- are predicted to be the 1A- state (Cs symmetry) and the 2A1 state (C2v symmetry), respectively, showing strong metal-metal d-d bonding in the anion. The current cluster geometries are in qualitative agreement with prior DFT studies at the PBE level for M = Cr and the B3LYP level for M = W. The BP86 and PW91 functionals significantly outperform the B3LYP functional for the Cr species, in terms of relative energies, electron detachment energies, and electronic excitation energies; whereas the B3LYP functional is better for the W species. In addition, accurate heats of formation for the ground states of M3O8 are calculated from the clustering energies and the heats of formation of MO2 and MO3.
2009. "Structural and Electronic Properties of Reduced Transition Metal Oxide Clusters, M₃O₈ and M₃O₈⁻ (M = Cr, W), from Photoelectron Spectroscopy and Quantum Chemical Calculations." Journal of Physical Chemistry A 113(42):11273-11288. doi:10.1021/jp9082008 Abstract We report a comparative study of reduced transition metal oxide clusters, M₃O₈⁻ (M = Cr, W) anions and their neutrals, via anion photoelectron spectroscopy (PES) and density functional theory (DFT) and molecular orbital theory (CCSD(T)) calculations. Well-resolved PES spectra are obtained for M₃O₈⁻ (M = Cr, W) at 193 and 157 nm photon energies. Different PES spectra are observed for M = Cr versus M = W. ExtensiveDFT and CCSD(T) calculations are performed to locate the ground and low-lying excited states for the neutrals and anions. The ground states of Cr₃O₈ and Cr₃O₈⁻ are predicted to be the ³B₂ and ⁴B₂ states of a C₂v structure, respectively, revealing ferromagnetic spin coupling for Cr 3d electrons. In contrast, the ground states of W₃O₈ and W₃O₈⁻ are predicted to be the ¹A′ state (Cs symmetry) and the ²A₁ state (C₂v symmetry), respectively, showing metal-metal d-d bonding in the anion. The current cluster geometries are in qualitative agreement with prior DFT studies at the PBE level for M = Cr and the B3LYP level for M = W. The BP86 and PW91 functionals significantly outperform the B3LYP functional for the Cr species, in terms of relative energies, electron detachment energies, and electronic excitation energies, whereas the B3LYP functional is better for the W species. Accurate heats of formation for the ground states of M₃O₈ are calculated from the clustering energies and the heats of formation of MO₂ and MO₃. The energetics have been used to predict redox reaction thermochemistry.
2009. "Interparticle Chiral Recognition of Enantiomers: A Nanoparticle-Based Regulation Strategy." Analytical Chemistry 81(2):689-698. doi:10.1021/ac802119p Abstract The ability to regulate how molecular chirality of enantiomeric amino acids operates in biological systems constitutes the basis of drug design for specific targeting of diseases. We report herein nanoparticle-administered chiral recognition of enantiomeric cysteines as a general molecular tuning strategy to regulate the interactions of chiral amino acids. This strategy exploits the pairwise zwitterion interaction of enantiomeric cysteines adsorbed on gold nanoparticles to create a chiral footprint for interparticle enantiomeric recognition. The chiral recognition is evidenced by the sharp kinetic contrast between interparticle homochiral and heterochiral reactivities. The experimental-theoretical correlation of the interparticle reactivity with the enantiomeric ratio reveals that the chiral recognition is tunable both molecularly and by nanoparticles, which has potential applications in drug design for targeting or delivery.
2009. "Microwave Spectrum of the Argon-Tropolone van der Waals Complex." Journal of Physical Chemistry A 113(47):13076-13080. Abstract The rotational spectrum of the argon-tropolone van der Waals complex in the ground vibrational state has been measured in the frequency range of 6 to 17 GHz using a pulsed-jet, Balle-Flygare-type Fourier transform microwave spectrometer. Eighty-six transitions for the complex (Ar-12C7H616O2) were observed, assigned, and fit using a Watson A-reduction Hamiltonian giving the rotational and centrifugal distortion constants A = 1080.4365(3) MHz, B = 883.4943(3) MHz, C = 749.0571(2) MHz, J = 2.591(2) kHz, JK = −3.32(1) kHz, K = 5.232(9) kHz, J = 0.944(1) kHz, and K = −0.028(8) kHz. The tunneling motion of the hydroxyl proton in the tropolone moiety is quenched in the ground electronic state by complexation with argon. The coordinates of the argon atom in the monomer’s principal axis system are a = 0.43 Å, b = 0.23 Å, c = 3.48 Å.
2009. "Low Temperature 65 Cu NMR Spectroscopy of the Cu+ Site in Azurin." Journal of the American Chemical Society 131(39):13992-13999. doi:10.1021/ja901308v Abstract Copper is a ubiquitous component of living systems. It fulfills a vital role in many enzymes, particularly redox enzymes, and more generally in electron transfer. As might be anticipated from the chemistry of the element, the primary redox couple involved in biological redox processes is Cu+/ Cu2+. However, multinuclear copper centers1,2 and mixed metal centers3 give it the ability to participate in multielectron processes. Copper sites in proteins have been classified into several types: type-14 , type-25 , and type-31 copper, as well as the dinuclear CuA center6. Among the best studied are the type-1 sites, characterized by a strong absorbtion in the orange region of the visible spectrum. The blue copper proteins, a class of relatively small, one-electron transfer proteins found in bacteria and plants, notably employs type-1 copper sites.
2009. "Kinetics of Uranium(VI) Desorption from Contaminated Sediments: Effect of Geochemical Conditions and Model Evaluation ." Environmental Science & Technology 43(17):6560-6566. Abstract Stirred-flow cell experiments were performed to investigate the kinetics of uranyl [U(VI)] desorption from a contaminated sediment collected from the Hanford 300 Area at the US Department of Energy (DOE) Hanford Site, Washington. Three influent solutions of variable pH, Ca and carbonate concentrations that affected U(VI) aqueous and surface speciation were used under dynamic flow conditions to evaluate the effect of geochemical conditions on the rate of U(VI) desorption. The measured rate of U(VI) desorption varied with solution chemical composition that evolved as a result of thermodynamic and kinetic interactions between the influent solutions and sediment. The solution chemical composition that led to a lower equilibrium U(VI) sorption to the solid phase yielded a faster desorption rate. The experimental results were used to evaluate a multi-rate, surface complexation model (SCM) that has been proposed to describe U(VI) desorption kinetics in the Hanford sediment that contained complex sorbed U(VI) species in mass transfer limited domains. The model was modified and supplemented by including multi-rate, ion exchange reactions to describe the geochemical interactions between the solutions and sediment. With the same set of model parameters, the modified model reasonably well described the evolution of major ions and the rates of U(VI) desorption under variable geochemical and flow conditions, implying that the multi-rate SCM is an effective way to describe U(VI) desorption kinetics in subsurface sediments.
2009. "Microbial Reduction of Intragrain U(VI) in Contaminated Sediment." Environmental Science & Technology 43(13):4928-4933. doi:10.1021/es8029208 Abstract The accessibility of precipitated, intragrain U(VI) in a contaminated sediment to microbial reduction was investigated to ascertain geochemical and microscopic transport phenomena controlling U(VI) bioavailability. The sediment was collected from the US DOE Hanford site, and contained uranyl precipitates in a form of Na-boltwoodite within the mm-sized granitic lithic fragments in the sediment. Microbial reduction was investigated in a culture of a dissimilatory metal-reducing bacterium (DMRB), Shewanella oneidensis strain MR-1, in bicarbonate solutions at pH 6.8 buffered by PIPES. Measurements of uranium concentration, speciation, and valence in aqueous and solid phases indicated that microbial reduction of intragrain U(VI) proceeded by two mechanisms: 1) sequentially coupled dissolution of intragrain uranyl precipitates, diffusion of dissolved U(VI) out of intragrain regions, and microbial reduction of dissolved U(VI); and 2) U(VI) reduction in the intragrain regions by soluble, diffusible biogenic reductants. The bioreduction rate in the first pathway was over 3 orders of magnitude slower than that in comparable aqueous solutions containing aqueous U(VI) only. The slower bioreduction rate was attributed to: 1) the release of calcium from the desorption/dissolution of calcium-containing minerals in the sediment, which subsequently altered U(VI) aqueous speciation and slowed U(VI) bioreduction and 2) alternative electron transfer pathways that reduced U(VI) in the intragrain regions and changed its dissolution and solubility behavior. The results implied that the overall rate of microbial reduction of intragrain U(VI) will be influenced by the reactive mass transfer of U(VI) and biogenic reductants within intragrain regions, and geochemical reactions controlling major ion concentrations that affect U(VI) aqueous speciation and microbial activity.
2009. "Hygroscopic Properties of CH3SO3Na, CH3SO3NH4, (CH3SO3)2Mg and (CH3SO3)2Ca Particles Studied by Micro-FTIR Spectroscopy." Journal of Physical Chemistry A 113(8):1531-1538. Abstract The hygroscopic behavior of CH3SO3Na, CH3SO3NH4, (CH3SO3)2Mg and (CH3SO3)2Ca particles as a function of relative humidity (RH) has been studied using microscopic Fourier transform infrared (micro-FTIR) spectroscopy. The approach used exposure of substrate deposited, ~1 μm dry-size particles to humidified nitrogen followed by micro-FTIR spectroscopy over a selected sample area. The results show that CH3SO3Na particles undergo characteristic phase transitions at deliquescence relative humidity (DRH) of 71% and efflorescence relative humidity (ERH) of ~40%. In contrast, CH3SO3NH4, (CH3SO3)2Mg and (CH3SO3)2Ca particles do not undergo phase transitions and exhibit continuous, reversible uptake and evaporation of water under the influence of changing RH. The extent of water uptake is quantified and presented as water-to-solute ratios (WSR) in particles as a function of RH. The WSR values are determined from the integrated absorbance of the water and the solute-specific bands in IR spectra recorded at different RH.
2009. "Evaluation of a High Intensity Focused Ultrasound-Immobilized Trypsin Digestion and 18 O-Labeling Method for Quantitative Proteomics." Analytical Chemistry 81(15):6272-6277. Abstract A new method that uses immobilized trypsin concomitant with ultrasonic irradiation results in ultra-rapid digestion and thorough 18O labeling for quantitative protein comparisons. The reproducible and highly efficient method provided effective digestions in <1 min and minimized the amount of enzyme required compared to traditional methods. This method was demonstrated for digestion of both simple and complex protein mixtures, including bovine serum albumin, a global proteome extract from bacteria Shewanella oneidensis, and mouse plasma, as well as for the labeling of complex protein mixtures, which validated the application of this method for differential proteomic measurements. This approach is simple, reproducible, cost effective, and rapid, and thus well-suited for automation.
2009. "Antibody recognition force microscopy shows that outer membrane cytochromes OmcA and MtrC are expressed on the exterior surface of Shewanella oneidensis MR-1." Applied and Environmental Microbiology 75(9):2931-2935. Abstract Antibody-recognition force microscopy showed that OmcA and MtrC are expressed on the exterior surface of living Shewanella oneidensis MR-1 cells during anaerobic growth, when Fe(III) served as the terminal electron acceptor. OmcA was localized to the interface with hematite, while MtrC was more uniformly displayed on the bacterium’s exterior cell surface. Both cytochromes were also found associated with extracellular material.