聚合物层状组装膜

介绍了近几年来我们研究组在层状组装膜的构筑以及功能化研究方面取得的一些最新进展.包括结合表面溶胶-凝胶技术与静电层状组装技术,实现了二阶非线性基团在层状组装多层膜中的非对称排列,制备了具有二阶非线性效应的膜材料;采用室温压印技术,发展了一种简便、经济和具有普适性的层状组装聚合物膜图案化方法;以轻度交联的聚合物微凝胶为构筑基元,制备了具有高负载量的聚合物层状组装膜;发展了一种基于离子剥离技术的层状组装自支持膜制备方法;基于层状组装技术,制备了具有超疏水和抗反射功能的涂层.     

Effect of the layer-by-layer (LbL) deposition method on the surface morphology and wetting behavior of hydrophobically modified PEO and PAA LbL films

We demonstrate that the surface morphology and surface-wetting behavior of layer-by-layer (LbL) films can be controlled using different deposition methods. Multilayer films based upon hydrogen-bonding interactions between hydrophobically modified poly(ethylene oxide) (HM-PEO) and poly(acrylic acid) (PAA) have been prepared using the dip- and spin-assisted LbL methods. A three-dimensional surface structure in the dip-assisted multilayer films appeared above a critical number of layer pairs owing to the formation of micelles of HM-PEO in its aqueous dipping solution. In the case of spin-assisted HM-PEO/PAA multilayer films, no such surface morphology development was observed, regardless of the layer pair number, owing to the limited rearrangement and aggregation of HM-PEO micelles during spin deposition. The contrasting surface morphologies of the dip- and spin-assisted LbL films have a remarkable effect on the wetting behavior of water droplets. The water contact angle of the dip-assisted HM-PEO/PAA LbL films reaches a maximum at an intermediate layer pair number, coinciding with the critical number of layer pairs for surface morphology development, and then decreases rapidly as the surface structure is evolved and amplified. In contrast, spin-assisted HM-PEO/PAA LbL films yield a nearly constant water contact angle due to the surface chemical composition and roughness that is uniform independent of layer pair number. We also demonstrate that the multilayer samples prepared using both the dip- and spin-assisted LbL methods were easily peeled away from any type of substrate to yield free-standing films; spin-assisted LbL films appeared transparent, while dip-assisted LbL films were translucent.     

Spontaneous catalytic generation of nitric oxide from S-nitrosothiols at the surface of polymer films doped with lipophilic copperII complex

A new approach for preparing potentially more blood-compatible nitric oxide (NO)-generating polymeric materials is described. The method involves creating polymeric films that have catalytic sites within (lipophilic copper(II) complex) that are capable of converting endogenous S-nitrosothiols present in blood (S-nitrosoglutathione (GSNO), S-nitrosocysteine (CysNO), etc.) to NO. The catalytic NO generation reaction involves the initial reduction of Cu(II) to Cu(I) within the complex by appropriate reducing agents (e.g., thiolates or ascorbate), followed by the reduction of S-nitrosothiols to NO by the Cu(I) complex at the polymer/solution interface. The NO fluxes observed when PVC or polyurethane films containing the copper(II) complex are placed in solutions containing physiological levels of nitrosothiols (muM levels) reach ca. 8 x 10-10 mol cm-2 min-1, greater than that produced by normal endothelial cells that line all healthy blood vessels. It is thus anticipated that this spontaneous catalytic generation of NO from endogenous nitrosothiols will render such polymeric materials more thromboresistant when in contact with blood in vivo.     

A high activity photocatalyst of hierarchical 3D flowerlike ZnO microspheres: synthesis, characterization and catalytic activity

This contribution reports the design, preparation, and characterization of nanostructured hybrid films of silver nanoparticles (AgNPs) and a tailored nitric oxide (NO) photodonor. They were achieved by exploiting effective interfacial interactions between an amino-terminated NO photodonor spread onto water surface and naked AgNPs dissolved in the water subphase. The morphology, the spectroscopic features, and the interaction between the two components in the floating films at the air/water interface were inspected by Brewster Angle Microscopy, UV-Vis reflection, and polarization-modulation infrared reflection-absorption spectroscopy. AgNPs and the NO photodonor were successfully transferred onto hydrophobized quartz substrates by horizontal lifting deposition and the resulting multilayer films were characterized by UV-Vis absorption spectroscopy and transmission electron microscopy, respectively. The results obtained showed the presence of both isolated AgNPs and assemblies of AgNPs having nanodimensional character in the films. The photochemical properties of the NO photodonor were well preserved in the hybrid multilayers. In fact, they were able to release NO under visible light excitation, as unambiguously demonstrated by the direct and in real-time monitoring of this transient species using an ultrasensitive electrode, and the transfer of the released NO to a protein such as myoglobin.     

层-层自组装构建固相可降解基因传递体系的研究

近年来,随着人类对基因研究的深入,基因治疗作为一种新的手段,受到人们的广泛重视．在组织工程材料、介入医用材料和医用植入体的应用中,与传统的溶液给药方式不同,基因技术需要一种可直接作用于材料表面贴壁细胞的长效、高转染固相基因传递体系．目前,国内外研究者将蛋白质药     

Self-assembled graphene/azo polyelectrolyte multilayer film and its application in electrochemical energy storage device

Graphene/azo polyelectrolyte multilayer films were fabricated through electrostatic layer-by-layer (LbL) self-assembly, and their performance as electrochemical capacitor electrode was investigated. Cationic azo polyelectrolyte (QP4VP-co-PCN) was synthesized through radical polymerization, postpolymerization azo coupling reaction, and quaternization. Negatively charged graphene nanosheets were prepared by a chemically modified method. The LbL films were obtained by alternately dipping a piece of the pretreated substrates in the QP4VP-co-PCN and nanosheet solutions. The processes were repeated until the films with required numbers of bilayers were obtained. The self-assembly and multilayer surface morphology were characterized by UV-vis spectroscopy, AFM, SEM, and TEM. The performance of the LbL films as electrochemical capacitor electrode was estimated using cyclic voltammetry. Results show that the graphene nanosheets are densely packed in the multilayers and form random graphene network. The azo polyelectrolyte cohesively interacts with the nanosheets in the multilayer structure, which prevents agglomeration of graphene nanosheets. The sheet resistance of the LbL films decreases with the increase of the layer numbers and reaches the stationary value of 1.0 × 10(6) Ω/square for the film with 15 bilayers. At a scanning rate of 50 mV/s, the LbL film with 9 bilayers shows a gravimetric specific capacitance of 49 F/g in 1.0 M Na(2)SO(4) solution. The LbL films developed in this work could be a promising type of the electrode materials for electric energy storage devices.     

Nanostructured micellar films formed via layer-by-layer deposition of photoactive polymer

Photoactive nanostructured micellar films were prepared from the amphiphilic copolymer poly(sodium styrenesulfonate- stat-2-vinylnaphthalene) (PSSS- stat-VN) and cationic polyelectrolyte poly(diallyldimethylammonium chloride) (PDADMAC) or poly(allylamine hydrochloride) (PAH) on quartz and silicon substrates via layer-by-layer (LbL) electrostatic self-assembly. The macromolecules of this amphiphilic copolymer adopt a coiled micellar conformation in aqueous solution that is preserved in the films as evidenced by atomic force microscopy (AFM) and spectroscopic studies. The hydrophobic domains present in the film can serve as host sites for various organic molecules. The probe molecules reside in those isolated nanosize domains. Their aggregation and quenching of their emission is eliminated. The experiments showed a regular growth of multilayer thickness and the content of solubilized compounds in the films. Thus, a defined amount of the hydrophobic compounds of interest may be introduced into these water-processable polymeric films. Some stratification of the films was induced by the presence of stiff nanoparticle-like micelles. That makes these films an important new material for studies of photoinduced energy and electron transfer.     

Fabrication of titanium dioxide and tungstophosphate nanocomposite films and their photocatalytic degradation for methyl orange

Photocatalytic multilayer films with different numbers of bilayers were prepared via an electrostatic layer-by-layer (LbL) self-assembly method. These LbL films were characterized by UV-vis spectroscopy, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). Our results indicate that TiO(2) and tungstophosphate (H(3)PW(12)O(40), abbreviated as PW(12)) are successfully incorporated into the thin films. The as-prepared (TiO(2)/PW(12))(n) films show good photocatalytic performance toward methyl orange (MO) solution at pH 2.0, which is attributed to the synergistic effect between TiO(2) and PW(12). The effect of experimental parameters including number of bilayers, initial concentration, and pH value of dye solution were also studied. The multilayer films can be easily recovered and reused several times with little change of degradation, indicating that they are stable under the ultraviolet (UV) irradiation. The detection of active species displays that active holes (h(+)) play a dominant role for MO photodegradation in the TiO(2)/PW(12) system. Taking advantage of immobilization of catalysts on glass slides, the problem of recovery is solved. It is expected that photocatalytic multilayer films have substantial applications in industry.     

陶瓷泡沫空气过滤器涂覆中孔TiO2薄膜用于室内空气净化中高效光催化降解NO

由于人们80%的时间呆在室内,室内空气的质量直接影响人类健康,因此近年来室内空气质量越来越受到人们的关注.室内污染物包括CO氮氧化物(NOx)和挥发性有机化合物(VOCs),它们给人体健康带来众多负面影响.更为重要的是,考虑到节能,现代建筑的空气密闭性大都较高,但这种减少吸入新鲜空气的设计直接导致室内各种污染物的累积.有些家用电器,如燃气灶和热水器,在使用的时候会涉及到煤、油和天然气的燃烧,特别是通风较差的情况下会成为室内主要的污染源.常规的治理技术,包括吸附和过滤,其成本相对较高,也不适用于低浓度污染物的治理.尤其是更换不及时的过滤器在排风系统中可能会成为VOCs的一个来源.因此,很有必要开发一种新型的技术以降低室内污染物的浓度和保持一个清洁的室内空气环境,从而保障人们的身体健康.光催化是去除室内空气污染物的有效方法.例如, TiO2、钛酸铋和钛酸锶等具有强氧化能力和稳定的光催化活性,因而是高效的光催化剂.一般而言,通常报道的TiO2光催化剂是高度分散的、或悬浮于液体介质中的细小颗粒或粉末.然而,粉末状的TiO2光催化剂不适宜于室内空气净化,因为它变得可吸入而对人体健康造成不利的影响.因此,人们尝试将TiO2颗粒作为薄膜固定在不同的刚性载体上,如玻璃、不锈钢和铝合金板.对基体进行涂覆可显著影响光催化时反应物的表面吸附行为.一般而言,光催化薄膜通常涂覆在平面上,如蜂窝空气过滤器.三维(3D)多孔的陶瓷泡沫对气体通过具有非常好的流体性质,因此本文以它作为涂覆的基体.这种陶瓷泡沫具有3D多孔结构,多种孔密度、比表面积和化学性质.3D多孔陶瓷泡沫空气过滤器的床层空隙率较高,因此使用时压降较低,且不像蜂窝空气过滤器,它具有复杂多变的孔结构,可增强流体的扰动和混合.另外,3D多孔陶瓷泡沫空气过滤器的开发多孔和网状的结构使得在催化体系具有非常好的气体动力学性质,催化剂表面和气体反应物有充分的接触.多孔材料在液相或气相催化反应中具有独特的优势,因此,陶瓷泡沫、多孔的氧化铝、多孔硅胶.分子筛和活性炭经常被用作催化剂载体.在固体基体上TiO2膜的形成可能使得TiO2光催化剂的有效比表面积降低,从而导致其光催化活性下降.然而,由于具有中孔结构的TiO2薄膜的比表面积大,其用于催化反应的活性位也更多,因此使用时仍然具有较高的活性.前期研究表明,涂覆在平面玻璃、不锈钢和氧化铝基体上的中孔TiO2薄膜用于环境净化时表现出增强的光催化效率.另外,室内环境中NO和NO2的浓度一般分别为几百个ppb之内和100 ppb以下.可见, NO是主要的室内空气污染物,对人体健康危害较大.基于此,本文首次采用反胶束法将中孔锐钛矿TiO2薄膜均匀一地涂覆在3D多孔高比表面积的泡沫过滤器上,采用X射线衍射、扫描电镜、X射线光电子能谱、N2吸附-脱附、紫外-可见光光谱和原子力显微镜对所制样品进行了表征,并将样品用于紫外光下催化降解NO,以揭示所制的中孔TiO2涂层具有高的比表面积和高的光催化活性,从而克服使用TiO2粉末所带来的不足.结果表明,由于中孔TiO2薄膜涂层具有较大的有效比表面积,其表面存在很多吸附活性位,用于吸附在反应过程中形成的水蒸汽、气相反应物和产物,因而具有更高的光催化活性,因此在陶瓷泡沫空气净化系统中可以高效地光催化NO降解：在所考察的不同孔密度的陶瓷泡沫过滤器涂覆的TiO2上400 ppb的NO单程转化率均在92.5%以上,高于涂覆在平面陶瓷砖上的TiO2.该陶瓷过滤器的3D多孔特性可增强流体的扰动和混合,使得气相反应物与光催化剂表面有着充分的接触;其大的孔密度也导致高的光催化速率.另外,本文所制样品在所有反应过程中均保持较高且稳定的NO降解速率,这表明其在NO降解反应中没有失活.     

羧甲基香菇多糖表面修饰的聚乳酸材料的表面性能研究

制备了香菇多糖羧甲基衍生物,再通过化学接枝方法利用共价键将羧甲基香菇多糖固定在氨基化聚乳酸基材表面,得到羧甲基香菇多糖化学接枝修饰的聚乳酸材料.此外,通过在氨基化聚乳酸基材表面进行羧甲基香菇多糖与壳聚糖的层层自组装,得到生物多糖层层自组装修饰的聚乳酸材料.采用扫描电子显微镜、水接触角测量仪、抗菌活性测试、溶血试验和血栓试验等方法对被修饰聚乳酸材料的表面性能和生物性能进行了分析和比较.结果表明采用2种表面修饰方法得到的羧甲基香菇多糖修饰的聚乳酸材料的亲水性、血液相容性以及对大肠杆菌抗菌活性得到改善.与化学接枝方法相比,经过羧甲基香菇多糖与壳聚糖层层自组装修饰的聚乳酸材料具有更好的亲水性、血液相容性和抗菌活性.     

Layer-by-layer-assembled multilayer films of polyelectrolyte-stabilized surfactant micelles for the incorporation of noncharged organic dyes

Noncharged pyrene molecules were incorporated into multilayer films by first loading pyrene into poly(acrylic acid) (PAA)-stabilized cetyltrimethylammonium bromide (CTAB) micelles (noted as PAA&(Py@CTAB)) and then layer-by-layer (LbL) assembled with poly(diallyldimethylammonium chloride) (PDDA). The stable incorporation of pyrene into multilayer films was confirmed by quartz crystal microbalance (QCM) measurements and UV-vis absorption spectroscopy. The resultant PAA&(Py@CTAB)/PDDA multilayer films show an exponential growth behavior because of the increased surface roughness with increasing number of film deposition cycles. The present study will open a general and cost-effective avenue for the incorporation of noncharged species, such as organic molecules, nanoparticles, and so forth, into LbL-assembled multilayer films by using polyelectrolyte-stabilized surfactant micelles as carriers.     

Renewable nanocomposite layer-by-layer assembled catalytic interfaces for biosensing applications

A novel, easily renewable nanocomposite interface based on layer-by-layer (LbL) assembled cationic/anionic layers of carbon nanotubes customized with biopolymers is reported. A simple approach is proposed to fabricate a nanoscale structure composed of alternating layers of oxidized multiwalled carbon nanotubes upon which is immobilized either the cationic enzyme organophosphorus hydrolase (OPH; MWNT-OPH) or the anionic DNA (MWNT-DNA). The presence of carbon nanotubes with large surface area, high aspect ratio and excellent conductivity provides reliable immobilization of enzyme at the interface and promotes better electron transfer rates. The oxidized MWNTs were characterized by thermogravimetric analysis and Raman spectroscopy. Fourier transform infrared spectroscopy showed the surface functionalization of the MWNTs and successful immobilization of OPH on the MWNTs. Scanning electron microscopy images revealed that MWNTs were shortened during sonication and that LbL of the MWNT/biopolymer conjugates resulted in a continuous surface with a layered structure. The catalytic activity of the biopolymer layers was characterized using absorption spectroscopy and electrochemical analysis. Experimental results show that this approach yields an easily fabricated catalytic multilayer with well-defined structures and properties for biosensing applications whose interface can be reactivated via a simple procedure. In addition, this approach results in a biosensor with excellent sensitivity, a reliable calibration profile, and stable electrochemical response.     

Fabrication of free-standing multilayer films by using pH-responsive microgels as sacrificial layers

A facile way to prepare free-standing polyelectrolyte multilayer films of poly(sodium 4-styrenesulfonate)(PSS)/poly(diallyldimethylammonium)(PDDA) was developed by applying a new pH-dependent sacrificial system based on cross-linked poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) microgels. The tertiary amine groups of PDMAEMA microgels can be protonated in acidic environment, and the protonated microgels were deposited by layer-by-layer (LbL) technique with PSS. PSS/PDDA multilayer films were constructed on the top of the PSS/microgels sacrificial layers. The LbL assembly process was investigated by UV–vis spectroscopy. Further study shows that the free-standing PSS/PDDA multilayer films can be obtained within 3 min by treating the as-prepared films in alkali aqueous solution with a pH of 12.0. The pH-triggered exfoliation of PSS/PDDA multilayer films provides a simple and facile way to prepare LbL assembled free-standing multilayer films.     

Fabrication and Catalytic Properties of Films Based on Metal Ion-ligand Interaction between K_2PdCl_4 and 3-Amino-3-(4-pyridinyl)-propionitrile

This work presents a highly active and reusable heterogeneous film catalytic assembly for hydrogenation reduction of aromatic nitro compounds. The multilayer structures of PEI-(K2PdCl4-P1)n-film(PEI = polyethylenmine, P1 = 3-amino-3-(4-pyridinyl)-propionitrile) bound to quartz slides were fabricated by layer-by-layer(LbL) self-assembly method. Various characterization techniques including X-ray photoelectron spectroscopy(XPS), inductively coupled plasma OES spectrometer(ICP), UV-vis spectroscopy and atomic force microscopy(AFM) were employed to reveal the growth process of the resulting LbL multilayers in detail. Subsequent in situ reduction by H2 produced Pd nanoparticles embedded in such films were used as catalyst for the hydrogenation of nitroarenes. The catalytic performance test shows that the thin film catalyst can be applied to the hydrogenation reaction of various substituted nitroaromatics, and exhibits good catalytic activity and good catalyst stability. It is worth mentioning that our catalytic films can be easily removed from the reaction system in any time during the reaction, and the catalytic activity could be fully recovered when reused directly in another catalytic cycle for five times.     

Rapid and reversible switching between superoleophobicity and superoleophilicity in response to counterion exchange

We use a simple layer-by-layer (LbL) assembly and counterion exchange technology to rapidly and reversibly manipulate the oleophobicity of the textured aluminum surfaces. Such textured surfaces can be produced by the HCl etching and boiling water treatment of the flat aluminum plates. The LbL deposition of polyelectrolytes is performed on these surfaces to generate the polyelectrolyte multilayer films. The films are able to coordinate with perfluorooctanoate anions, leading to the surfaces with different oleophobicity. The resulting surface produced by 1.5 cycles of polyelectrolyte deposition exhibits superoleophobicity by displaying contact angles greater than 150° with low surface tension liquids. Counterion exchange in this polyelectrolyte multilayer emerged easily to control the surface composition, which leads to tunable wettability that can be rapidly and reversibly switched between superoleophobicity and superoleophilicity.     

Electropolymerization of layer‐by‐layer precursor polymer films

The layer‐by‐layer (LbL) self‐assembly has been used to fabricate polymer thin films on any solid substrates. The multilayer polymer thin films are constructed by alternating adsorption of anionic and cationic polymers. Polyelectrolyte multilayer ultrathin films containing anionic poly[2‐(thiophen‐3‐yl)ethyl methacrylate‐co‐methacrylic acid]; P(TEM‐co‐MA) and cationic poly[4‐(9H‐carbazol‐9‐yl)‐N‐butyl‐4‐vinyl pyridium bromide]; P4VPCBZ, were fabricated. The growth of multilayer ultrathin films was followed by UV–Vis absorption spectrophotometer and surface plasmon resonance spectroscopy (SPR). The deposition of P(TEM‐co‐MA)/P4VPCBZ as multilayer self‐assembled ultrathin films regularly grow which showed linear growth of absorbance and thickness with increasing the number of layer pair. Cross‐linking of the layers was verified by cyclic voltammetry (CV), UV–Vis spectrophotometry and electrochemical surface plasmon resonance (EC‐SPR) spectroscopy with good electro‐copolymerizability. This was verified by spectroelectrochemistry. The SPR angular‐reflectivity measurement resulted in shifts to a higher reflectivity according to the change in the dielectric constant of the electropolymerized film. Copyright © 2011 John Wiley & Sons, Ltd.     

Synthesis, characterization, and immobilization of Prussian blue-modified Au nanoparticles: application to electrocatalytic reduction of H2O2

Au nanoparticles modified with electroactive Prussian blue (PB) were for the first time synthesized by a simple chemical method. Transmission electronic microscopy showed that the average size of the Prussian blue shell/Au core hybrid composite (PB@Au) was about 50 nm, and Fourier transform IR, UV-vis spectra, and cyclic voltammetry confirmed the existence of PB on the surface of Au nanoparticles. Using the LbL technique, multilayer thin films of PB@Au nanoparticles were prepared by the alternate adsorption of oppositely charged linear polyelectrolyte poly(allylamine hydrochloride) (PAH) onto ITO glass for the construction of a hydrogen peroxide sensor. The novel multilayer films were characterized by SEM, cyclic voltammetry, and UV-visible absorption spectroscopy. The {PAH/PB@Au}n multilayer-modified electrode showed a well-defined pair of redox peaks and dramatic catalytic activity toward the reduction of hydrogen peroxide.     

Enhanced charge transport and incorporation of redox mediators in layer-by-layer films containing PAMAM-encapsulated gold nanoparticles

In this work, we exploit the molecular engineering capability of the layer-by-layer (LbL) method to immobilize layers of gold nanoparticles on indium tin oxide (ITO) substrates, which exhibit enhanced charge transfer and may incorporate mediating redox substances. Polyamidoamine (PAMAM generation 4) dendrimers were used as template/stabilizers for Au nanoparticle growth, with PAMAM-Au nanoparticles serving as cationic polyelectrolytes to produce LbL films with poly(vinylsulfonic acid) (PVS). The cyclic voltammetry (CV) of ITO-PVS/PAMAM-Au electrodes in sulfuric acid presented a redox pair attributed to Au surface oxide formation. The maximum kinetics adsorption is first-order, 95% of the current being achieved after only 5 min of adsorption. Electron hopping can be considered as the charge transport mechanism between the PVS/PAMAM-Au layers within the LbL films. This charge transport was faster than that for nonmodified electrodes, shown by employing hexacyanoferrate(III) as the surface reaction marker. Because the enhanced charge transport may be exploited in biosensors requiring redox mediators, we demonstrate the formation of Prussian blue (PB) around the Au nanoparticles as a proof of principle. PAMAM-Au@PB could be easily prepared by electrodeposition, following the ITO-PVS/ PAMAM-Au LbL film preparation procedure. Furthermore, the coverage of Au nanoparticles by PB may be controlled by monitoring the oxidation current.     

Synthesis, characterization and immobilization of Prussian blue nanoparticles. A potential tool for biosensing devices

Prussian blue (PB) particles with the size of ca. 5 nm were synthesized and immobilized in a multilayer structure, as a strategy for the potential development of an amperometric transducer for oxidase-enzyme-based biosensors. Multilayer films composed of PB and poly(allylamine hydrochloride) (PAH) were prepared via layer-by-layer (LbL) sequential deposition. The process was carefully monitored by UV-vis spectroscopy and cyclic voltammetry. The increase of the redox current peaks during the layer-by-layer deposition demonstrated that charge propagation within the film occurs. Linear increase of UV-vis absorbance with the number of deposited bilayers indicates that well-organized systems have been elaborated. ITO electrodes coated with PB/PAH films were used successfully for detecting H2O2, sensitivity being dependent on the number of PB/PAH layers.     

Alternate assemblies of platinum nanoparticles and metalloporphyrins as tunable electrocatalysts for dioxygen reduction

Through electrostatic layer-by-layer (LBL) assembly, negatively charged citrate-stabilized platinum nanoparticles (PtNPs) and positively charged [tetrakis(N-methylpyridyl)porphyrinato] cobalt were alternately deposited on a 4-aminobenzoic acid-modified glassy carbon electrode and also on indium tin oxide substrates, directly forming the three-dimensional nanostructured materials. Thus-prepared multilayer films were characterized by UV--visible spectroscopy, surface plasmon resonance (SPR) spectroscopy, atomic force microscopy (AFM), and cyclic voltammetry. Regular growth of the multilayer films is monitored by UV--visible spectroscopy and SPR spectroscopy. AFM provides the morphology of the multilayer films. The PtNPs containing multilayer films exhibit high electrocatalytic activity for the reduction of dioxygen with high stability. Rotating disk electrode voltammetry and rotating ring-disk electrode voltammetry demonstrate that the PtNP-containing multilayer films can catalyze an almost four-electron reduction of O(2) to H(2)O in an air-saturated 0.5 M H(2)SO(4) solution. Furthermore, the electrocatalytic activity of the films could be further tailored by simply choosing different cycles in the LBL process or more specifically the amount of the assembly components in the films. The high electrocatalytic activity and good stability for dioxygen reduction make the PtNP-containing multilayer films potential candidates for the efficient cathode material in fuel cells.