Subscriber access provided by UniSA Library
Article
In situ monitoring of protein adsorption on a nanoparticulated gold film by attenuated total reflection surface-enhanced infrared absorption spectroscopy Bo Jin, Wen-Jing Bao, Zeng-Qiang Wu, and Xing-Hua Xia Langmuir, Just Accepted Manuscript • DOI: 10.1021/la300819u • Publication Date (Web): 24 May 2012 Downloaded from http://pubs.acs.org on May 31, 2012
Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
Langmuir is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.
Page 1 of 8
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Langmuir
In situ monitoring of protein adsorption on a nanoparticulated gold film by attenuated total reflection surface-enhanced infrared absorption spectroscopy Bo Jin, Wen-Jing Bao, Zeng-Qiang Wu, Xing-Hua Xia* State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China. ABSTRACT: In situ surface enhanced infrared absorption spectroscopy (SEIRAS) with an attenuated total reflection (ATR) configuration has been used to monitor the adsorption kinetics of bovine hemoglobin (BHb) on an Au nanoparticles (NPs) film. The IR absorbance for BHb molecules on gold nanoparticles film deposited on Si hemispherical optical window is about 58 times higher than that on a bare Si optical window and the detection sensitivity has been improved by three orders of magnitude. From the IR signal as function of adsorption time, the adsorption kinetics and thermodynamics can be explored in situ. It is found that both the electrostatic interaction and the coordination bonds between BHb residues and Au NPs film surface affect the adsorption kinetics. The maximum adsorption can be obtained in solution pH 7.0 (closing to the isoelectric point of the protein) due to the electrostatic interaction among proteins. In addition, the isotherm of BHb adsorption follows well the Freundlich adsorption model.
INTRODUCTION Adsorption of proteins with dual hydrophilic and hydrophobic properties on materials surfaces is a common phenomenon which is often encountered in bionanotechnology and has been used to fabricate biosensors, bioelectronics devices and biofuel cells.1 This adsorption process is mainly driven by the weak supermolecular interactions including Van der Waals forces, hydrophilic and hydrophobic interaction, electrostatic interactions and hydrogen bonds, which could cause conformation change and even denaturation of the biomolecules in some cases.2-5 For example, it has been reported that the morphology, chemical structure, electronic property of the surface and interfacial electric field affect the kinetics and mechanism of protein adsorption.6-10 Obviously, understanding of protein adsorption at materials surfaces would help to improve practical performance of bio-chip,11-13 biosensors,14 biological fuel cell,15-22 drug delivery23 and new hybrid materials synthesis.24 Up to now, various methods have been developed to monitor the protein adsorption process at materials sur-
faces, including surface plasmon resonance (SPR),25-27 ellipsometry method,28 quartz crystal microbalance (QCM)9 and electrochemical methods.29 Although these methods are sensitive and can provide the adsorption kinetics of biological molecules, they cannot provide the conformation, orientation and structural information of the immobilized protein molecules at materials surfaces. In addition, these methods are usually affected by the environmental alterations. Infrared spectroscopy has been proved to be a powerful surface analysis technique for identifying the molecular structures. It has been applied to analyze protein secondary structure, i.e., a variety of infrared spectra of proteins adsorbed on germanium surface has been collected by using a FTIR in attenuated total reflection (ATR) mode. 30,31 Surface enhanced infrared absorption spectroscopy (SEIRAS), as an in-situ analysis technology with high sensitivity, has become a powerful tool to study the adsorption/desorption processes, conformation and function of biological molecules occurring at materials surfaces. SEIRAS is usually achieved on a rough noble metal film deposited on silicon prism in the attenuated total reflection mode. The signal enhancement is restricted to the immediate vicinity of the surface and drops exponentially because of the optical near-field effect.32-34 This technique offers an opportunity to monitor the materials surfaces without interference from the environment.35,36 Up to now, SEIRAS-ATR has been successfully applied in qualitative analysis of biological species ranging from small biomolecules to genetic and proteomic targets.37,38 Ataka et al.39 have studied the adsorption behavior of cytochrome c (cyt c) on carboxylic acid and hydroxyl terminated self-assembled monolayers on gold surfaces and found orientation related direct electrochemistry of the immobilized cyt c. Jiang et al.40 have found that the hindrance of electron transfer of adsorbed cyt c on the bare gold electrode was from the adsorption orientations in which most of the helices were parallel to the surface with a flatter orientation of the heme. In this study, a thin gold nanoparticles (NPs) film was deposited on a hemispherical silicon surface via the Galvanic exchange reaction.41-46 The adsorption of bovine hemoglobin (BHb) on this gold film was then monitored
ACS Paragon Plus Environment
Langmuir
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
in situ using the SEIRAS-ATR. The adsorption isotherm of BHb was plotted and fitted by Langmuir adsorption equation and Freundlich adsorption equations. Subsequently, the influence of solution pH on the adsorption kinetics of BHb was studied and the interactions involved in the adsorption process were discussed.
Page 2 of 8
with an average particle size of about 100 nm. The gold nanoparticles are closely packed but yet separated to form numbers of nano-gaps, which is expected to produce large infrared signal enhancement. Another advantage of the chemically deposited Au NPs film is the strong adhesion of the gold NPs to the silicon substrate, because the preformed Si-H bond will facilitate the formation of silicide between Si and Au deposit.49 This property significantly improves the stability of the resultant Au NPs film, as is very important for biomimetic devices. Such nanoparticulated gold films have been reported to produce enhanced IR and Raman scattering signals.42,46 X-ray diffraction characterization shows that the deposited gold film is of typical face centred cubic structure including (111), (200), (220), and (311) orientations at diffraction angle of 38.32o, 44.48o, 65.04o, and 77.86o, respectively (Figure 1c).
EXPERIMENTAL SECTION Materials and reagents: The hemispherical Si (111) ATR prism (36 mm in diameter) was purchased from Alkor Technologies (Russia). Bovine hemoglobin was from Biological Products Corporation (Shanghai, China) and used without further purification. Other reagents were of analytical grade and used as received. All aqueous solutions were prepared using ultrapure water (Milli-Q, Millipore, USA).
IR signal enhancement of the Au nanoparticles film. SEIRAS-ATR spectra of BHb saturation immobilized on a chemically deposited Au NPs film and a bare Si prism were compared to show the signal enhancement caused by the Au NPs film. We can see from Figure 2 that two obvious peaks appear at 1600-1700 cm-1 and 1480-1575 cm-1. The sharp peak at 1654 cm-1 is attributed to the amide I vibration, which is due to the C=O stretching vibrations of the peptide groups.50 The amide II vibration, located at 1546 cm-1, corresponds to the N-H stretching vibration, together with a lesser contribution from the C-N and C=C stretching vibration.50 The secondary structure of protein can be generally obtained from the amide I region as it contains structural information involved in hydrogen bond of peptide chain and is highly sensitive to structural changes. The amide I region of BHb, located at 1654 cm-1, exhibits a typical character shared by α-helix-rich proteins.51 It can be predicted from the spectrum that the secondary structure of BHb adsorbed on the Au NPs film is well maintained. The bands at 1450 cm-1 and 1396 cm-1 are associated with the C-H bending vibration and mixed C-N and C-H bending vibration. The peaks at 1304 cm-1 and 1225 cm-1, named amide III, belong to the combined N-H in-plane bending and C-H stretching vibration.52 We calculated the intensity of amide II vibration, and its intensity on gold NPs film is 58 times larger than that on the Si prism, showing a remarkable enhancement while maintaining the natural structure of BHb.
Deposition of gold nanoparticles film on silicon surface: The hemispherical silicon prism was rinsed by sonication in anhydrous ethanol and ultrapure water respectively after polishing with alumina power (0.3 μm). Native silicon oxide layer was removed by immersing the surface of the silicon prism in 10% HF for 5 min, and then in 40% NH4F for 3 min, followed by rinsing in ultrapure water. This process is known to result in Si-H surfaces. Prior to the deposition, a plating solution containing 0.015M HAuCl4+0.15M Na2SO3+0.05M Na2S2O3+0.05M NH4Cl was prepared.46-48 Deposition of Au nanoparticles film was performed at 60 oC simply by dropping a mixture of 1.0 mL plating solution + 0.5 mL 2% HF onto the hydrogenterminated Si surface and maintained in the dark for 3 min. Ultrapure water was added to end the reaction finally. Instruments: Infrared spectra were measured with a Bruke Tensor27 Fourier transform spectrometer in the attenuated total reflection mode. P-polarized IR radiation was totally reflected at the gold nanoparticles film/solution interface with an incident angle θ=70o and was detected with a liquid-N2-cooled MCT detector. All the spectra were plotted in absorbance unit relative to a baseline which was recorded by immersing the surface in pure buffer for 30 min before further measurement. The O-H stretching of water is automatically subtracted by the IR software. The spectral range was 4000~1000 cm-1 at 4 cm-1 resolution. Atomic force microscopy (AFM) imaging was performed on an Agilent 5500 AFM/SPM system using tapping mode under ambient conditions. Scanning electron microscopy (FE-SEM, S-4800, Hitachi, Japan) at an accelerating voltage of 10 kV was used to characterize the morphology of the deposited gold films. X-ray diffraction pattern was obtained on an X’Pert X-ray diffraction spectrometer (Philips, USA). RESULTS AND DISCUSSION Characterization of Au nanoparticles film. The morphology of the SEIRAS-active Au NPs film was investigated with SEM and AFM. As shown in Figure 1, the chemically deposited gold film has an island structure
2
ACS Paragon Plus Environment
1547 0.0005
1800
1654
1700
1600
1500
Wavenumber /cm
-1
1400
Figure 3． ．The ATR-SEIRA spectrum of 10 nM BHb adsorbed on the Au NPs film in 20 mM PBS at pH 7.0. The time for adsorption was 1 h.
1225 0.04
b ×20 1600
1400-1
1200
0 20 40 60 80 100120140 Time / min
0.02 0.01 0.00
Wavemumber/cm
140 120 100 80 60 40 20
e
1800
0.03
in
Absorbance /o.d.
a
/m
1396 1304 1450
1.2 1.0 0.8 0.6 0.4 0.2 0.0
2000 1900 1800 1700 1600 1500 1400 1300
0
m
1654 1546
-1
0.01
Ti
The deposited Au nanoparticles film not only improves the signal to noise ratio, but also lessens the solution interference. As shown in Figure 3, the amide bonds of BHb from a concentration of 10 nM still can been distinguished after adsorbed for 1 h, while on a bare Si surface, only BHb with a concentration over 3 μM could been detected (not shown). Obviously, the Au NPs film leads to 3 orders of magnitude better detection sensitivity than the bare Si prism.
Integral area (1546cm )
Adsorption kinetics of BHb. The adsorption kinetics of BHb on the Au NPs film surface under neutral condition was monitored by in situ SEIRAS-ATR. Figure 4 shows the evolution of SEIRA spectra as function of adsorption time. The intensity of amide bonds of BHb increases with adsorption time. The amide II vibration of protein is structure-insensitive, so its intensity is usually used to calculate the total quantity of protein.53 Pitt et al.54 reported that the area of amide II peak on a Ge prism had a linear relationship with the amount of dry protein. From this relationship, the amount of proteins adsorbed at the interface could be estimated. In our case, the band area of amide II region centered at 1546 cm-1 was plotted as function of adsorption time (Inset of Figure 4). It is clear that the adsorption kinetics starts very fast at its early stage, then slows down, and finally reaches a steady state. A monolayer of BHb is achieved within about 30 min.
Figure 1． ．(a) SEM image (b) AFM image and (c) X-ray diffraction pattern of the gold NPs film deposited on a silicon o semispherical optical surface at 60 C for 3 min.
Absorbance/o.d.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Langmuir
Absorbance/o.d.
Page 3 of 8
Wavenumber / cm-1
-1
Figure 2． ．The ATR-SEIRA spectra of 0.5 mg•mL BHb in 20 mM PBS (pH 7.0) absorbed on the Au NPs film (a) and a bare Si prism (b) for 1h.
Figure 4． ．Series of ATR-SEIRA spectra for the adsorption of -1 BHb on the Au NPs film from a solution of 0.5 mg•mL BHb + 0.02 M PBS (pH 7.0) at different adsorption time, showing the adsorption process of the protein. Inset shows the plot of -1 the integral for the amide II (1554 cm ) band versus time.
Adsorption isotherm of BHb. Adsorption isotherm is the relationship of distribution between two phases when the adsorption process of a solute reaches equilibrium on
3
ACS Paragon Plus Environment
Langmuir the two-phase interface at a certain temperature, which reflects the nature of interactions between the adsorbates and the surface. All the IR spectra in Figure 5 were collected after adsorption for 30 min, so that all the infrared spectra can be regarded as saturated protein adsorption on the gold nanofilm/solution interface. From Figure 5, it can be clearly seen that the adsorption capacity of BHb on the gold NPs film gains with the increase of protein concentration in solution. However, increase of the adsorption amount of BHb on gold NPs film surface is slightly slower than the increase of protein concentration in solution, indicating that there is no simple quantitative relationship between these two parameters.
1500
1400
Absorbance/o.d.
(1) (2)
1.6
-1
1300
b
1.2
0.8
0.4
0.0 0.0
0.4
0.8
1.2
1.6
-1
2.0
Ce / mg mL
where Ce is the equilibrium concentration of BHb in the solution, qe is the equilibrium adsorption amount of BHb on Au NPs film, qm is the saturated protein adsorption amount, K is the adsorption equilibrium constant, KF and n are constants related with the Au NPs film and BHb at a particular temperature.
Figure 5. (a) The SEIRA-ATR spectra of BHb adsorbed on the Au NPs film from different concentrations of protein. (b) The adsorption isotherm for BHb on Au NPs film.
Seen from Figure 6, the Freundlich fitting equation, with a linear correlation coefficient of 0.998, shows a better agreement with experiment data than the Langmuir fitting results (R2=0.976). Thus, the Freundlich adsorption model considering the interactions among adsorbed molecules and the non-uniformity of adsorption site can give a better description for the adsorption process of BHb on Au NPs film. According to Eq.(2), KF and n can be calculated as 1.20 and 1.50 respectively from the fitting curve, indicating a relatively easy process for BHb adsorption on gold NPs film.
-4.8 1.2
-4.0
-3.2
ln(Ce)
-2.4
-1.6
-0.8
0.0
0.8
Fleundlich
1.0
1.0
Langmuir
a
0.5
0.8
0.0
0.6
-0.5
0.4
-1.0
b
ln(qe)
1 ln Ce n
1600
Wavenumber / cm Integral of amide II( 1554cm-1)
ln qe = ln K F +
0.01
1700
To gain a deep insight into the adsorption process, the results in Figure 5 are simulated by using a Langmuir (Eq.(1)) and Freundlich adsorption models (Eq.(2)) respectively.
Ce 1 1 = + C qe qm K q m e
1.8mg/mL 1.5mg/mL 1.2mg/mL 1.0mg/mL 0.7mg/mL 0.5mg/mL 0.3mg/mL 0.1mg/mL 0.05mg/mL 0.02mg/mL
a
Ce/qe
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 4 of 8
-1.5
0.2
-2.0
0.0 0.0
0.4
0.8
1.2
-1
1.6
2.0
-2.5
Ce/mg⋅mL
Figure 6． ．Plots of surface concentration of BHb on the NPs film as function of solution concentration of the protein simulated by using Langmuir (a, triangles) and Freundlich isotherm (b, cycles).
Influence of solution pH on adsorption behavior of BHb. The protein molecules are mostly non-uniformly charged as the presence of ionized side chains. As a result, the surface charges and their distributions of proteins are related to solution pH values, which will certainly affect the adsorption kinetics if the electrostatic interactions play the determining role. Since the isoelectric point (pI) of BHb is 7.0,55 the protein is positively charged at solution pH lower than the pI, while it is negatively charged at solution pH higher than its pI. 7.0. At pH=pI, the total
4
ACS Paragon Plus Environment
charge of protein will be zero. As shown in Figure 7, significant difference in adsorption kinetics is observed for solution pH=6.0, 7.0 and 8.0 from the normalized IR signal. This difference is mainly due to the alteration in electrostatic interactions between BHb molecules and the gold surface. As we measured before, the potential of zero charge (PZC) of porous Au electrode/PBS is near -0.10V (vs. SCE).56 In the present measurements, protein adsorption was performed at open circuit potential (OCP measured at 0.275V vs. SCE), indicating that surface of Au NPs film carries excess positive charges. Therefore, a fast adsorption kinetics of BHb is observed at solution pH 8.0 due to the electrostatic interactions between negatively charged BHb and the positively charged Au surface. In contrast, with positively charged BHb at pH 6.0, electrostatic repulsion makes the adsorption process slow down, thus longer adsorption time is required to reach adsorption equilibrium.
Absorbance
a
b
pH6.0
0.005
pH7.0
1800 1700 1600 1500 1400 1300 1200 Wavemumber / cm-1
0.005
pH8.0 pH7.0
1800 1700 1600 1500 1400 1300 Wavemumber / cm-1
Figure 8． ．The ATR-SEIRA spectra of the BHb adsorbed on Au NPs film (a) at pH 6.0 (solid) followed by at pH 7.0 (dash); (b) at pH 8.0 (solid) followed by pH 7.0 (dash).
Electrostatic effects not only influence the adsorption rate of proteins, but affect the interaction among proteins as well. As with the same charge, the electrostatic repulsion between BHb may decrease its surface concentration at the nano-film/solution interface. As shown in Figure 8, the infrared spectra of saturation adsorbed BHb at pH 6.0 or pH 8.0 were first recorded. When the pH value of the solution was adjusted to 7.0, an increase in protein signal is observed (Figure 8), indicating that the surface coverage of BHb on gold surface gains as a result of elimination of static interaction among proteins.
100 80
Coverage %
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Langmuir
Absorbance
Page 5 of 8
60 40 20
CONCLUSION In summary, surface enhanced infrared absorption spectroscopy is a sensitive technique for in-situ studying the adsorption process of proteins. The chemically deposited Au nanoparticles on Si surface exhibit good biocompatibility and high enhancement to infrared absorption to proteins. Results show that both the electrostatic interaction and the coordination bonds between BHb residues and Au NPs film surface affect the adsorption kinetics. The maximum adsorption can be obtained in solution pH 7.0. Due to these irreversible interactions and nonuniformed surface structure of gold nanoparticles, the adsorption process of BHb on gold nanoparticles film can be better described by the Freundlich adsorption equation.
0 0
20
40
60
80
100
Time / min
Figure 7． ．Plot of surface coverage of BHb adsorption at various pH versus time; at pH 6.0 (●), pH 7.0 (▲) and pH 8.0 (■). The surface coverage is gained by assuming the saturation adsorption of BHb on the Au NPs film surface to be 100%. The data were obtained by integrating the band area for amide II of the IR spectra.
However, in solution pH 6.0, BHb can still adsorb on the positively charged Au NPs film surface, indicating that there are other primary forces driving the adsorption of BHb. This is confirmed by the fact that desorption of previously adsorbed BHb molecules on the gold nanoparticles film did not occur when we immersed the modified electrode into 1.0 M KCl solution for 3 h. Covalent interaction between Au atom and –NH2/-SH has been widely proven since the lone pair electrons of nitrogen and sulfur atom can be injected into the empty d orbital of Au atom to form weak coordination bonds. Therefore, surfacelocated hydrophilic amino acid residues of BHb, such as Lys, Glu, Cys, His and Arg, make it possible for proteins to interact with the gold surface despite of the existence of electrostatic repulsion.
AUTHOR INFORMATION Corresponding Author *E-mail:
[email protected] (X. H. Xia)
ACKNOWLEDGMENT This work was supported by the Grants from the National 973 Basic Research Program (2012CB933804), the National Natural Science Foundation of China (NSFC, No. 21035002), the National Science Fund for Creative Research Groups (21121091) and the Natural Science Foundation of Jiangsu province (BK2010009).
REFERENCES (1) Nel, A. E.; Mädler, L.; Velegol, D.; Xia, T.; Hoek, E. M. V.; Somasundaran,P.; Klaessig, F.; Castranova, V.; Thompson, M.
5
ACS Paragon Plus Environment
Langmuir
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 6 of 8
Compositions by Scanning Electrochemical Microscopy. Angew. Chem. Int. Ed. 2004, 43, 6355-6357. (21) Kim, H. H.; Zhang, Y. C.; Heller, A. Bilirubin Oxidase Label for an Enzyme-Linked Affinity Assay with O2 as Substrate in a Neutral pH NaCl Solution. Anal. Chem. 2004, 76, 2411-2414. (22) Mano, N.; Fernandez, J. L.; Kim, Y.; Shin, W.; Bard, A. J.; Heller, A. Oxygen Is Electroreduced to Water on a “Wired” Enzyme Electrode at a Lesser Overpotential than on Platinum. J. Am. Chem. Soc. 2003, 125, 15290-15291. (23) Brigger, I.; Dubertnet, C.; Couvreur, P. Nanoparticles in Cancer Therapy and Diagnosis. Adv. Drug Delivery Rev. 2002, 54, 631-651. (24) Srivastava, S.; Verma, A.; Frankamp, B. L.; Rotello, V. M. Controlled Assembly of Protein–Nanoparticle Composites through Protein Surface Recognition. Adv. Mater. 2005, 17, 617621. (25) Höök, F.; Kasemo, B.; Nylander, T.; Fant, C.; Sott, K.; Elwing, H. Variations in Coupled Water, Viscoelastic Properties, and Film Thickness of a Mefp-1 Protein Film during Adsorption and Cross-Linking: A Quartz Crystal Microbalance with Dissipation Monitoring, Ellipsometry, and Surface Plasmon Resonance Study. Anal. Chem. 2001, 73, 5796-5804. (26) Sigal, G. B.; Marksich, M.; Whitesides, G. M. Effect of Surface Wettability on the Adsorption of Proteins and Detergents. J. Am. Chem. Soc. 1998, 120, 3464-3473. (27) Green, R. J.; Davies, J.; Davies, M. C.; Roberts C. J.; Tendler, S. J. B. Surface Plasmon Resonance for Real Time in situ Analysis of Protein Adsorption to Polymer Surfaces. Biomaterials 1997, 18, 405-413. (28) Rechendorff, K.; Hovgaard, M. B.; Foss, M.; Zhdanov, V. P.; Besenbacher, F. Enhancement of Protein Adsorption Induced by Surface Roughness. Langmuir 2006, 22, 10885-10888. (29) Jackson, D. R.; Omanovic, S.; Roscoe, S. G. Electrochemical Studies of the Adsorption Behavior of Serum Proteins on Titanium. Langmuir 2000, 16, 5449-5457. (30) Smith, B. M.; Oswald, L.; Franzen, S. Single-Pass Attenuated Total Reflection Fourier Transform Infrared Spectroscopy for the Prediction of Protein Secondary Structure. Anal. Chem. 2002, 74, 3386-3391. (31) Smith, B. M.; Franzen, S. Single-Pass Attenuated Total Reflection Fourier Transform Infrared Spectroscopy for the Analysis of Proteins in H2O Solution. Anal. Chem. 2002, 74, 4076-4080. (32) Osawa, M. Dynamic Processes in Electrochemical Reactions Studied by Surface-Enhanced Infrared Absorption Spectroscopy(SEIRAS). Bull. Chem. Soc. Jpn. 1997, 70, 2861-2880. (33) Lin, W.; Li, Z. J. Detection and Quantification of Trace Organic Contaminants in Water Using the FT-IR-Attenuated Total Reflectance Technique. Anal. Chem. 2010, 82, 505-515. (34) Ataka, K.; Kottke, T.; Heberle, J. Thinner, Smaller, Faster: IR Techniques To Probe the Functionality of Biological and Biomimetic Systems. Angew. Chem. Int. Ed. 2010, 49, 5416-5424. (35) Ataka, K.; Heberle, J. Biochemical Applications of Surface-Enhanced Infrared Absorption Spectroscopy. Anal. Bioanal. Chem. 2007, 388, 47-54. (36) Chittur, K. K. FTIR/ATR for Protein Adsorption to Biomaterial Surfaces. Biomaterials 1998, 19, 357-369. (37) Osawa, M.; Hasegawa, T. Vibrational Spectroscopy at Surfaces and Interfaces. Anal. Bioanal. Chem. 2007, 388, 5-6. (38) Jiang, X.; Zaitseva, E.; Schmidt, M.; Siebert, F.; Engelhard, M.; Schlesinger, R.; Ataka, K.; Vogel, R.; Heberle, J. Proc. Natl. Acad. Sci. U.S.A. 2008, 105, 12113. (39) Ataka, K.; Heberle J. Functional Vibrational Spectroscopy of a Cytochrome c Monolayer: SEIDAS Probes the Interaction
Understanding Biophysicochemical Interactions at the Nano–bio Interface. Nat. Mater. 2009, 8, 543-557. (2) Fukuda, K.; Ohno, H. Electron Transfer Reaction of Cytochrome c at the Electrode Surface Analyzed with Noncontact Optical Waveguide Spectroscopy. Electroanalysis. 2002, 14, 605610. (3) Andrade, J. D.; Hlady, V. Protein Adsorption and Materials Biocompatibility – A Tutorial Review and Suggested Hypotheses. Adv. Polym. Sci. 1986, 79, 1-63. (4) Du, Y. Z.; Saavedra, S. S. Molecular Orientation Distribution in protein Films. V. Cytochrome c Adsorbed to a SulfonateTerminated, Self-Assembled Monolayer. Langmuir. 2003, 19, 6443-6448. (5) Holmlin, R. E.; Chen, X. X.; Chapman, R. G.; Takayama, S.; Whitesides, G. M. Zwitterionic SAMs that Resist Nonspecific Adsorption of Protein from Aqueous Buffer. Langmuir. 2001, 17, 2841-2850. (6) Song, Y. Y.; Jia, W. Z.; Li, Y.; Xia, X. H.; Wang, Q. J.; Zhao, J. W.; Yan,Y. D. Synthesis and Patterning of Prussian Blue Nanostructures on Silicon Wafer via Galvanic Displacement Reaction. Adv. Funct. Mater. 2007, 17, 2808-2814. (7) Song,Y. Y.; Li, Y.; Wang, X. F.; Xia, X. H. Surface Electric Field Manipulation of the Adsorption Kinetics and Biocatalytic Properties of Cytochorme c on a 3D Macroporous Au Electrode. Anal. Bioanal. Chem. 2008, 390, 333-341. (8) Wang, C. H.; Kong, Y. B.; Xia, X. H. Influence of Electric Field on the Adsorption and Bioactivity of Hemoglobin on A Macroporous Gold Electrode. J. Electrochem. 2011, 17, 24-30. (9) Roach, P.; Farrar, D.; Perry, C. P. Interpretation of Protein Adsorption: Surface-Induced Conformational Changes. J. Am. Chem. Soc. 2005, 127, 8168-8173. (10) Roach, P.; Farrar, D.; Perry, C. P. Surface Tailoring for Controlled Protein Adsorption: Effect of Topography at the Nanometer Scale and Chemistry. J. Am. Chem. Soc. 2006, 128, 39393945. (11) Lee, Y. S.; Mrkish, M. Protein Chips: from Concept to Practice. Trends Biotechnol. 2002, 20, 14-18. (12) Zhu, H.; Snyder, M. Protein Chip Technology. Curr. Opin. Chem. Biol. 2003, 7, 55-63. (13) Drummond, T. G.; Hill, M. G.; Barton, J. K. Electrochemical DNA Sensors. Nat. Biotechnol. 2003, 21, 1192-1199. (14) Nam, J. M.; Thaxton, C. S.; Mirkin, C. A. NanoparticleBased Bio-Bar Codes for the Ultrasensitive Detection of Proteins. Science. 2003, 301, 1884-1886. (15) Willner, I.; Arad, G.; Katz, E. A Biofuel Cell Based on Pyrroloquinoline Quinone and Microperoxidase-11 Monolayerfunctionalized Electrodes. Bioelectrochem. Bioenerg. 1998, 44, 209-214. (16) Willner, I.; Katz, E.; Patolsky, F.; Bückmann, A. F. Biofuel Cell Based on Glucose Oxidase and Microperoxidase-11 Monolayer-Functionalized Electrodes. J. Chem. Soc., Perkin Trans. 1998, 2, 1817-1822. (17) Lioubashevski, O.; Chegel, V. I.; Patolsky, F.; Katz, E.; Willner, I. Enzyme-Catalyzed Bio-Pumping of Electrons into AuNanoparticles: A Surface Plasmon Resonance and Electrochemical Study. J. Am. Chem. Soc. 2004, 126, 7133-7143. (18) Katz, E.; Sheeney-Haj-Ichia, L.; Willner, I. Electrical Contacting of Glucose Oxidase in a Redox-Active Rotaxane Configuration. Angew. Chem. Int. Ed. 2004, 43, 3292-3300. (19) Mano, N.; Heller, A. Detection of Glucose at 2 fM Concentration. Anal. Chem. 2005, 77, 729-732. (20) Fernandez, J. L.; Mamo, N.; Mao, F.; Heller, A.; Bard, A. J. Optimization Of “Wired” Enzyme O2-Electroreduction Catalyst
6
ACS Paragon Plus Environment
Page 7 of 8
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Langmuir (56) Song, Y. Y.; Yang, C.; Xia, X. H. Template-Synthesized Protein Macroporous Biofilms Electrode: Conformational Related Electron Transfer. Adv. Funct. Mater. 2007, 17, 2377-2384.
with Different Surface-Modified Electrodes. J. Am. Chem. Soc. 2004, 126, 9445-9457. (40) Lin, S. R.; Jiang, X.; Wang, L. X.; Li, G. H.; Guo, L. P. Adsorption Orientation of Horse Heart Cytochrome c on a Bare Gold Electrode Hampers Its Electron Transfer. J. Phys. Chem. C 2012, 116, 637–642. (41) Song, Y. Y.; Gao, Z. D.; Kelly, J. J.; Xia, X. H. Galvanic Deposition of Nanostructured Noble-Metal Films on Silicon. Electrochem. Solid-State Lett. 2005, 10, 148-150. (42) Wang, C. H.; Sun, D. C.; Xia, X. H. One-step Formation of Nanostructured Gold Layers via a Galvanic Exchange Reaction for Surface Enhancement Raman Scattering. Nanotechnology. 2006, 17, 651-657. (43) Shi, F.; Song, Y. Y.; Niu, J.; Xia, X. H.; Wang, Z. Q.; Zhang, X. Facile Method To Fabricate a Large-Scale Superhydrophobic Surface by Galvanic Cell Reaction. Chem. Mater. 2006, 18, 13651368. (44) Wang, C. H.; Song, Y. Y.; Zhao, J. W.; Xia, X. H. Semiconductor Supported Biomimetic Superhydrophobic Gold Surfaces by the Galvanic Exchange Reaction. Surf. Sci. 2006, 600, 38-42. (45) Song, Y. Y.; Jia, W. Z.; Li, Y.; Xia, X. H.; Wang, Q. J.; Zhao, J. W.; Yan, Y. D. Synthesis and Patterning of Prussian Blue Nanostructures on Silicon Wafer via Galvanic Displacement Reaction. Adv. Funct. Mater. 2007, 17, 2808-2814. (46) Miyake, H.; Ye, S.; Osawa, M. Electroless Deposition of Gold Thin Films on Silicon for Surface-Enhanced Infrared Spectroelectrochemistry. Electrochem. Commun. 2002, 4, 973-977. (47) Yan, Y. G.; Li, Q. X.; Huo, S. J.; Sun, Y. N.; Cai, W. B. Surface-enhanced IR Absorption Effect of Pt and Ru Nanofilms Fabricated by All-wet Processes. Acta Chimica Sinica 2005, 63, 545549. (48) Huo, S. J.; Xue, X. K.; Yan, Y. G.; Li, Q. X.; Ma, M.; Cai, W. B.; Xu, Q. J.; Osawa, M. Extending in Situ Attenuated-TotalReflection Surface-Enhanced Infrared Absorption Spectroscopy to Ni Electrodes. J. Phys. Chem. B 2006, 110, 4162-4169. (49) Landree, E.; Grozea, D.; Collazo-Davila, C.; Marks, L. D. UHV High-Resolution Electron Microscopy and Chemical Analysis of Room-Temperature Au Deposition on Si(001)-2×1. Phys. Rev.B 1997, 55, 7910-7916. (50) Moulton, S. E.; Barisci, J. N.; McQuillan, A. J.; Wallace, G. G. ATR-IR Spectroscopic Studies of the Influence of Phosphate Buffer on Adsorption of Immunoglobulin G to TiO2. Colloids Surf., A. 2003, 220, 159-167. (51) Buijs, J.; Norde, W.; Lichtenbelt, J. W. Changes in the Secondary Structure of Adsorbed IgG and F(ab‘)2 Studied by FTIR Spectroscopy. Langmuir. 1996, 12, 1605-1613. (52) Cai, S. W.; Singh, B. R. A Distinct Utility of the Amide III Infrared Band for Secondary Structure Estimation of Aqueous Protein Solutions Using Partial Least Squares Methods. Biochemistry. 2004, 43, 2541-2549. (53) Joen, J. S.; Sperline, R. P.; Raghavan, S. Quantitative Analysis of Adsorbed Serum Albumin on Segmented Polyurethane Using FT-IR/ATR Spectroscopy. Appl. Spectrosc. 1992, 46, 16441648. (54) Pitt, W. G.; Cooper, S. L.In Proteins at interfaces: physicochemical and biochemical studies; Brash, J. L., Horbett, T. A., Eds.; ACS Symposium Series 343; American Chemical Society: Washington, DC, 1987. (55) Lvov, Y.; Ariga, K.; Ichinose, I.; Kunitake, T. Molecular Film Assembly via Layer-by-Layer Adsorption of Oppositely Charged Macromolecules (Linear Polymer, Protein and Clay) and Concanavalin A and Glycogen. Thin Solid Films. 1996, 284, 797-801.
7
ACS Paragon Plus Environment
Langmuir
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
ATR-SEIRA
d E
8
ACS Paragon Plus Environment
Page 8 of 8
