We consider the adsorption of bovine serum albumin (BSA) on spherical polyelectrolyte brushes (SPB). The SPB consist a solid polystyrene core 100 nm diameter onto which linear chains [poly(acrylic acid), (PAA)] are grafted. BSA is studied at pH 6.1 different concentrations added salt and buffer. observe strong despite effect that particles as well dissolved charged negatively. strongest low concentration decreases drastically with increasing amounts salt. Virtually no takes place 0.1 M....

Abstract Summary: We report the synthesis of star‐shaped poly(acrylic acid) (PAA), with 5, 8, and 21 arms, by atom transfer radical polymerization tert ‐butyl acrylate. employ core‐first approach using glucose‐, saccharose‐ cyclodextrin‐based initiators. Subsequent acidic treatment poly( acrylate) (PtBA) leads to (PAA). Alkaline cleavage arms enabled us determine initiation site efficiency. The PAA stars were esterified poly(methyl (PMA). Molecular weight determination means GPC/viscosity,...

The thermodynamics and the driving forces of adsorption beta-lactoglobulin on spherical polyelectrolyte brushes (SPB) are investigated by isothermal titration calorimetry (ITC). SPB consist a polystyrene core onto which long chains poly(styrene sulfonate) grafted. Adsorption isotherms obtained from measurements ITC. analysis ITC shows clearly that process is solely driven entropy while DeltaH > 0. This finding in accordance with proposed mechanism counterion release: Patches positive charges...

Highly symmetric gold nanoparticle clusters with coordination numbers up to seven were produced by using coating block copolymers. The resulting separated density gradient centrifugation and characterized SEM optical spectroscopy (see picture). Noble metal nanoparticles exhibit excitations known as surface plasmons that produce large enhancement of the local light intensity under external illumination, particularly when are arranged in closely spaced configurations.1 interparticle gap...

We investigate the conformation of long polyelectrolyte chains attached to colloidal latex particles by cryogenic transmission electron microscopy (cryo-TEM). The dense grafting ("polyelectrolyte brush") leads a confinement counterions and concomitantly high osmotic pressure within layer core particles. Cryo-TEM has provided first model-independent direct proof for strong stretching visualization. If salt is added, cryo-TEM clearly shows how collapse because screening electrostatic...

We investigate the enzymatic activity of glucoamylase and β-glucosidase adsorbed on a novel type colloidal particles. The particles used consist poly(styrene) core onto which long chains poly(acrylic acid) or poly(styrene sulfonic are grafted ("spherical polyelectrolyte brush"). Proteins adsorb spontaneously these from aqueous solutions if ionic strength is low. Moreover, stability not impeded by proteins despite fact that up to 600 mg enzyme per gram carrier immobilized analyzed in terms...

We use small-angle x-ray scattering (SAXS) as a tool to study the binding of proteins spherical polyelectrolyte brushes (SPB) in situ. The SPB consists solid core \ensuremath{\sim} 100 nm diam onto which long chains [poly(styrene sulfonic acid, PSS) and poly(acrylic PAA)] have been densely grafted. used this investigation, Bovine Serum Albumine (BSA) Pancreatic Ribonuclease A (RNase A), adsorb strongly these if ionic strength is low despite their negative charge. Virtually no adsorption...

The adsorption of bovine serum albumin (BSA), β-lactoglobulin, and pancreatic ribonuclease A onto spherical polyelectrolyte brushes (SPB) is reported. SPB consist narrowly distributed poly(styrene) core particles (diameter ∼100 nm) which linear chains anionic polyelectrolytes are grafted. shell consists either the weak poly(acrylic acid) or strong polyacid poly(styrenesulfonate). dispersed in H2O at room temperature. secondary structure proteins was investigated by Fourier transform infrared...

The self-assembly of the biamphiphilic triblock copolymer poly(ethylene oxide)-b-poly(caprolactone)-b-poly(acrylic acid) into polymer vesicles is studied. provide both biocompatibility and biodegradability. Moreover, nature provides different surface properties in interior outer interface vesicles. Preparation aggregates by direct dissolution a solution albumin does not alter morphology aggregates, thus, they have potential to immobilize protein molecules. Since part encapsulated vesicles,...

We present a quantitative study of the catalytic activity β-d-glucosidase from almonds adsorbed on thermosensitive microgels. The core−shell particles used as carrier system consist solid polystyrene core onto which poly(N-isopropylacrylamide) (PNiPA) network is grafted. In swollen state this microgel, i.e., below critical solution temperature (LCST) PNiPA, high amounts enzyme can be immobilized into PNiPA without loss colloidal stability. enzymatic in its native form and was analyzed terms...

We have used confocal fluorescence microscopy with single molecule sensitivity to characterize uptake and release of fluorescent protein (mEosFP) molecules by individual spherical polyelectrolyte brush (SPB) nanoparticles that were immobilized on a glass surface. The SPB particles consisted solid core particle 100 nm diameter onto which long chains affixed. They could be loaded up 30 000 mEosFP in solvent low ionic strength. concentration dependence loading can described simple bimolecular...

We survey recent studies on composite particles made from spherical polyelectrolyte brushes (SPB) and catalytically active nanoparticles or enzymes. SPB consist of a solid core (diameter: ca. 100 nm) onto which long chains anionic cationic (PE) are densely grafted ("PE brush"). Immersed in water the PE layer affixed to colloidal will swell due enormous osmotic pressure confined counterions ("osmotic This confinement can be used generate metal surface SPB. Moreover, enzymes immobilized within...

We report on the translation and rotation of particle clusters made through combination spherical building blocks. These present ideal model systems to study motion objects with complex shape. Since they could be separated into fractions well-defined configurations a sufficient scale because their overall dimensions were below 300 nm, translational rotational diffusion coefficients doublets, triplets, tetrahedrons determined by polarized dynamic light scattering (DLS) depolarized (DDLS). The...

Recent experiments showed significant adsorption of bovine serum albumin (BSA) in spherical polyelectrolyte brushes (SPB) consisting polyacrylic acid, even for pH values above the isoelectric point protein, when both protein and polyion are negatively charged. To describe these experimental findings theoretically, we have constructed a box model an annealed brush weak that includes BSA. At equilibrium chemical potential BSA solution equals at each location brush, while net force on polyions...

The adsorption of bovine hemoglobin (BHb) onto colloidal spherical polyelectrolyte brushes (SPBs) is studied by a combination small-angle X-ray scattering (SAXS) and Fourier transform infrared spectroscopy (FTIR). SPBs consist polystyrene core which long chains poly(styrene sulfonic acid) are grafted. Hemoglobin tetrameric protein that disassembles at low pH's high ionic strengths. embedded into the brush layer composed strong polyacids. Thus, subjected to pH strength largely differs from...

We present the first time-resolved investigation of motions proteins in densely grafted layers spherical polyelectrolyte brushes. Using small-angle x-ray scattering combined with rapid stopped-flow mixing, we followed uptake bovine serum albumin by poly(acrylic acid) layer high spatial and temporal resolution. find that total amount adsorbed protein scales time as ${t}^{1/4}$. This subdiffusive behavior is explained on basis directed motion along chains.

We used two-photon excitation fluorescence correlation spectroscopy (FCS) and neutron reflectometry to study in situ the effect of salt concentration on degree protein binding polyelectrolyte brushes. The bovine serum albumin (BSA) poly(acrylic acid) (PAA) brushes was characterized at neutral pH values where both carry a negative charge. Spherical PAA brush particles were FCS experiments, whereas planar served as substrate experiments. It has been found that BSA binds strongly spherical...

The structure of colloidal latex particles in dilute suspension at room temperature is investigated by cryogenic transmission electron microscopy (cryo-TEM). Two types are analyzed: (i) core made polystyrene with a thin layer poly(N-isopropylacrylamide) (PNIPAM) and (ii) core-shell consisting onto which network cross-linked PNIPAM affixed. Both systems also studied small-angle X-ray scattering (SAXS). radial density profile both have been derived from the cryo-TEM micrographs image...

We created hierarchically ordered structures of nanoparticles on smooth planar hydrophilic substrates by drying colloidal dispersions in confinement under macroscopic stamps with microscopically wrinkled surfaces. Experiments were carried out model nanoparticle suspensions that possess high stability and monodispersity. The ranged from single parallel lines particles to arrays dense prismatic ridges. type observed structure could be controlled the particle concentration initial dispersion....

We used two-photon excitation fluorescence fluctuation spectroscopy with photon counting histogram (PCH) analysis as a new tool to study the binding of globular proteins colloidal particles in situ. Whereas fluctuations are traditionally evaluated by calculating autocorrelation function (fluorescence correlation spectroscopy), complementary PCH has been performed this which is advantageous when particle concentrations multicomponent system interest and can be distinguished through brightness...

Abstract Summary: Monodisperse thermosensitive PS‐NIPA core‐shell particles composed of a PS core and cross‐linked PNIPA shell can be successfully synthesized by novel method: photoemulsion polymerization. Cryo‐TEM images indicate clearly the morphology particles: A homogeneous regular has been affixed on spherical core. DLS measurements that obtained latex are thermosensitive. The networks with different cross‐linking densities shrink re‐swell temperature volume transition is around 32 °C...

The fabrication of small assemblies spherical colloidal particles is presented. Basic principles the preparation miniemulsions were combined with concept originally described by Pine and co-workers for clusters from microspheres. application ultrasonic emulsification limits size distribution emulsion droplets thus statistical number per droplet. droplet sizes together use building blocks in submicrometer range leads to large yields well-defined diameters below 300 nm. Such might serve build...