Silica nanoparticles for the layer-by-layer assembly of fully electro-active cytochrome c multilayers
نویسندگان
چکیده
BACKGROUND For bioanalytical systems sensitivity and biomolecule activity are critical issues. The immobilization of proteins into multilayer systems by the layer-by-layer deposition has become one of the favorite methods with this respect. Moreover, the combination of nanoparticles with biomolecules on electrodes is a matter of particular interest since several examples with high activities and direct electron transfer have been found. Our study describes the investigation on silica nanoparticles and the redox protein cytochrome c for the construction of electro-active multilayer architectures, and the electron transfer within such systems. The novelty of this work is the construction of such artificial architectures with a non-conducting building block. Furthermore a detailed study of the size influence of silica nanoparticles is performed with regard to formation and electrochemical behavior of these systems. RESULTS We report on interprotein electron transfer (IET) reaction cascades of cytochrome c (cyt c) immobilized by the use of modified silica nanoparticles (SiNPs) to act as an artificial matrix. The layer-by-layer deposition technique has been used for the formation of silica particles/cytochrome c multilayer assemblies on electrodes. The silica particles are characterized by dynamic light scattering (DLS), Fourier transformed infrared spectroscopy (FT-IR), Zeta-potential and transmission electron microscopy (TEM). The modified particles have been studied with respect to act as an artificial network for cytochrome c and to allow efficient interprotein electron transfer reactions. We demonstrate that it is possible to form electro-active assemblies with these non-conducting particles. The electrochemical response is increasing linearly with the number of layers deposited, reaching a cyt c surface concentration of about 80 pmol/cm2 with a 5 layer architecture. The interprotein electron transfer through the layer system and the influence of particle size are discussed. CONCLUSIONS This study demonstrates the ability to construct fully electro-active cyt c multilayer assemblies by using carboxy-modified silica nanoparticles. Thus it can be shown that functional, artificial systems can be build up following natural examples of protein arrangements. The absence of any conductive properties in the second building block clearly demonstrates that mechanisms for electron transfer through such protein multilayer assemblies is based on interprotein electron exchange, rather than on wiring of the protein to the electrode.The construction strategy of this multilayer system provides a new controllable route to immobilize proteins in multiple layers featuring direct electrochemistry without mediating shuttle molecules and controlling the electro-active amount by the number of deposition steps.
منابع مشابه
Self assembly and optical properties of dendrimer nanocomposite multilayers.
Ultrathin multilayers are important for electrical and optical devices, as well as for immunoassays, artificial organs, and for controlling surface properties. The construction of ultrathin multilayer films by electrostatic layer-by-layer deposition proved to be a popular and successful method to create films with a range of electrical, optical, and biological properties. Dendrimer nanocomposit...
متن کاملInvestigation on magnetic and microwave behavior of magnetite nanoparticles coated carbon fibers composite
Radar absorbing materials, i.e. magnetite (Fe3O4) coated carbon fibers (MCCFs) were fabricated by electro-deposition technique. Black-colored single spinel phase Fe3O4 nanoparticles was easily synthesized by hydrothermal method using reduction of a Fe (III) - Triethanolamine complex in an aqueous alkaline solution at 60-80 ◦C. Uniform and compact Fe3O4 films were fabricated on nitric acid treat...
متن کاملPreparation of Novel Thin-Film Composite Nanofiltration Membranes for Separation of Amoxicillin
Several novel composite membranes were prepared to separate and recycle amoxicillin from pharmaceutical wastewater via nanofiltration process. The synthesis of these membranes included three stages: 1- preparation of polysulfone ultrafiltration membranes as a support via phase separation process, 2- modification of its surface by interfacial polymerization as a selective layer (polyamide), and ...
متن کاملFacile Synthesis of Catalytic AuPd Nanoparticles within Capillary Microreactors Using Polyelectrolyte Multilayers for the Direct Synthesis of H2O2
Microreactors present innovative solutions for problems pertaining to conventional reactors and therefore have seen successful application in several industrial processes. Yet, its application in heterogeneously catalyzed gas-liquid reactions has been challenging, mainly due to the lack of an easy and flexible methodology for catalyst incorporation inside these reactors. Herein, we report a fac...
متن کاملSecond Harmonic Generation Diagnostic of Layer by Layer Deposition from Disperse Red 1–Functionalized Maleic Anhydride Copolymer
Layer-by-layer (LBL) electrostatic assembly of poly-electrolytes is proving to be an increasingly rich and versatile technique for the formation of multilayered thin films with a wide range of electrical, magnetic, and optical properties. In the present work we synthesized a new nonlinear optical (NLO) maleic acid copolymer containing Disperse Red 1 moieties, built-up multilayer assemblies by a...
متن کامل