Aggregation Of Bovine Serum Albumin Research Articles

The aggregation of bovine serum albumin in solution and in the solid state.

The aggregation of bovine serum albumin (BSA) in the solid state and in solution was studied to elucidate the effect of water mobility on the aggregation rate and mechanism. The results suggest that the freeze-dried BSA forms covalently-bonded aggregates via disulphide bonding during storage in the moistened solid state and in solution. The aggregation rate largely depended on the water content. The freeze-dried BSA to which a small amount of water was added (in the moistened state) was found to be more liable to aggregation than that in solution. The aggregation rate in in the moistened solid state exhibited a maximum at a very low level of moisture. In contrast, the aggregation rate in solution increased with increasing ratio of water to protein (with decreasing protein concentration). The results suggest that the increased rate is related to the increase in water mobility, as measured by the spin-lattice relaxation time, T1, of water using 17O NMR, with increasing ratio of water to protein.

Study on protein conformation and adsorption behaviors in nanodiamond particle–proteincomplexes

In the present research, the conformation of bovine serum albumin (BSA) in thenanodiamond particle (ND)–BSA complex was studied by Fourier transform infraredspectroscopy, fluorescence spectroscopy, UV–vis spectroscopy, and circular dichroismspectroscopy. The spectroscopic study revealed that most BSA structural features could bepreserved in the complex though the BSA underwent conformational changes in thecomplex due to ND–BSA interaction. In addition, BSA adsorption isotherms andzeta-potential measurements were employed to investigate the pH dependence of theND–BSA interaction. The changes in surface charge of the ND–BSA complex with pHvariations indicated that the binding of BSA to ND might lead to not only the adsorptionof BSA onto the ND surface but also the partial breakup of ND aggregates intorelatively small ND–BSA aggregates because of the strong binding force betweenND and BSA. The results show that ND is an excellent platform for proteinimmobilization with high affinity and holds great potential to be used for biosensorapplications.

Thermal aggregation of bovine serum albumin studied by asymmetrical flow field-flow fractionation

The use of asymmetrical flow field-flow fractionation (AsFlFFF) in the study of heat-induced aggregation of proteins is demonstrated with bovine serum albumin (BSA) as a model analyte. The hydrodynamic diameter ( d h), the molar mass of heat-induced aggregates, and the radius of gyration ( R g) were calculated in order to get more detailed understanding of the conformational changes of BSA upon heating. The hydrodynamic diameter of native BSA at ambient temperature was ∼7 nm. The particle size was relatively stable up to 60 °C; above 63 °C, however, BSA underwent aggregation (growth of hydrodynamic diameter). The hydrodynamic diameters of the aggregated particles, heated to 80 °C, ranged from 15 to 149 nm depending on the BSA concentration, duration of incubation, and the ionic strength of the solvent. Heating of BSA in the presence of sodium dodecyl sulfate (1.7 or 17 mM) did not lead to aggregation. The heat-induced aggregates were characterized in terms of their molar mass and particle size together with their respective distributions with a hyphenated technique consisting of an asymmetrical field-flow fractionation device and a multi-angle light scattering detector and a UV-detector. The carrier solution comprised 8.5 mM phosphate and 150 mM sodium chloride at pH 7.4. The weight-average molar mass ( M w) of native BSA at ambient temperature is 6.6 × 10 4 g mol −1. Incubation of solutions with BSA concentrations of 1.0 and 2.5 mg mL −1 at 80 °C for 1 h resulted in aggregates with M w 1.2 × 10 6 and 1.9 × 10 6 g mol −1, respectively. The average radius of gyration and the average hydrodynamic radius of the heat-induced aggregate samples were calculated and compared to the values obtained from the size distributions measured by AsFlFFF. For comparison static light scattering measurements were carried out and the corresponding average molar mass distributions of solutions with BSA concentrations of 1.0 and 2.5 mg mL −1 at 80 °C for 1 h gave aggregates with M w 1.7 × 10 6 and 3.5 × 10 6 g mol −1, respectively.

Effect of the sugar and polyol additives on the aggregation kinetics of BSA in the presence of N-cetyl-N,N,N-trimethyl ammonium bromide

The kinetics of the aggregation of bovine serum albumin (BSA) in the presence of N-cetyl-N,N,N-trimethyl ammonium bromide (CTAB) was studied by monitoring turbidity as a function of time. BSA–CTAB aggregation exhibits an exponential growth, with a pronounced lag phase and a subsequent rapid growth of the aggregates. On the addition of sugars and polyols to BSA–CTAB solution, there is an increase in the lag time and decrease in the rate constant of growth phase indicating that the inhibitors affect both the pre- and post-nucleation processes. The concentration dependence studies of lag time of BSA–CTAB aggregation in the presence of additives points towards the involvement of more number of monomers in the nucleus/start aggregate. The increase in the stability of BSA in the presence of these additives indicates probable role of activation energy in the aggregation. However, the temperature dependence of lag time of BSA–CTAB aggregation shows that the hindrance to molecular collisions, as indicated by decrease in the pre-exponential factor, due to increased viscosity in the presence of additives is the main factor responsible for their inhibitory action. Similarly, higher viscosity of sucrose makes it a much better inhibitor of the heat and surfactant induced aggregation of BSA–CTAB than mannitol.

Protein adsorption under electrical stimulation of neural probe coated with polyaniline

Polyaniline (PANI) nanoparticles were successfully polymerized on the surface of Pt electrode to form nanostructured films. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) micrographs showed that the just-synthesized films were compact with diameter of nanoparticles on films about 50 and 30nm for HClO(4) and citric acid doped PANI films, respectively. And the surface of the electrode was coated completely with PANI films. After electrical stimulation for 1 month in 0.9% sodium chloride solution, there were no fissures appearing on PANI films. The compact film would act as a protecting membrane of the Pt surface, and is suitable to be used as the electrode coating for long-time performance. The time frame of human plasma fibronectin (FN) and bovine serum albumin (BSA) adsorption illustrated that electrical stimulation enhanced the amount of protein adsorption on PANI films up to 1.7-fold increase as compared to that without electrical stimulation. The SEM images of BSA adsorption for 120min indicated that electrical stimulation might initiate the aggregation of BSA, and the nanostructure of the PANI films could inhibit the aggregation. We also found that the protein adsorption decreased conductivity of PANI films, which maybe due to the protein barriers formed on them. These results provided a good reference for the use of conducting polymers as neural probe coating.

Gelling Properties of Microparticulated Whey Proteins

Subjecting whey proteins to high-pressure shearing with or without heating, commonly termed microparticulation, results in novel ingredients with modulated functionalities. Gelling properties of microparticulated whey proteins (MWP) were specifically assessed in this study. MWP powders were produced from commercial cheese whey retentate, standardized to 10% (w/w) protein, and subjected to microfluidization (MFZ) at 140 MPa either with or without prior heat-induced denaturation, followed by spray-drying. Gels were created from aqueous MWP dispersions either by heating at 90 degrees C for 20 min or by allowing gels to form at ambient temperature through addition of glucano-delta-lactone and/or NaCl. MWP powders produced from unheated WP dispersions created firm gels upon heating, whereas those produced from denatured WP gave only cold-set gels. Covalent and noncovalent protein-protein interactions were involved during both heat- and cold-induced gelation. Hydrophobic interactions were more pronounced during aggregation of bovine serum albumin. In conclusion, microparticulation of WP resulted in heat- and cold-set gels with different molecular and physical characteristics from those of untreated controls.

Anti-aggregation properties of trehalose on heat-induced secondary structure and conformation changes of bovine serum albumin

During our experimental work, aggregation of bovine serum albumin was obtained incubating the protein solution at 60 °C to investigate temperature-induced secondary structure, conformation changes and anti-aggregative activity of trehalose. IR-measurements suggested that in the presence of 1.0 M of trehalose there is a little increase in short segment connecting α-helical and a clearly decrease in the loss of α-helix structure and in the formation of intermolecular and antiparellel β-sheet up to 78 and 55%, respectively. Useful information also arose following the temperature evolution of Amide I′ band profile in the range of temperature between 25 and 90 °C in absence or in presence of 1.0 M trehalose. Complementary information is obtained by electrophoresis, circular dichroism, fluorescence spectroscopy, titration of SH groups and light scattering measurements. Results encouraged biotechnology and pharmaceutical application of the disaccharide and provided evidence for its utilization in degenerative diseases evolving via aggregation process.

Interaction of Guanidine-type Surfactants with Biological Substances

The interaction of guanidine-type cationic surfactants with bovine serum albumin (BSA) and liposome were investigated. Dodecylguanidine hydrochloride (C(12)A(0)G) and several dodecanoylamide alkylguanidine hydrochlorides (C(12)A(m)G, m = 2, 3, 4, 6) were used as the guanidine-type surfactants. In the interaction of these surfactants with BSA as a model protein, the binding isotherms of the surfactants to BSA were analysed. The structural change of the protein was also examined on the basis of circular dichroism and UV absobance data. In the interaction of these surfactants with liposome as a lipid bilayer model, we studied the effects of the surfactants on the solubilisation of liposomes and the release of carboxyfluorescein from liposomes. In addition, the effect of the surfactant molecular structure on the skin irritation was evaluated in connection with the interactions of the surfactants with BSA and liposome. It was found that small amounts of binding of C(12)A(0)G caused both a partial destruction of a-helix and an aggregation of BSA. C(12)A(0)G also induced the aggregation of liposomes, whereas C(12)A(m)G showed no such action. The presence of A(m) group in C(12)A(m)G appeared to reduce the skin irritation in parallel with the weakening of the interaction of the guanidine group with the protein and the lipid bilayer.

Dermatan sulfate as a stabilizer for protein stability in poly(lactide-co-glycolide) depot

Dermatan sulfate (DS), a glycosaminoglycan family, was investigated as a additive to enhance the stability of therapeutic protein with low p/ value loaded in poly(lactide-co-glycolide) (PLGA) microspheres prepared by water-in-oil-in-water (W1/O/W2) method. DS maintains negative charge below pH 3.0 because of its sulfate groups, while most anionic polymer with carboxyl groups becomes neutral charge at that pH. Thus, at pH 3.0 DS can form a polyelectrolyte complex with a protein with lower p/ such as exendin-4, insulin, and human growth hormone. In order to complex with DS, bovine serum albumin (BSA) was employed as a model protein, which has low p/value (p/= 4.8). The complex prepared at pH 3.0 showed a nano-size in the range of 100∼200 nm with a mono distribution. During the preparation of PLGA depot, DS concentration in water phase increases with decreasing the formation of non-covalent BSA aggregates and enhancing BSA loading efficiency. It means that DS/BSA complex system enabled to keep a stability of BSA at the water/organic interface. In an in vitro BSA release test, PLGA depot with DS exhibited a lower initial burst kinetic than only PLGA depot and continuous BSA release in almost 100% for 23 days. From the results, it was concluded that DS as an additive in PLGA depot, has a potential for the long-term delivery of therapeutic proteins with lower p/ value.

Influence of metal ions on thermal aggregation of bovine serum albumin: Aggregation kinetics and structural changes

Metal ions are implicated in protein aggregation processes of several neurodegenerative pathologies. In this work the effects of Cu(II) and Zn(II) ions on heat-induced structural modifications of bovine serum albumin (BSA) were studied, with the aim of delineating the role of these ions in the early stages of proteins aggregation kinetics. A joint application of different techniques was used. The aggregate growth was followed by dynamic light scattering measurements, whereas the conformational changes occurring in the protein structure were monitored by Raman and IR spectroscopy. Both in absence and in presence of metal ions, heating treatment gave rise to beta-structures to the detriment of alpha-helix conformation of BSA. The temperature of protein unfolding was not sensitively affected by the presence of Zn(II) or Cu(II) ions; on the contrary, only Zn(II) ions slightly promoted the heat-induced aggregation of the protein, since bigger aggregates were formed in their presence. The different efficacy of the Cu(II) and Zn(II) ions in promoting the BSA aggregation were highlighted by Raman measurements, assessing the role of His residues in metal binding. A distinct polypeptide folding of the two metal-BSA systems takes place, since the predominant mode of metal binding depends on metal. In particular, in Zn-BSA the metal coordination involves the imidazole N(tau) atom of His which can promote inter-molecular cross-linking.

Stability of proteins encapsulated in injectable and biodegradable poly(lactide- co-glycolide)-glucose millicylinders

Purpose To characterize protein stability in poly(lactide- co-glycolide) 50/50-glucose star (PLGA-Glu) injectable millicylinders and to compare results with linear PLGA 50/50. Methods Bovine serum albumin (BSA), a model protein, was encapsulated in PLGA-Glu and linear PLGA millicylinders by solvent-extrusion and incubated under physiological conditions. Important system properties were characterized, including: polymer molecular weight distribution, soluble acidic residues, polymer morphology, polymer water uptake, microclimate pH, protein content and release, and protein aggregation. The polymer microclimate late in the release incubation was simulated and protein recovery was analyzed by UV 280, size exclusion chromatography, amino acid analysis, and a modified Bradford assay. Results PLGA-Glu contained higher levels of low molecular weight oligomers, more rapidly biodegraded, and exhibited a lower microclimate pH than the linear 50/50 PLGA, which is the most acidic type in the PLGA family. BSA, when encapsulated in PLGA-Glu millicylinders, underwent extensive noncovalent insoluble aggregation over 2 weeks in vitro release, which was almost completely inhibited upon co-encapsulation of Mg(OH) 2. However, by 5 weeks release for base-containing formulations, although insoluble aggregation was still suppressed, the soluble fraction of protein in the polymer was unrecoverable by the modified Bradford assay. Polymer microclimate simulations with extensive protein analysis strongly suggested that the low recovery was mostly caused by base-catalyzed hydrolysis of the oligomeric fraction of BSA. Conclusions In PLGA-Glu, the acidic microclimate was similarly responsible for insoluble aggregation of encapsulated BSA. BSA aggregation was inhibited in millicylinders by co-incorporation into the polymer an insoluble base, but over a shorter release interval than linear PLGA likely because of a more acidic microclimate in the star polymer.

Role of trehalose in moisture-induced aggregation of bovine serum albumin

Moisture-induced aggregation has been identified as a key problem in the long term storage stability of therapeutic proteins. In the present work, we have investigated the impact of the disaccharide trehalose on the aggregation behavior of a model protein, bovine serum albumin (BSA) under moist conditions. About 50% aggregation of BSA was observed at a moisture level of 8 μl/10 mg protein. Including trehalose in the protein sample caused a significant reduction in aggregation. We address the probable mechanisms for the protective effect of trehalose by considering the various hypotheses that have been proposed in the literature. The techniques that have been used include denaturing and non-denaturing gel electrophoresis and tryptophan intrinsic fluorescence. The nature of the aggregates was studied by carrying out electrophoresis of the aggregated protein in the presence of reducing and chaotropic reagents. The interaction studies of aggregated BSA with Thioflavin T and CongoRed indicate the possibility of amyloid type of character in the former. These studies may explain the protective role of trehalose under conditions where the storage stability of therapeutic proteins is compromised.

The effect of glucose on bovine serum albumin denatured aggregation kinetics at high concentration

The effect of glucose (0–15 mass%) on the kinetics of bovine serum albumin (BSA) denatured aggregation at high concentration in aqueous solution has been studied by differential scanning calorimetry. The observed denatured aggregation process was irreversible and could be characterized by a denaturation temperature (T m), apparent activation energy (E a), the approximate order of reaction, and pre-exponential factor (A). As the glucose concentration increased from 0 to 15 mass%, T m increased, E a also increased from 514.59409±6.61489 to 548.48611±7.81302 kJ mol−1, and A/s−1 increased from 1.24239E79 to 5.59975E83. The stabilization increased with an increasing concentration of glucose, which was attributed to its ability to alter protein denatured aggregation kinetics. The kinetic analysis was carried out using a composite procedure involving the iso-conversional method and the master plots method. The iso-conversional method indicated that denatured aggregation of BSA in the presence and absence of glucose should conform to single reaction model. The master plots method suggested that the simple order reaction model best describe the process. This study shows the combination of iso-conversional method and the master plots method can be used to quantitatively model the denatured aggregation mechanism of the BSA in the presence and absence of glucose.

Nonisothermal kinetic analysis of the effect of protein concentration on BSA aggregation at high concentration by DSC

The effect of protein concentration on bovine serum albumin (BSA) aggregation kinetics at high concentration was studied by differential scanning calorimetry (DSC). The nonisothermal kinetic analysis of this process was carried out using a composite procedure involving the iso-conversional method and the master plots method. The observed aggregation process was characterized by denaturation temperature ( T d max ), apparent activation energy ( E), the apparent order of reaction ( n), and pre-exponential factor ( A) which all increased with the increase of BSA concentration. The results suggested that the apparent aggregation reaction of BSA approximately conformed to the simple order reaction model. The higher BSA concentration, the higher the apparent order of reaction and the more close to 2 was. The difference intrinsic fluorescence of BSA between before and after the thermal denaturation and aggregation provided the evidences of conformation changes of BSA and the substantial impact of BSA concentration on aggregation. This study showed the combination of iso-conversional method and the master plots method could be used to model the aggregation mechanism of the protein.

Multi-block poloxamer surfactants suppress aggregation of denatured proteins

On the basis of elastic light scattering, we have compared the capacity of the multi-block, surfactant copolymers Poloxamer 108 (P108), Poloxamer 188 (P188), and Tetronic 1107 (T1107), of average molecular weight 4700, 8400, and 15,000, respectively, with that of polyethylene glycol (PEG, molecular weight 8000) to suppress aggregation of heat-denatured hen egg white lysozyme (HEWL) and bovine serum albumin (BSA). We also compared the capacity of P188 to that of PEG to suppress aggregation of carboxypeptidase A denatured in the presence of trifluoroethanol and to facilitate recovery of catalytic activity. In contrast to the multi-block copolymers, PEG had no effect in inhibiting aggregation of HEWL or of carboxypeptidase A with the recovery of catalytic activity. At very high polymer:protein ratios (≥ 10:1), PEG increased aggregation of heat-denatured HEWL and BSA, consistent with its known properties to promote macromolecular crowding and crystallization of proteins. At a polymer:protein ratio of 2:1, the tetra-block copolymer T1107 was the most effective of the three surfactant copolymers, completely suppressing aggregation of heat-denatured HEWL. At a T1107:BSA ratio of 10:1, the poloxamer suppressed aggregation of heat-denatured BSA by 50% compared to that observed in the absence of the polymer. We showed that the extent of suppression of aggregation of heat-denatured proteins by multi-block surfactant copolymers is dependent on the size of the protein and the copolymer:protein molar ratio. We also concluded that at least one of the tertiary nitrogens in the ethylene-1,2-diamine structural core of the T1107 copolymer is protonated, and that this electrostatic factor underlies its capacity to suppress aggregation of denatured proteins more effectively than nonionic, multi-block poloxamers. These results indicate that amphiphilic, surfactant, multi-block copolymers are efficient as additives to suppress aggregation and to facilitate refolding of denatured proteins in solution. Because of these properties, multi-block, surfactant copolymers are suitable for application to a variety of biotechnological and biomedical problems in which refolding of denatured or misfolded proteins and suppression of aggregation are important objectives.

Thermodynamics investigation of a series of metalloporphyrazine-bovine serum albumin complexes

The equilibrium binding of the tetra-cationic complexes ( N , N ′, N ″, N ‴-tetra-methyltetra-2,3-pyridinoporphyrazinato)copper(II), ([ Cu (2,3- TMTPPA )]4+), ( N , N ′, N ″, N ‴-tetra-methyltetra-3,4-pyridinoporphyrazinato)copper(II), ([ Cu (3,4- TMTPPA )]4+), (( N , N ′, N ″, N ‴-tetra-methyltetra-3,4-pyridinoporphyrazinato)cobalt(II), ([ Co (3,4- TMTPPA )]4+) and (( N , N ′, N ″, N ‴-tetra-methyltetra-3,4-pyridinoporphyrazinato)zinc(II), ([ Zn (3,4- TMTPPA )]4+) with bovine serum albumin (BSA) has been studied in phosphate buffer pH = 7.0 and at various temperatures using multi-spectroscopy techniques. The results of resonance light scattering (RLS) studies represent no aggregate formation of porphyrazine in the surface of BSA and low tendency of these porphyrazine for aggregate formation. The binding constants and binding stoichiometries were determined by analyzing of optical absorption spectra of porphyrazine complexes at various concentration of BSA using SQUAD software. The results show that the best fitting corresponds to a 1:1 complex model between BSA and porphyrazines. The thermodynamic parameters were calculated by van't Hoff equation at various temperatures. The data indicate that the process is entropy driven suggesting that hydrophobic interactions play a considerable role in the complex formation. The binding of porphyrazine complexes to BSA quenches fluorescence emission of BSA via a dynamic mechanism and the quenching process obeys a linear Stern-Volmer relationship. The average aggregation number of BSA, which has been calculated from the analysis of fluorescence quenching data, indicates the absence of any porphyrazine induced aggregation of BSA due to its interaction with porphyrazine complexes. Fluorescence studies also indicate that porphyrazine is bound to site I of BSA placed in sub-domain IIA, where tryptophan 214 is located.

Thermal aggregation of bovine serum albumin at different pH: comparison with human serum albumin

We report here a study on thermal aggregation of BSA at two different pH values selected to be close to the isoelectric point (pI) of this protein. Our aim is to better understand the several steps and mechanisms accompanying the aggregation process. For this purpose we have performed kinetics of integrated intensity emission of intrinsic and extrinsic dyes, tryptophans and ANS respectively, kinetics of Rayleigh scattering and of turbidity. The results confirm the important role played by conformational changes in the tertiary structure, especially in the exposure of internal hydrophobic regions that promote intermolecular interactions. We also confirm that the absence of electrostatic repulsion favours the disordered non-specific interactions between molecules and consequently affects the aggregation rate. Finally, the comparison between BSA and another relative protein, HSA, allows us to clarify the role of different domains involved in the aggregation process.

Solute effects on the irreversible aggregation of serum albumin

Thermal stress on bovine serum albumin (BSA) promotes protein aggregation through the formation of intermolecular β-sheets. We have used light scattering and chromatography to study effects of (< 1 M) Na 2SO 4, NaSCN, sucrose, sorbitol and urea on the rate of the thermal aggregation. Both salts were strong inhibitors of BSA aggregation and they reduced both the size and number (concentration) of aggregate particles compared to non-ionic solutes (or pure buffer). Hence, the salts appear to suppress both nucleation- and growth rate. The non-electrolyte additives reduced the initial aggregation rate (compared to pure buffer), but did not significantly limit the extent of aggregation in samples quenched after 27 min. heat exposure (40–50% aggregation in all samples). The non-electrolytes did, however, modify the aggregation process as they consistently brought about smaller but more concentrated aggregates than pure buffer. The results are discussed along the lines of linkage- and transition state theories. In this framework, the rate of the aggregation process is governed by the equilibrium between a thermally denatured state (D) and the transition state D ≠. Thus, the effect of a solute relies on its preferential interactions with respectively D and D ≠. The current results do not show any correlation between the solutes' preferential interactions with native BSA and their effect on the rate of aggregation. This suggests that non-specific, “Hofmeister-type” interactions, which scale with the solvent accessible surface area, are of minor importance. Rather, salt induced suppression of aggregation is suggested to depend on the modulation of specific electrostatic forces in the D ≠ state.

Investigation of Adsorption Behavior of (−)-Epigallocatechin Gallate on Bovine Serum Albumin Surface Using Quartz Crystal Microbalance with Dissipation Monitoring

Quartz crystal microbalance with dissipation monitoring (QCM-D) has been employed to study the interactions between (-)-epigallocatechin gallate (EGCG) and bovine serum albumin (BSA) surface. The adsorbed mass, thickness, and viscoelastic properties of EGCG adlayer on BSA surface at various EGCG concentrations, temperatures, sodium chloride concentrations, and pH values have been determined by QCM-D in combination with the Voigt model. The adsorption isotherm of EGCG on BSA surfaces can be better described by the Freundlich model than the Langmuir model, indicating that EGCG adsorption on BSA surfaces is dominated by nonspecific hydrophobic interactions, as supported by stronger EGCG adsorption at higher temperature. Shifts in the Fourier transform infrared spectra of the BSA surface with and without EGCG adsorption disclose that hydrogen bonding might also be involved in EGCG adsorption on BSA surfaces. The addition of salt and change of pH can also influence the EGCG adsorption on BSA surfaces. Usually, higher EGCG adsorption leads to higher values of viscosity and shear elastic modulus of EGCG adlayer, which can be explained by the aggregation of BSA through EGCG bridges. Compared with EGCG, nongalloylated (+)-catechin shows much lower adsorption capacity on BSA surfaces, suggesting the importance of the galloyl group in polyphenol/protein interactions.

Sonochemical Route for Self-Assembled V2O5 Bundles with Spindle-like Morphology and Their Novel Application in Serum Albumin Sensing

Novel self-assembled V2O5 bundles with highly ordered superstructures and spindle-like morphology were synthesized by a rapid high-yielding sonochemical method. The as-prepared samples were characterized by X-ray diffraction, a field-emission scanning electron microscope, and a transmission electron microscope. The spindle-like V2O5 bundles are composed of several tens of homogeneous nanowires with diameters of 30-50 nm and lengths of 3-7 microm. A sensitive resonance light scattering method for the detection of bovine serum albumin (BSA) based on the self-assembled V2O5 bundles was developed. The results of the polarized resonance light scattering demonstrated that the Cabannes factor for the V2O5 bundles-BSA aggregates was BSA concentration-dependent.