酶法合成的葡萄糖氧化酶-纳米金复合物的直接电化学与生物传感

将NaAuCl₄、葡萄糖氧化酶（GOx）和葡萄糖混合,借一步酶促反应制得吸附GOx的金纳米颗粒（AuNPs）,再通过滴干修饰法研制了Nafion/GOx-AuNPs修饰的玻碳（GC）电极,并考察了该酶电极上GOx的直接电化学和生物传感性能. 这种酶法合成的GOx-AuNPs复合物有良好的酶直接电化学活性,也保持了GOx的生物活性,似可归因于酶法合成的纳米金更接近酶氧化还原活性中心的缘故. 该酶电极在-0.4 V（vs. SCE）电位下,其稳态电流下降与葡萄糖浓度（0.5 4 mmol·L^-1）成正比,检测下限0.2 mol·L^-1.     

Ultrasonic assisted synthesis of nanocrystalline cellulose as support and reducing agent for Ag nanoparticles: green synthesis and novel effective nanocatalyst for degradation of organic dyes

In this study, nanocrystalline cellulose (NCC) prepared from microcrystalline cellulose using high‐intensity ultrasonication as mechanical method without any chemical treatment. The obtained NCC with around 30–50 nm diameters, utilized as support, reducing and stabilizing agent for in‐situ green and eco‐friendly synthesis of silver nanoparticles (Ag NPs). The catalytic activity of composite was examined for degradation of environmental pollutants. The structure of as‐synthesized composite (Ag@NCC) was characterized by ultraviolet–visible spectroscopy (UV–vis), field emission scanning electron microscopy (FE‐SEM); Transmission electron microscopy (TEM); Energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD) and thermogravimetric analysis (TGA). The results of the catalytic reaction experiments showed that spherically shaped silver nanoparticles of around 20 nm distributed on the surface of nanocellulose demonstrated high catalytic efficiency towards the removal of methyl orange (MO) and 4‐nitrophenol (4‐NP).     

Colloidal stability evolution and completely reversible aggregation of gold nanoparticles functionalized with rationally designed free radical initiators

A series of molecular adsorbates having various chain lengths of terminal poly(ethylene glycol methyl ether) (PEG) moieties, thiol head groups, and intervening free radical initiator moieties was used to functionalize the surface of gold nanoparticles (AuNPs). The bulky PEG groups stabilized the functionalized AuNPs by providing steric hindrance against AuNP aggregation, such aggregation being a major problem in the modification and manipulation of metal nanoparticles. UV–vis spectroscopy was used to evaluate the stability of the adsorbate-functionalized AuNPs as a function of AuNP size (～15, 40, and 90 nm in diameter) and PEG chain length (Mn 350, 750, and 2,000). The longer PEG chains (Mn 750 and 2,000) afforded stability to AuNPs with smaller gold cores (～15 and 40 nm in diameter) for up to several days without any marked aggregation. In contrast, the adsorbate-functionalized AuNPs with the largest gold cores (～90 nm) were noticeably less stable than those with the smaller gold cores. Importantly, the adsorbate-functionalized AuNPs could be isolated in solvent-free “dried” form and readily dispersed in aqueous buffer solution (both acidic and basic) and various organic solvents (protic and aprotic). This isolation–redispersion (i.e., aggregation/deaggregation) process was completely reversible. The chemisorption of the PEG-terminated initiator on the surface of the AuNPs was verified by Fourier transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS). As a whole, the strategy reported here affords colloidally stable, free radical initiator-functionalized AuNPs and offers a promising general method for encapsulating metal nanoparticles within polymer shells.

Preparation,characterization and catalytic activity of biomaterial-supported copper nanoparticles

Synthesis of copper nanoparticles was carried out with nanocrystalline cellulose (NCC) as a support by reducing CuSO₄·5H₂O ions using hydrazine. Ascorbic acid and aqueous NaOH were also used as an antioxidant and pH controller, respectively. The synthesized copper nanoparticles supported on NCC (CuNPs@NCC) were characterized by UV–vis, XRD, TEM, XRF, TGA, DSC, N₂ adsorption-desorption method at 77 K and FTIR. The UV–vis confirmed the formation and stability of the CuNPs, which indicated that the maximum absorbance of CuNPs@NCC was at 590 nm due to the surface plasmon absorption of CuNPs. Morphological characterization clearly showed the formation of a spherical structure of the CuNPs with the mean diameter and standard deviation of 2.71 ± 1.12 nm. Similarly, XRD showed that the synthesized CuNPs@NCC was of high purity. The thermal analysis showed that the CuNPs@NCC exhibited better thermal behaviors than NCC. BET surface area revealed that the N₂ adsorption–desorption isotherms of CuNPs@NCC featured a type IV isotherm with an H3 hysterisis loop. This chemical method is simple, cost effective, and environmentally friendly. Compared to NCC-supported CuNPs and unsupported CuNPs, the as-prepared CuNPs@NCC exhibit a superior catalytic activity and high sustainability for the reduction of methylene blue with NaBH₄ in aqueous solution at room temperature. The CuNPs@NCC achieved complete reduction of MB with completion time, rate constant and correlation coefficient (R ²) of 12 min, 0.7421 min^?1 and 0.9922, respectively.     

Glucose biosensor based on a platinum electrode modified with rhodium nanoparticles and with glucose oxidase immobilized on gold nanoparticles

We have developed an enzymatic glucose biosensor that is based on a flat platinum electrode which was covered with electrophoretically deposited rhodium (Rh) nanoparticles and then sintered to form a large surface area. The biosensor was obtained by depositing glucose oxidase (GOx), Nafion, and gold nanoparticles (AuNPs) on the Rh electrode. The electrical potential and the fractions of Nafion and GOx were optimized. The resulting biosensor has a very high sensitivity (68.1 μA mM^?1 cm^?2) and good linearity in the range from 0.05 to 15 mM (r?=?0.989). The limit of detection is as low as 0.03 mM (at an SNR of 3). The glucose biosensor also is quite selective and is not interfered by electroactive substances including ascorbic acid, uric acid and acetaminophen. The lifespan is up to 90 days. It was applied to the determination of glucose in blood serum, and the results compare very well with those obtained with a clinical analyzer.

Voltammetric study on pristine and nitrogen-doped multi-walled carbon nanotubes decorated with gold nanoparticles

Films consisting of pristine multi-walled carbon nanotubes (MWCNTs) and nitrogen-doped MWCNTs (N-MWCNTs) were fabricated by means of chemical vapor deposition and chemically decorated with gold nanoparticles (AuNPs). Optical microscopy and image analysis reveal that the deposited AuNPs have diameters of 50–200 nm and 100–400 nm, respectively. The AuNP-modified films of MWCNTs and of N-MWCNTs were initially investigated with respect to their response to the ferro/ferricyanide redox system. The N-MWCNTs/AuNPs exhibit lower detection limit (0.345 μM) for this redox system compared to that of MWCNTs/AuNPs (0.902 μM). This is probably due to the presence of nitrogen that appears to enhance the electrocatalytic activity of MWCNTs. The findings demonstrate that the electrochemical responses of both films are distinctly enhanced upon deposition of AuNPs on their surfaces. The detection limits of MWCNTs/AuNPs and N-MWCNTs/AuNPs systems are lower by about 43 % and 27 %, respectively, compared to films not modified with AuNPs. The electrocatalytic activity of the films towards the oxidation of ascorbic acid (AA), uric acid (UA), and dopamine (DA) was studied. The findings reveal that N-MWCNTs/AuNPs represent a powerful analytical tool that enables simultaneous analysis of AA, UA, and DA in a single experiment.

Optical determination of glucose and hydrogen peroxide using a nanocomposite prepared from glucose oxidase and magnetite nanoparticles immobilized on graphene oxide

Fe₃O₄ nanoparticles were deposited on sheets of graphene oxide (GO) by a precipitation method, and glucose oxidase (GOx) was then immobilized on this material to produce a GOx/Fe₃O₄/GO magnetic nanocomposite containing crosslinked enzyme clusters. The 3-component composite functions as a binary enzyme that was employed in a photometric method for the determination of glucose and hydrogen peroxide where the GOx/Fe₃O₄/GO nanoparticles cause the generation of H₂O₂ which, in turn, oxidize the substrate N,N-diethyl-p-phenylenediamine to form a purple product with an absorption maximum at 550 nm. The absorbance at 550 nm can be correlated to the concentration of glucose and/or hydrogen peroxide. Under optimized conditions, the calibration plot is linear in the 0.5 to 600 μM glucose concentration range, and the detection limit is 0.2 μM. The respective plot for H₂O₂ ranges from 0.1 to 10 μM, and the detection limit is 0.04 μM. The method was successfully applied to the determination of glucose in human serum samples. The GOx/Fe₃O₄/GO nanoparticles are reusable.

Preparation and nonlinear optical properties of Au nanoparticles doped TiO2 thin films

Nano-sized noble metal nanoparticles doped dielectric composite films with large third-order nonlinear susceptibility due to the confinement and the enhancement of local field were considered to be applied for optical information processing devices, such as optical switch or all optical logical gates. In this paper, sol–gel titania thin films doped with gold nanoparticles (AuNPs, ~10 nm in average size) were prepared. AuNPs were firstly synthesized from HAuCl₄ in aqueous solution at ~60 °C, using trisodium citrate as the reducing agent, polyvinylpyrrolidone as the stable agent; then the particle size and optical absorption spectra of the AuNPs in aqueous solutions were characterized by transmitting electron microscopy and UV–Vis–NIR spectrometry. Sol–gel 2AuNPs–100TiO₂ (in %mol) thin films (5 layers, ~1 μm in thickness) were deposited on silica glass slides by multilayer dip-coating. After heat-treated at 300–1,000 °C in air, the AuNPs–TiO₂ thin films were investigated by X-ray diffraction, scanning electron microscopy and atomic force microscopy. The nonlinear optical properties of the AuNPs–TiO₂ thin films were measured with the Z-scan technique, using a femtosecond laser (200 fs) at the wavelength of 800 nm. The third-order nonlinear refractive index and nonlinear absorption coefficient of 2AuNPs–100TiO₂ films were at the order of 10^?12 cm²/W, and the order of 10^?6 cm/W, respectively, and the third-order optical nonlinear susceptibility χ⁽³⁾ was ~6.88 × 10^?10 esu.     

Disposable electrochemical immunosensor for myeloperoxidase based on the indium tin oxide electrode modified with an ionic liquid composite film containing gold nanoparticles, poly(o-phenylenediamine) and carbon nanotubes

A disposable electrochemical myeloperoxidase (MPO) immunosensor was fabricated based on the indium tin oxide electrode modified with a film composed of gold nanoparticles (AuNPs), poly(o-phenylenediamine), multi-walled carbon nanotubes and an ionic liquid. The composite film on the surface of the electrode was prepared by in situ electropolymerization using the ionic liquid as a supporting electrolyte. Negatively charged AuNPs were then adsorbed on the modified electrode via amine-gold affinity and to immobilize MPO antibody. Finally, bovine serum albumin was employed to block possible remaining active sites on the AuNPs. The modification of the electrode was studied by cyclic voltammetry and scanning electron microscopy. The factors affecting the performance of the immunosensor were investigated in detail using the hexacyanoferrate redox system. The sensor exhibited good response to MPO over two linear ranges (from 0.2 to 23.4 and from 23.4 to 300 ng.mL^?1), with a detection limit of 0.05 ng.mL^?1 (at an S/N of 3).

Screen-printed enzymatic glucose biosensor based on a composite made from multiwalled carbon nanotubes and palladium containing particles

A composite material consisting of multiwalled carbon nanotubes and palladium containing particles was synthesized and applied to the preparation of bulk-modified screen-printed carbon electrodes (Pd-MWCNT-SPCE) and surface-modified screen-printed carbon electrodes (Pd-MWCNT/SPCE). They were characterized by cyclic voltammetry and hydrodynamic chronoamperometry in solution of pH 7.5. Both electrodes were then modified with glucose oxidase (GOx) by drop-coating a solution of GOx and Nafion® on their surface. Glucose can be determined via enzymatically formed H₂O₂. In an alternative approach, gold nanoparticles (5 nm) were incorporated into the biolayer of the electrodes. The resulting electrodes of type GOx/Pd-MWCNT-SPCE and GOx-Au/Pd-MWCNT-SPCE showed acceptable analytical performance at working potentials between ?0.20 V and ?0.50 V in case of hydrodynamic chronoamperometry. Both electrodes can be operated best at a working potential of ?0.40 V vs SCE, with acceptable linearity of the methods in sub mM concentration ranges and with LOQs of 0.14 mM and 0.07 mM for glucose for the GOx/Pd-MWCNT-SPCE and GOx-Au/Pd-MWCNT-SPCE, respectively. Incorporation of gold nanoparticles prolongs the operational lifetime of the electrodes by two weeks. The GOx/Pd-MWCNT-SPCE based method was applied to the determination of glucose in multifloral honey, and the GOx-Au/Pd-MWCNT-SPCE method to the determination of glucose in blood serum. In both cases there was a good agreement with the results obtained by commercially available equipment for determination of glucose.

Open image in new window

Graphical abstract Schematic of a screen printed carbon biosensor based on the use of multiwalled carbon nanotubes modified with palladium-containing particles and glucose oxidase. It can be applied to the amperometric determination of glucose in blood serum and multifloral honey

     

Construction of a biointerface for glucose oxidase through diazonium chemistry and electrostatic self-assembly technique

In this study, a new procedure for the fabrication of biosensors was developed. The method is based on the covalent attachment of nitrophenyl groups to the electrode surface via diazonium salt reaction followed by their conversion to amine moieties through electrochemical reduction and electrostatic layer-by-layer (LbL) assembly technique. In this procedure, highly stable iron oxide (Fe₃O₄) nanoparticles (IONPs), chitosan (CHIt), GOx, and Nile blue (NB) were assembled on the surface of aminophenyl modified glassy carbon electrode (AP/GCE) by LbL assembly technique. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to characterize the interfaces. The surface coverage of the active GOx and Michaelis–Menten constant (K _M) of the immobilized GOx were Γ?=?3.38?×?10^?11 mol cm^?2 and 2.54 mM, respectively. The developed biosensor displayed a well-defined amperometric response for glucose determination with high sensitivity (8.07 μA mM^?1) and low limit of detection (LOD) of 19.0 μM. The proposed approach allows simple biointerface regeneration by increasing pH which causes disruption of the ionic interactions and release of the electrostatic attached layers. The biosensor can then be reconstructed again using fresh enzyme. Simple preparation, good chemical and mechanical stabilities, and easy surface renewal are remarkable advantages of the proposed biosensor fabrication procedure.     

Nitrogen-doped carbon nanotubes modified with gold nanoparticles for simultaneous analysis of N-acetylcysteine and acetaminophen

A novel film consisting of nitrogen-doped multi-walled carbon nanotubes modified with gold nanoparticles (further denoted as N-MWCNTs/AuNPs) was fabricated and applied for the simultaneous electrochemical analysis of N-acetylcysteine (NAC) and acetaminophen (AC) in phosphate buffer solution (PBS, pH 7.0). The fabricated film exhibits powerful response towards simultaneous analysis of NAC and AC followed by well-separated cyclic voltammetric waves (～440 mV). The oxidation peak currents of NAC and AC increase linearly with their concentrations in the ranges of 0.100–1.510 mM and 0.063–0.190 mM, respectively. The detection limits of N-MWCNTs/AuNPs towards NAC and AC were estimated to be 3.0 and 0.35 μM, respectively. The good catalytic activity, the high detection ability, and the great stability of N-MWCNTs/AuNPs verify that such composite materials are extremely promising for the construction of biosensors.     

Fast preparation of nanocrystalline cellulose by microwave-assisted hydrolysis

In this work we report on the procedure for fast and controlled preparation of nanocrystalline cellulose (NCC) from commercially available microcrystalline cellulose using microwave-assisted hydrolysis. By varying the sulfuric acid concentration and hydrolysis temperature, an average hydrodynamic diameter of NCC between 126 and 1,310 nm with corresponding yields between 16 and 82 %, respectively, was obtained in a very short reaction time of 10 min. An additional advantage of the described procedure is its high reproducibility and ability to fine-tune the average NCC particle size by adjusting the reaction conditions, i.e., the sulfuric acid concentration and/or reaction temperature.     

A glassy carbon electrode modified with graphene, gold nanoparticles and chitosan for ultrasensitive determination of lead(II)

We have modified a glassy carbon electrode by single-step electrodeposition of graphene (GR), gold nanoparticles (AgNPs), and chitosan (CS) directly from a solution containing graphene oxide, tetrachloroauric acid, and chitosan. The surface and electrochemical properties of the film-modified electrode were investigated by SEM and TEM images. The AuNPs have a diameter of about 20 nm and are uniformly dispersed in the matrix. Combining the advantages of GR (i.e., high surface area and conductivity), of AuNPs (excellent electrical conductivity) and CS (excellent film-forming ability and good water permeability), the hybrid film effectively enhances electron-transfer and promotes the response to lead(II) ion. Under the optimum conditions, a linear relationship exists between electrical current and the concentration of lead (II) ion in the range between 0.5 to 100 μg?L-1, with a detection limit of 1 ng?L-1 (at an SNR of 3). The electrode was successfully applied to the detection of lead(II) in spiked samples of river water.

Immobilization of Recombinant Human Catalase on Gold and Silver Nanoparticles

Human catalase cDNA was cloned into a pEX-C-His vector. Purified recombinant catalase was immobilized on nanoparticles. Gold and silver nanoparticles were synthesized in a variety of sizes by chemical reduction; no agglomerates or aggregates were observed in any of the colloids during dynamic light scattering or scanning transmission electron microscopy analysis. After immobilization on gold nanoparticles, recombinant catalase activity was found to be lower than that of the same amount of enzyme in aqueous solution. However, after 10 days of storage at room temperature, the activity of catalase immobilized on gold nanoparticles (AuNPs) of 13 and 20 nm and coverage of 133% was 68 and 83% greater than catalase in aqueous solution, respectively. During 10 days of experiment, percentage activity of catalase immobilized on those gold nanoparticles was higher in comparison to CAT in aqueous solution. Catalase immobilized on silver nanoparticles did not lose activity as significantly as catalase immobilized on AuNPs. Those results confirm the ability to produce recombinant human enzymes in a bacterial expression system and its potential use while immobilized on silver or gold nanoparticles.     

Ultrasound assisted biobleaching of cotton

In this study, the effect of ultrasound on the activity of the glucose oxidase (GOx) enzyme for bleaching of the cotton fabrics was investigated. Hydrogen peroxide generation with the GOx enzyme from glucose was carried out under ultrasonic homogenizer (UH) and ultrasonic bath support. The aim of using ultrasonic support was to increase the yield of the enzyme reactions. The enzymatically generated hydrogen peroxide was used for bleaching of cotton fabrics. The bleaching process was performed at 90 °C and pH 11 (with NaOH) for 60 min, followed by rinsing at 70 and 50 °C then cold washing. The whiteness degrees of the cotton samples that were bleached by the generated peroxide were compared to the whiteness degrees of the conventionally bleached cotton fabrics. Sufficient whiteness degrees in cotton fabrics could be obtained by enzymatically generated hydrogen peroxide by UH support. The initial whiteness degree of the cotton fabric was 59.9 Stensby degrees; the whiteness was increased to 75.6 Stensby degrees by the GOx enzyme under UH support where the conventional bleaching process yielded a whiteness value of 76.7 Stensby degrees. For efficient cotton bleaching by the GOx enzyme, UH support contributed to the concentration of enzymatically generated hydrogen peroxide by the GOx enzyme. Bleaching of cotton by the GOx enzyme was approved as a more environmentally friendly process compared to the conventional bleaching method in respect of the results of chemical oxygen demand tests.     

Tin disulfide nanoflakes decorated with gold nanoparticles for direct electrochemistry of glucose oxidase and glucose biosensing

Previously, we have prepared nanoflake-like tin disulfide (SnS2) and used for the immobilization of proteins and biosensing. We have now modified an electrode with a composite consisting of nanoflake-like SnS2 decorated with gold nanoparticles (Au-NPs) and have immobilized glucose oxidase (GOx) on its surface in order to study its direct electrochemistry. Scanning electron microscopy, electrochemical impedance spectroscopy, Fourier transform IR spectroscopy and cyclic voltammetry were used to examine the interaction between GOx and the AuNP-SnS2 film. It is shown that the composite film has a larger surface area and offers a microenvironment that facilitates the direct electron transfer between enzyme and electrode surface. The immobilized enzyme retains its bioactivity and undergoes a surface-controlled, reversible 2-proton and 2-electron transfer reaction, with an apparent electron transfer rate constant of 3.87 s ^-1. Compared to the nanoflake-like SnS2-based glucose sensor, the GOx-based biosensor exhibits a lower detection limit (1.0 :M), a better sensitivity (21.8 mA?M ^-1 ?cm ^-2), and a wider linear range (from 0.02 to 1.3 mM). The sensor displays excellent selectivity, good reproducibility, and acceptable stability. It was successfully applied to reagentless sensing of glucose at ?0.43 V.

Preparation of nanoscale cellulose materials with different morphologies by mechanical treatments and their characterization

Rod-like cellulose nanowhiskers and spherical cellulose nanoparticles were prepared from wood-pulp-derived cellulose powder by mechanical refining processes such as high-pressure homogenization (HPH) and ball-milling (BM). The nanowhiskers obtained by the HPH method were found to be 200–500 nm long and 11–16 nm wide. The diameters of the nanoparticles were in the range 40–200 nm, depending on the BM time, and were reduced to 25–50 nm after extra HPH. By adjusting the BM time, cellulose nanoparticles having different polymorphs with similar morphologies were prepared. The X-ray diffraction patterns revealed the recrystallization of cellulose I (1 h of BM time) or cellulose II (4–8 h of BM time) in ball-milled nanoparticles after water washing and solvent exchange treatments. The nanowhisker widths derived from the specific surface areas (SSA) by adsorption methods such as Congo red dye, nitrogen, and water vapor, sorptions were in agreement with those obtained from transmission electron microscopy and atomic force microscopy images. Similar SSA values were obtained for micro- and nano-scale cellulose materials using water vapor adsorption methods, and the SSAs of nanoparticles obtained by different adsorption methods are also discussed.     

Preparation and characterization of nanocrystalline cellulose via low-intensity ultrasonic-assisted sulfuric acid hydrolysis

Nanocrystalline cellulose (NCC) was extracted from microcrystalline cellulose via low-intensity ultrasonic-assisted sulfuric acid hydrolysis process. NCC samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), particle size distribution (PSD) analysis, Fourier-transformed infrared spectra (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and rheological measurement. It was found that NCC yield reached 40.4 % under the optimum process of low-intensity ultrasonic-assisted sulfuric acid hydrolysis, while it was only 33.0 % in the absence of ultrasonic treatment. Furthermore, the results showed that the two NCC samples obtained from ultrasonic-assisted hydrolysis and conventional hydrolysis were very similar in morphology, both exhibiting rod-like structures with widths and lengths of 10–20 and 50–150 nm, respectively. XRD result revealed that the NCC sample from ultrasonic-assisted hydrolysis contained a small amount of cellulose II and possessed a Segal Crystallinity Index of 90.38 % and a crystallite size of 58.99 Å, higher than those of the NCC sample from conventional hydrolysis. Moreover, PSD analysis demonstrated that the former exhibited a smaller value in average particle size than the latter. In addition, rheological measurements showed that the NCC suspensions from the ultrasonic-assisted process exhibited a lower viscosity over the range of shear rate from 0.1 to 100 s^?1 in comparison with that prepared in the absence of ultrasonic treatment.     

Electrochemical glucose biosensor based on silver nanoparticles/multiwalled carbon nanotubes modified electrode

A novel glucose biosensor was fabricated by immobilizing glucose oxidase (GOx) on Ag nanoparticles-decorated multiwalled carbon nanotube (AgNP-MWNT) modified glass carbon electrode (GCE). The AgNP-MWNT composite membrane showed an improving biocompatibility for GOx immobilization and an enhancing electrocatalytic activity toward reduction of oxygen due to decoration of AgNPs on MWNT surfaces. The AgNPs also accelerated the direct electron transfer between redox-active site of GOx and GCE surface because of their excellent conductivity and large capacity for protein loading, leading to direct electrochemistry of GOx. The glucose biosensor of this work showed a lower limit of detection of 0.01 mM (S/N?=?3) and a wide linear range from 0.025 to 1.0 mM, indicating an excellent analytical performance of the obtained biosensor to glucose detection. The resulting biosensor exhibits good stability and excellent reproducibility. Such bionanocomposite provides us good candidate material for fabrication of biosensors based on direct electrochemistry of immobilized enzymes.