Name: interfacial molecular-level structures of polymers and biomacromolecules revealed via sum frequency generation vibrational spectroscopy
Uploaded: 2019-08-13T13:30:00
Description: Watch this Scientific Journal Video about Interfacial Molecular-level Structures of Polymers and Biomacromolecules Revealed via Sum Frequency Generation Vibrational Spectroscopy at JoVE.com

这项研究得到了国家基础研究重点发展计划(2017YFA0700500)和国家自然科学基金(21574020)的支持。中央高校基础研究基金,由江苏省高等学校重点学术项目开发项目和国家实验生物医学工程示范中心资助教育(东南大学)也受到高度赞赏。

1. SFG实验
<ol><li>使用商用皮秒 SFG 系统 (材料表),它基于 Nd:YAG 激光提供脉冲宽度为 ±20 ps 和 50 Hz 频率的基本 1064 nm 光束。</li>
	<li>通过使用第二和第三谐波模块,将基本 1064 nm 光束转换为 532 nm 光束和 355 nm 光束。直接引导 532 nm 光束作为输入光束,并通过光学参数生成 (OPG)/光学参数放大 (OPA)生成其他输入中红外 (IR) 光束,覆盖频率范围从 1000 到 4000 厘米-1)差频生成 (...

<ol>
	<li>Shen, Y. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optical+Second+Harmonic+Generation+at+Interfaces.">Optical Second Harmonic Generation at Interfaces.</a> Annual Review of Physical Chemistry. 40, 327-350 (1989).</li><li>Shen, Y. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surface+properties+probed+by+second-harmonic+and+sum-frequency+generation.">Surface properties probed by second-harmonic and sum-frequency generation.</a> Nature. 337, 519-525 (1989).</li><li>Lu, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Studying+Polymer+Surfaces+and+Interfaces+with+Sum+Frequency+Generation+Vibrational+Spectroscopy.">Studying Polymer Surfaces and Interfaces with Sum Frequency Generation Vibrational Spectroscopy.</a> Analytical Chemistry. 89 (1), 466-489 (2017).</li><li>Chen, X., Clarke, M. L., Wang, J., Chen, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sum+Frequency+Generation+Vibrational+Spectroscopy+Studies+on+Molecular+Conformation+and+Orientation+of+Biological+Molecules+at+Interfaces.">Sum Frequency Generation Vibrational Spectroscopy Studies on Molecular Conformation and Orientation of Biological Molecules at Interfaces.</a> International Journal of Modern Physics B. 19 (4), 691-713 (2005).</li><li>Eisenthal, K. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Liquid+Interfaces+Probed+by+Second-Harmonic+and+Sum-Frequency+Spectroscopy.">Liquid Interfaces Probed by Second-Harmonic and Sum-Frequency Spectroscopy.</a> Chemical Reviews. 96 (4), 1343-1360 (1996).</li><li>Richmond, G. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molcular+Bonding+and+Interactions+at+Aqueous+Surfaces+as+Probed+by+Vibrational+Sum+Frequency+Spectroscopy.">Molcular Bonding and Interactions at Aqueous Surfaces as Probed by Vibrational Sum Frequency Spectroscopy.</a> Chemical Reviews. 102 (8), 2693-2724 (2002).</li><li>Wang, H., Gan, W., Lu, R., Rao, Y., Wu, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+spectral+and+orientational+analysis+in+surface+sum+frequency+generation+vibrational+spectroscopy(SFG-VS).">Quantitative spectral and orientational analysis in surface sum frequency generation vibrational spectroscopy(SFG-VS).</a> International Reviews in Physical Chemistry. 24 (2), 191-256 (2007).</li><li>Shultz, M. J., Schnitzer, C., Simonelli, D., Baldelli, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sum+frequency+generation+spectroscopy+of+the+aqueous+interface:+Ionic+and+soluble+molecular+solutions.">Sum frequency generation spectroscopy of the aqueous interface: Ionic and soluble molecular solutions.</a> International Reviews in Physical Chemistry. 19 (1), 123-153 (2010).</li><li>Li, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detecting+Surface+Hydration+of+Poly(2-hydroxyethyl+methacrylate)+in+Solution+in+situ.">Detecting Surface Hydration of Poly(2-hydroxyethyl methacrylate) in Solution in situ.</a> Macromolecules. 49, 3116-3125 (2016).</li><li>Li, X., Lu, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evolution+of+Irreversibly+Absorbed+Layer+Promotes+Dewetting+of+Polystyrene+Film+on+Sapphire.">Evolution of Irreversibly Absorbed Layer Promotes Dewetting of Polystyrene Film on Sapphire.</a> Macromolecules. 51, 6653-6660 (2018).</li><li>Lu, X., Spanninga, S. A., Kristalyn, C. B., Chen, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surface+Orientation+of+Phenyl+Groups+in+Poly(sodium+4-styrenesulfonate)+and+in+Poly(sodium+4-styrenesulfonate):+Poly(3,4-ethylenedioxythiophene)+Mixture+Examined+by+Sum+Frequency+Generation+Vibrational+Spectroscopy.">Surface Orientation of Phenyl Groups in Poly(sodium 4-styrenesulfonate) and in Poly(sodium 4-styrenesulfonate): Poly(3,4-ethylenedioxythiophene) Mixture Examined by Sum Frequency Generation Vibrational Spectroscopy.</a> Langmuir. 26 (17), 14231-14235 (2010).</li><li>Lu, X., Clarke, M. L., Li, D., Wang, X., Chen, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Sum+Frequency+Generation+Vibrational+Study+of+the+Interference+Effect+in+Poly(n-butyl+methacrylate)+Thin+Films+Sandwiched+between+Silica+and+Water.">A Sum Frequency Generation Vibrational Study of the Interference Effect in Poly(n-butyl methacrylate) Thin Films Sandwiched between Silica and Water.</a> Journal of Physical Chemistry C. 115, 13759-13767 (2011).</li><li>Lu, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Directly+Probing+Molecular+Ordering+at+the+Buried+Polymer/Metal+Interface+2:+Using+P-Polarized+Input+Beams.">Directly Probing Molecular Ordering at the Buried Polymer/Metal Interface 2: Using P-Polarized Input Beams.</a> Macromolecules. 45, 6087-6094 (2012).</li><li>Lu, X., Myers, J. N., Chen, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+Ordering+of+Phenyl+Groups+at+the+Buried+Polystyrene/Metal+Interface.">Molecular Ordering of Phenyl Groups at the Buried Polystyrene/Metal Interface.</a> Langmuir. 30, 9418-9422 (2014).</li><li>Li, B., Lu, X., Ma, Y., Han, X., Chen, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Method+to+Probe+Glass+Transition+Temperatures+of+Polymer+Thin+Films.">Method to Probe Glass Transition Temperatures of Polymer Thin Films.</a> ACS Macro Letters. 4, 548-551 (2015).</li><li>Li, X., Deng, G., Ma, L., Lu, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interchain+Overlap+Affects+Formation+of+Silk+Fibroin+Secondary+Structure+on+Hydrophobic+Polystyrene+Surface+Detected+via+Achiral/Chiral+Sum+Frequency+Generation.">Interchain Overlap Affects Formation of Silk Fibroin Secondary Structure on Hydrophobic Polystyrene Surface Detected via Achiral/Chiral Sum Frequency Generation.</a> Langmuir. 34, 9453-9459 (2018).</li><li>Kai, S., Li, X., Li, B., Han, X., Lu, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Calcium-dependent+hydrolysis+of+supported+planar+lipids+was+triggered+by+honey+bee+venom+phospholipase+A2+with+the+right+orientation+at+the+interface.">Calcium-dependent hydrolysis of supported planar lipids was triggered by honey bee venom phospholipase A2 with the right orientation at the interface.</a> Physical Chemistry Chemical Physics. 20, 63-67 (2018).</li><li>Wang, J., Buck, S., Chen, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sum+Frequency+Generation+Vibrational+Spectroscopy+Studies+on+Protein+Adsorption.">Sum Frequency Generation Vibrational Spectroscopy Studies on Protein Adsorption.</a> Journal of Physical Chemistry B. 106, 11666-11672 (2002).</li><li>Wang, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detection+of+Amide+I+Signals+of+Interfacial+Proteins+in+Situ+Using+SFG.">Detection of Amide I Signals of Interfacial Proteins in Situ Using SFG.</a> Journal of American Chemical Society. 125, 9914-9915 (2003).</li><li>Nguyen, K. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Probing+the+Spontaneous+Membrane+Insertion+of+a+Tall-Anchored+Membrane+Protein+by+Sum+Frequency+Generation+Spectroscopy.">Probing the Spontaneous Membrane Insertion of a Tall-Anchored Membrane Protein by Sum Frequency Generation Spectroscopy.</a> Journal of American Chemistry Society. 132, 15112-15115 (2010).</li><li>Li, X., Ma, L., Lu, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Calcium+Ions+Affect+Water+Molecular+Structures+Surrounding+an+Oligonucleotide+Duplex+as+Revealed+by+Sum+Frequency+Generation+Vibrational+Spectroscopy.">Calcium Ions Affect Water Molecular Structures Surrounding an Oligonucleotide Duplex as Revealed by Sum Frequency Generation Vibrational Spectroscopy.</a> Langmuir. , (2018).</li><li>Sartenaer, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sum-frequency+generation+spectroscopy+of+DNA+monolayers.">Sum-frequency generation spectroscopy of DNA monolayers.</a> Biosensors &amp; Bioelectronics. 22, 2179-2183 (2007).</li><li>Asanuma, H., Noguchi, H., Uosaki, K., Yu, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Metal+Cation-induced+Deformation+of+DNA+Self-Assembled+Monolayers+on+Silicon:+Vibrational+Sum+Frequency+Generation+Spectroscopy.">Metal Cation-induced Deformation of DNA Self-Assembled Monolayers on Silicon: Vibrational Sum Frequency Generation Spectroscopy.</a> Journal of American Chemistry Society. 130, 8016-8022 (2008).</li><li>Howell, C., Schmidt, R., Kurz, V., Koelsch, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sum-frequency-generation+spectroscopy+of+DNA+films+in+air+and+aqueous+environments.">Sum-frequency-generation spectroscopy of DNA films in air and aqueous environments.</a> Biointerphases. 3 (3), FC47 (2008).</li><li>Walter, S. R., Geiger, F. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=DNA+on+Stage:+Showcasing+Oligonucleotides+at+Surfaces+and+Interfaces+with+Second+Harmonic+and+Vibrational+Sum+Frequency+Generation.">DNA on Stage: Showcasing Oligonucleotides at Surfaces and Interfaces with Second Harmonic and Vibrational Sum Frequency Generation.</a> Journal of Physical Chemistry Letters. 1, 9-15 (2010).</li><li>Li, Z., Weeraman, C., Azam, M. S., Osman, E., Gibbs-Davis, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+thermal+reorganization+of+DNA+immobilized+at+the+silica/buffer+interface:+a+vibrational+sum+frequency+generation+investigation.">The thermal reorganization of DNA immobilized at the silica/buffer interface: a vibrational sum frequency generation investigation.</a> Physical Chemistry Chemical Physics. 17, 12452-12457 (2015).</li><li>Lambert, A. G., Neivandt, D. J., Briggs, A. M., Usadi, E. W., Davies, P. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interference+Effects+in+Sum+Frequency+Spectra+from+Monolayers+on+Composite+Dielectric/Metal+Substrates.">Interference Effects in Sum Frequency Spectra from Monolayers on Composite Dielectric/Metal Substrates.</a> Journal of Physical Chemistry B. 106, 5461-5469 (2002).</li><li>Tong, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interference+effects+in+the+sum+frequency+generation+spectra+of+thin+organic+films.+I.+Theoretical+modeling+and+simulation.">Interference effects in the sum frequency generation spectra of thin organic films. I. Theoretical modeling and simulation.</a> Journal of Chemical Physics. 133, 034704 (2010).</li><li>McGall, S. J., Davies, P. B., Neivandt, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interference+Effects+in+Sum+Frequency+Vibrational+Spectra+of+Thin+Polymer+Films:+An+Experimental+and+Modeling+Investigation.">Interference Effects in Sum Frequency Vibrational Spectra of Thin Polymer Films: An Experimental and Modeling Investigation.</a> Journal of Physical Chemistry B. 108, 16030-16039 (2004).</li><li>Li, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interfacial+Fresnel+Coefficients+and+Molecular+Structures+of+Model+Cell+Membranes:+From+a+Lipid+Monolayer+to+a+Lipid+Bilayer.">Interfacial Fresnel Coefficients and Molecular Structures of Model Cell Membranes: From a Lipid Monolayer to a Lipid Bilayer.</a> Journal of Physical Chemistry C. 118, 28631-28639 (2014).</li><li>Zhou, J., Anim-Danso, E., Zhang, Y., Zhou, Y., Dhinojwala, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interfacial+Water+at+Polyurethane-Sapphire+Interface.">Interfacial Water at Polyurethane-Sapphire Interface.</a> Langmuir. 31 (45), 12401-12407 (2015).</li><li>Gautam, K. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+Structure+of+Polystyrene+at+Air/Polymer+and+Solid/Polymer+Interfaces.">Molecular Structure of Polystyrene at Air/Polymer and Solid/Polymer Interfaces.</a> Physical Review Letters. 85 (18), 3854-3857 (2000).</li><li>Yan, E. Y., Fu, L., Wang, Z., Liu, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biological+Macromolecules+at+Interfaces+Probed+by+Chiral+Vibrational+Sum+Frequency+Generation+Spectroscopy.">Biological Macromolecules at Interfaces Probed by Chiral Vibrational Sum Frequency Generation Spectroscopy.</a> Chemical Reviews. 114, 8471-8498 (2014).</li><li>Belkin, M. A., Kulakov, T. A., Ernst, K. H., Yan, L., Shen, Y. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sum-Frequency+Vibrational+Spectroscopy+on+Chiral+Liquids:+A+Novel+Technique+to+Probe+Molecular+Chirality.">Sum-Frequency Vibrational Spectroscopy on Chiral Liquids: A Novel Technique to Probe Molecular Chirality.</a> Physical Review Letters. 85, 4474 (2000).</li><li>Rockwood, D. N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Materials+fabrication+from+Bombyx+mori+silk+fibroin.">Materials fabrication from Bombyx mori silk fibroin.</a> Nature Protocols. 6, 1612-1631 (2011).</li></ol>

为了从分子水平上研究结构信息,SFG 具有其固有的优势(即单层或亚单层灵敏度和界面选择性),可用于研究各种接口,如固体/固体、固体/液体、固体/气体、液体/气体、液体/液体接口。尽管设备维护和光学校准仍然耗时,但回报显著,因为可以在表面和接口上获得详细的分子级信息。
探测聚物(2-羟基乙二甲酸酯)溶液中的表面和埋藏界面:如上文所示,可以调整光场系数。我们?...

总频率生成(SFG)振动光谱的发展可以追溯到沈等人30年前1、2年所做的工作。界面选择性和亚单层灵敏度的独特性使SFG振动光谱学受到物理学、化学、生物学和材料科学等领域大量研究人员的赞赏,3,4 , 5.目前,使用SFG正在研究与表面和界面相关的广泛科学问题,特别是与聚合物和生物大分子相关的复杂界面,如链结构和结构松弛。埋藏聚合物界面,蛋白质二级结构,和界面水结构9,10,11,12,13,14, 15,16,17,18,19,20,21,22,23 24,25,26.
对于聚合物表面和界面,通常通过自旋涂层制备薄膜样品,以获得所需的表面或界面。问题产生是由于信号干扰从两个接口的制备薄膜,这导致不便分析收集的SFG光谱27,28,29 。在大多数情况下,振动信号仅来自单个接口,无论是薄膜/基板还是薄膜/另一种介质,都是可取的。实际上,解决这个问题的方法很简单,即实验性地最大化理想界面的光场,并尽量减少另一个界面的光场。因此,菲涅尔系数或局部场系数需要通过薄膜模型计算,并结合实验结果3、9、10、11进行验证。 12,13,14,15,30。
考虑到上述背景,可以研究一些聚合物和生物界面,以便从分子水平上了解基础科学。在以下,以三个界面问题为例:探测聚聚物(2-羟基乙二醇丙烯酸酯)表面和埋藏界面与基板9,在聚苯乙烯(PS)表面形成丝纤维素(SF)二级结构,水结构周围的模型短链寡核苷酸双工16,21,我们将展示SFG振动光谱如何帮助揭示与基础科学相关的界面分子级结构。

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC)&#160;</td>
			<td>Avanti Polar Lipids, Inc.</td>
			<td>850355P-1g</td>
			<td></td>
		</tr>
		<tr>
			<td>Anhydrous ethanol</td>
			<td>Sinopharm Chemical Reagent Co., Ltd</td>
			<td>100092680</td>
			<td>&#8805;99.7%</td>
		</tr>
		<tr>
			<td>CaF2 prism</td>
			<td>Chengdu YaSi Optoelectronics Co., Ltd.</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Calcium chloride anhydrous</td>
			<td>Sinopharm Chemical Reagent Co., Ltd</td>
			<td>10005817</td>
			<td>&#8805;96.0%</td>
		</tr>
		<tr>
			<td>deuterated DPPC (d-DPPC)</td>
			<td>Avanti Polar Lipids, Inc.</td>
			<td>860345P-100mg</td>
			<td></td>
		</tr>
		<tr>
			<td>Electromagnetic oven</td>
			<td>Zhejiang Supor Co., Ltd</td>
			<td>C21-SDHCB37</td>
			<td></td>
		</tr>
		<tr>
			<td>Langmuir-Blodgett (LB) trough</td>
			<td>KSV NIMA Co., Ltd.</td>
			<td>KN 2003</td>
			<td></td>
		</tr>
		<tr>
			<td>Lithium bromide anhydrous</td>
			<td>Sinopharm Chemical Reagent Co., Ltd</td>
			<td>20056926</td>
			<td></td>
		</tr>
		<tr>
			<td>Milli-Q synthesis system</td>
			<td>Millipore</td>
			<td></td>
			<td>Ultrapure water</td>
		</tr>
		<tr>
			<td>Plasma cleaner</td>
			<td>Chengdu Mingheng Science&#38;Technology Co., Ltd</td>
			<td>PDC-MG</td>
			<td>Oxygen plasma cleaning</td>
		</tr>
		<tr>
			<td>Poly(2-hydroxyethyl methacrylate) (PHEMA)</td>
			<td>Sigma-Aldrich Co., LLC.</td>
			<td>192066 MSDS</td>
			<td>Mw = 300 000</td>
		</tr>
		<tr>
			<td>Polystyrene</td>
			<td>Sigma-Aldrich Co., LLC.</td>
			<td>330345 MSDS</td>
			<td>Mw = 48 kDa and Mn = 47 kDa</td>
		</tr>
		<tr>
			<td>Silk cocoons</td>
			<td></td>
			<td></td>
			<td>From Bombyx mori</td>
		</tr>
		<tr>
			<td>Single complementary strand of oligonucleotide</td>
			<td>Nanjing Genscript Biotechnology Co., Ltd.</td>
			<td>H03596</td>
			<td>5&#39;-CGAAGGCTTCCAGCT-3&#39;</td>
		</tr>
		<tr>
			<td>Single strand of oligonucleotide</td>
			<td>Nanjing Genscript Biotechnology Co., Ltd.</td>
			<td>H04936</td>
			<td>&#160;3&#162;-end modified by cholesterol-triethylene glycol(Chol-TEG) (5&#162;-GCTTCCGAAGGTCGA-3&#162;)</td>
		</tr>
		<tr>
			<td>Sodium carbonate anhydrous</td>
			<td>Sinopharm Chemical Reagent Co., Ltd</td>
			<td>10019260</td>
			<td>&#8805;99.8%</td>
		</tr>
		<tr>
			<td>Spin-coater</td>
			<td>Institute of Microelectronics of the Chinese Academy of Sciences</td>
			<td>KW-4A</td>
			<td>For the prepartion of ploymer films&#160;</td>
		</tr>
		<tr>
			<td>Step profiler</td>
			<td>Veeco</td>
			<td>DEKTAK 150</td>
			<td>For the measurement of film thickness</td>
		</tr>
		<tr>
			<td>Sum frequency generation (SFG) vibrational spectroscopy system</td>
			<td>EKSPLA</td>
			<td></td>
			<td>A commercial picosecond SFG system</td>
		</tr>
	</tbody>
</table>

interfacial molecular-level structures of polymers and biomacromolecules revealed via sum frequency generation vibrational spectroscopy

作为二阶非线性光学光谱,相和频率生成(SFG)振动光谱已广泛应用于研究各种表面和界面。这种非侵入性光学技术可以提供具有单层或亚单层灵敏度的局部分子级信息。我们在这里提供了如何选择性地检测大分子和生物大分子的埋藏界面的实验方法。并在此基础上讨论了丝纤维素的界面二级结构以及模型短链寡核苷酸双相周围的水结构。前者显示链条重叠或空间约束效应,后者显示保护功能,防止由水的性脊柱上部结构产生的Ca2+离子。

在协议部分的菲涅尔系数部分,我们已经表明,从理论上讲,一次只选择性地检测一个接口是可行的。在这里,实验,我们确认这种方法基本上是正确的,如图5和图6所示。 
图5显示了水侵入后埋藏的界面PHEMA结构,带有+150 nm PHEMA水凝胶膜,图6显示了水中表面结构与±430 nm PHEMA水凝胶膜。面板 A 和 B...

Watch this Scientific Journal Video about Interfacial Molecular-level Structures of Polymers and Biomacromolecules Revealed via Sum Frequency Generation Vibrational Spectroscopy at JoVE.com

Interfacial Molecular-level Structures of Polymers and Biomacromolecules Revealed via Sum Frequency Generation Vibrational Spectroscopy

综合利用,总频率生成(SFG)振动光谱有助于揭示聚合物和生物大分子界面发生的链构体顺序和二次结构变化。

通过相频生成振动光谱揭示聚合物和生物大分子的界面分子级结构

As a second-order nonlinear optical spectroscopy, sum frequency generation (SFG) vibrational spectroscopy has widely been used in investigating various ...

总和频率生成振动光谱用于研究具有界面选择性的接口。然而，当存在另一个接口时，菲涅尔系数方法可以帮助解决干扰效应。SFG的主要优点是面间选择性和亚层灵敏度。这种非侵入性光学技术适用于投资各种接口，如固体-液体、固实、液-液体、固气和液-气接口。我们建议初学者在光学和SFG专家的帮助下，进行大量的SFG系统操作练习。没有快捷方式。SFG尚未被公认为强大的技术，因此我们希望吸引更多的受众兴趣，并鼓励更多的研究人员应用这种技术。首先，在无水乙醇中，通过聚-2-羟基乙基甲基丙烯酸酯或PHEMA的重量溶液，准备约5毫的2%或4%。在使用前三天将解决方案留在实验室中。接下来，在分析级无水甲苯中浸泡四个红外级氟化钙右角棱镜至少12小时。然后将棱镜浸入30毫升乙醇中，用脱脂棉布擦拭表面约10分钟。用超纯水冲洗棱镜两分钟，然后用氮气干燥。接下来，将棱镜放在氧气等离子体清洁剂中，然后疏散腔室。用氧气等离子体治疗棱镜四分钟，并把它们放在室内，直到使用。薄膜制备应在血浆处理后一小时内进行。本研究根据Fresnal系数模型的计算结果，选择性地检测阻隔界面，对于选择合适的薄膜厚度具有十分重要的意义。准备准备 PHEMA 薄膜时，在旋转涂布器上将棱镜支架上固定一个干净的棱镜，并在棱镜中涂抹一滴 PHEMA 乙醇溶液。以 1，500 RPM 的速度运行旋转涂布机一分钟，准备 PHEMA 薄膜。用 PHEMA 以相同方式涂上额外的等离子处理棱镜。将薄膜在真空烤箱中加热至 80 摄氏度，至少 10 小时。为了执行实验，PHEMA 涂层的棱镜面在去ion化水中。等待 10 到 20 分钟，然后用一些频率生成光谱评估水和棱镜界面的界面PHEMA结构。操作 FGS 系统时，不要让光束直接进入您的眼睛。开始准备丝纤维素溶液加热三升0.02摩尔水化碳酸钠煮沸。煮7.5克邦比克斯莫里蚕在这个解决方案，同时搅拌30分钟。将纤维物质转移到一个干净的容器中，在两到三升去压水中搅拌8至10分钟，三次洗去不需要的丝酸分子。在60摄氏度的真空烤箱中干燥纤维物质至少15小时。接下来，将一克干、脱胶的丝纤维素溶解在四毫度9.3摩尔水化溴化锂中。在 60 摄氏度下搅拌溶液两小时。然后将丝纤维素溶液放在 3，500 道尔顿透析袋中。将溶液对一升去化水进行三天，每天更换三次。透析完成后，将丝纤维素溶液储存在四摄氏度。接下来，使用前面描述的方法清洁氟化钙棱镜，并涂上重量为 3.5% 的薄聚苯乙烯薄膜（重量聚苯乙烯溶液）。将聚苯乙烯涂层棱镜与丝纤维素溶液接触，并检查聚苯乙烯丝纤维素与SFG光谱的界面。为了开始制备寡核苷酸双面体，在0.5毫微的超纯水中溶解10纳米分子的适当单链寡核苷酸。对免费的寡核苷酸也这样做。结合解决方案，获得每毫升10纳米摩尔双工寡核苷酸溶液。然后结合两毫克的 DPPC、两毫克的脱化 DPPC 和一毫升氯仿，获得脂质溶液。接下来，清洁和血浆治疗氟化钙棱镜，如前面所述。将这个棱镜连接到朗穆尔-布洛吉特槽的样品上。用去维化的水填充槽，以每分钟一毫米的速度将棱镜的一面放入槽中。将几微升脂溶液注入水面，等待表面压力稳定在每米约12毫微吨。然后开始以每分钟五毫米的速度压缩脂质单层。当表面压力达到每米34毫纽顿时，棱镜以每分钟1毫米的速度从低谷中抬起。接下来，以1至100摩尔的比例准备500微升的双相寡核苷酸溶液和脂质溶液的混合物。然后用圆柱形聚四氟乙烯容器更换朗穆尔-布洛杰特槽，该容器内装满了去维化水。将寡核苷酸脂混合物注入水中，直到表面压力达到每米34毫微吨。将棱镜的脂质单层涂层面与脂质寡核苷酸混合物接触，形成最终样品。使用FSG光谱评估奇性水振动信号。在第一个示例中，PHEMA 水凝胶与氟化钙棱镜之间的界面显示了 SFG 光谱中明显的锐峰。这是由于氟化钙和水凝胶之间的平滑界面。水凝胶与周围水的界面具有更宽、强度较小的特点，因为水分子可以扩散到水凝胶的大部分中。在这里，当丝纤维素浓度高于临界重叠浓度时，在溶液聚苯乙烯界面上确实检测到了奇性二级结构，除非甲醇被添加为诱导剂。在临界重叠浓度以下，即使没有添加甲醇，也检测到奇性SFG信号，表明在溶液聚苯乙烯界面上形成无辅助的有序二级结构。在双面寡核苷酸锚定脂双层样品中，钙离子浓度变化对手性水信号没有显著影响，而手性水信号主要对应于小槽中手性脊柱后期的水化。相比之下，钙浓度强影响阿奇拉尔水信号，主要对应于双面链和双层周围的水层。总之，水层的手性脊椎可以保护寡核苷酸免受钙离子的污染。计算菲涅尔系数并选择适当的薄膜厚度可以解决干扰问题。如果多反射和折射被认为是正确的电场分布在接口可以调整。有其他方法可用于准备具有所需厚度的薄膜，如步进涂层和化学气相沉积。检测与粘附、摩擦、摩擦和其他特性相关的表面和面间结构可以帮助研究人员了解底层机制并开发新的功能材料。此方法也可以应用于需要调查不同接口的其他系统。但是，您希望光束传播的介质必须是透明的。

Research

JoVE Journal

Biochemistry

Fabricating a UV-Vis and Raman Spectroscopy Immunoassay Platform

制造的UV-Vis和拉曼光谱免疫平台

Immunoassays are used to detect proteins based on the presence of associated antibodies. Because of their extensive use in research and clinical settings, ...

科研

生物化学

Force Spectroscopy of Single Protein Molecules Using an Atomic Force Microscope

原子力显微镜对单蛋白质分子的力谱

The determination of the folding process of proteins from their amino acid sequence to their native 3D structure is an important problem in biology. ...

A11-positive &#946;-amyloid Oligomer Preparation and Assessment Using Dot Blotting Analysis

A11-positive ÃƒÆ’Ã…Â½Ãƒâ€šÃ‚Â²-amyloid Oligomer Preparation and Assessment Using Dot Blotting Analysis

用斑点印迹分析 A11-positive β淀粉样寡聚物的制备与评价

&#946;-amyloid (A&#946;) is a hydrophobic peptide with an intrinsic tendency to self-assemble into aggregates. Among various aggregates, A&#946; oligomer ...

Covalent Immobilization of Proteins for the Single Molecule Force Spectroscopy

单分子力谱中蛋白质共价固定化的研究

In recent years, atomic force microscopy (AFM) based single molecule force spectroscopy (SMFS) extended our understanding of molecular properties and ...

Measuring Interactions of Globular and Filamentous Proteins by Nuclear Magnetic Resonance Spectroscopy (NMR) and Microscale Thermophoresis (MST)

Measuring Interactions of Globular and Filamentous Proteins by Nuclear Magnetic Resonance Spectroscopy NMR and Microscale Thermophoresis MST

用核磁共振 (nmr) 和微尺度热能 (mst) 测量球状和丝状蛋白的相互作用

Filamentous proteins such as vimentin provide organization within cells by providing a structural scaffold with sites that bind proteins containing plakin ...

A Fluorescence Fluctuation Spectroscopy Assay of Protein-Protein Interactions at Cell-Cell Contacts

细胞细胞接触物蛋白质-蛋白质相互作用的荧光波动光谱测定

A variety of biological processes involves cell-cell interactions, typically mediated by proteins that interact at the interface between neighboring ...

Looking Outwards: Isolation of Cyanobacterial Released Carbohydrate Polymers and Proteins

向外观察:分离氰化物释放的碳水化合物聚合物和蛋白质

Cyanobacteria can actively secrete a wide range of biomolecules into the extracellular environment, such as heteropolysaccharides and proteins. The ...

Characterization at the Molecular Level using Robust Biochemical Approaches of a New Kinase Protein

使用新激酶蛋白的强生化方法在分子水平上进行表征

Extensive whole genome sequencing has identified many Open Reading Frames (ORFs) providing many potential proteins. These proteins may have important ...

OaAEP1-Mediated Enzymatic Synthesis and Immobilization of Polymerized Protein for Single-Molecule Force Spectroscopy

OaAEP1介导酶合成和聚合蛋白固定，用于单分子力光谱

Chemical and bio-conjugation techniques have been developed rapidly in recent years and allow the building of protein polymers. However, a controlled ...

Characterization of Amyloid Structures in Aging C. Elegans Using Fluorescence Lifetime Imaging

Characterization of Amyloid Structures in Aging C. Elegans Using Fluorescence Lifetime Imaging

使用荧光寿命成像在老化C.Elegans中淀粉样蛋白结构的表征

Amyloid fibrils are associated with a number of neurodegenerative diseases such as Huntington&#39;s, Parkinson&#39;s, or Alzheimer&#39;s disease. These ...