Yingchun Fu

Hunan University, Changsha, Hunan, China

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Publications (34)144.79 Total impact

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    ABSTRACT: Learning from nature is one of the most promising ways to develop advanced functional materials. Here, inspired by blood coagulation, novel fibrin-boned bionanocomposites are reported as efficient immobilization matrices of biomacromolecules and nanomaterials for biosensing. Glucose oxidase (GOx), Au nanoparticles (AuNPs), and Fe3O4 magnetic nanoparticles (MNPs) are adopted as the model biomacromolecules and nanomaterials. By integrating the thrombin-triggered coagulation of fibrin with advanced surficial modification techniques, four kinds of immobilization strategies are developed and evaluated. Digital imaging, UV-vis spectroscopy, scanning/transmission electron microscopy, electrochemical methods, and N2 adsorption-desorption isotherms are used to investigate the formation, immobilization efficiency, and performance of various bionanocomposites. The fibrin-boned networks show inherent biocompatibility, excellent adsorbability, porosity, and functionalization ability, endowing the bionanocomposites with high efficiencies in capturing AuNPs, MNPs and GOx (99%, 98%, and 57% captured under the given conditions, respectively), as well as significant mass-transfer and biocatalysis efficiencies. Therefore, the fibrin-boned bionanocomposites show great potential for biosensing, for example, a fibrin-AuNPs-GOx-glutaraldehyde bionanocomposites modified Au electrode is highly sensitive to glucose (145 μA cm−2 mM−1) allowing for a limit of detection down to 25 nM, being much superior to those of the reported analogues. The presented experimental platform/strategy may find wide applications in the development of other bio/nano-materials/devices.
    Advanced Functional Materials 05/2014; · 10.44 Impact Factor
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    ABSTRACT: Facile filling of multiwalled carbon nanotubes (MWCNTs) with Prussian blue nanoparticles (PBNPs) of high peroxidase-like catalytic activity was performed to develop novel colorimetric sensing protocols for assaying H2 O2 and glucose. Fine control of PBNP growth was achieved by modulating the concentration ratio of K3 [Fe(CN)6 ] and FeSO4 precursors in an acidic solution containing ultrasonically dispersed MWCNTs, and thus size-matched PBNPs could be robustly immobilized in the cavities of the MWCNTs (MWCNT-PBin ). Unlike other reported methods involving complicated procedures and rigorous preparation/separation conditions, this mild one-pot filling method has advantages of easy isolation of final products by centrifugation, good retention of the pristine outer surface of the MWCNT shell, and satisfactory filling yield of (24±2) %. In particular, encapsulation of PBNPs of poor dispersibility and limited functionality in dispersible and multifunctional MWCNT shells creates new and valuable opportunities for quasihomogeneous-phase applications of PB in liquid solutions. The MWCNT-PBin nanocomposites were exploited as a peroxidase mimic for the colorimetric assay of H2 O2 in solution by using 3,3',5,5'-tetramethylbenzidine (TMB) as reporter, and they gave a linear absorbance response from 1 μM to 1.5 mM with a limit of detection (LOD) of 100 nM. Moreover, glucose oxidase (GOx) was anchored on the outer surface of MWCNT-PBin to form GOx/MWCNT-PBin bionanocomposites. The cooperation of outer-surface biocatalysis with peroxidase-like catalysis of interior PB resulted in a novel cooperative colorimetric biosensing mode for glucose assay. The use of GOx/MWCNT-PBin for colorimetric biosensing of glucose gave a linear absorbance response from 1 μM to 1.0 mM and an LOD of 200 nM. The presented protocols may be extended to other multifunctional nanocomposite systems for broad applications in catalysis and biotechnology.
    Chemistry 01/2014; · 5.93 Impact Factor
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    ABSTRACT: Hierarchical porous Fe3O4 particles with tunable grain size were synthesized based on a facile poly (diallyldimethylammonium chloride) (PDDA)-modulated solvothermal method. The products were characterized with scanning electron microscopy (SEM) and transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), N2 adsorption-desorption technique, vibrating sample magnetometer (VSM), and dynamic light scattering (DLS). The results show that increasing the PDDA dosage decrease the grain size and particle size, which increased the particle porosity and enhanced the surface area from 7.05 to 32.75 m2 g-1. Possible mechanism can be ascribed to the PDDA function on capping the crystal surface and promoting the viscosity of reaction medium to mediate the growth and assembly of grain. Furthermore, the arsenic adsorption application of the as-obtained Fe3O4 samples was investigated and the adsorption mechanism was proposed. High magnetic Fe3O4 particles with increased surface area display improved arsenic adsorption performance, superior efficiency in low-level arsenic removal, high desorption efficiency and satisfactory magnetic recyclability, which are very promising compared with commercial Fe3O4 particles.
    ACS Applied Materials & Interfaces 11/2013; · 5.01 Impact Factor
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    ABSTRACT: Enzymatic catalysis is broadly used in various fields but generally applied in media with high ion strength. Here we propose the exploitation of the enzymatic catalysis in ultra-low ion strength media to induce ion strength increase for developing a novel impedance biosensing method. Avian Influenza virus H5N1, a serious worldwide threat to poultry and human health, was adopted as the analyte. Magnetic beads were modified with H5N1-specific aptamer to capture the H5N1 virus. This was followed by binding Concanavalin A (ConA), Glucose oxidase (GOx), and Au nanoparticles (AuNPs) to create bionanocomposites through ConA-glycan interaction. The yielded sandwich complex was transferred to a glucose solution to trigger an enzymatic reaction to produce gluconic acid, which ionized to increase the ion strength of the solution, thus decreasing the impedance on a screen-printed interdigitated array electrode. This method took advantages of the high efficiency of enzymatic catalysis and the high susceptibility of electrochemical impedance on the ion strength, and endowed the biosensor with high sensitivity and a detection limit of 8  10-4 HAU in 200 L sample, which was magnitudes lower than that of some analogues based on biosensing methods. Furthermore, the proposed method required only a bare electrode for measurements of ion strength change and had negligible change on the surficial properties of the electrode, though some modification of magnetic beads/Au nanoparticles and the construction of a sandwich-complex were still needed. This helped to avoid the drawbacks of commonly used electrode-immobilization methods. The merit for this method makes it highly useful and promising for applications. The proposed method may create new possibilities in the broad and well-developed enzymatic catalysis fields and find applications in developing sensitive, rapid, low-cost, easy-to-operate biosensing and biocatalysis devices.
    Analytical Chemistry 11/2013; · 5.70 Impact Factor
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    ABSTRACT: Acrylamide is a neurotoxin and potential carcinogen, but is found in various thermally processed foods such as potato chips, biscuits, and coffee. Simple and sensitive methods for on-line detection of acrylamide are needed to ensure food safety. In this paper, a novel fluorescent sensing method based on acrylamide polymerization-induced distance increase between quantum dots (QDs) was proposed for detecting acrylamide in potato chips. The functional QDs were prepared by their binding with N-acryloxysuccinimide (NAS), which was characterized by Fourier transform infrared (FR-IR) spectra. The carbon-carbon double bonds of NAS modified QDs polymerized with assistance of photo initiator under UV irradiation, leading to QDs getting closer along with fluorescence intensity decreasing. Acrylamide in the sample participated in the polymerization and induced an increase of fluorescence intensity. This method possessed a linear range from 3.5×10(-5) to 3.5gL(-1) (r(2)=0.94) and a limit of detection of 3.5×10(-5)gL(-1). Although the sensitivity and specificity cannot be compared with standard LC-MS/MS analysis, this new method requires much less time and cost, which is promising for on-line rapid detection of acrylamide in food processing.
    Biosensors & bioelectronics 10/2013; 54C:64-71. · 5.43 Impact Factor
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    ABSTRACT: Glucose detection is of great significance in biomedical applications. Principles, methods and recent developments in electrochemical glucose sensors are reviewed here. Special attention is given to the discussion on some problems and bottlenecks in areas of nonenzymatic and enzymatic (glucose oxidase-based) amperometric glucose sensing.
    RSC Advances 03/2013; 3(14):4473-4491. · 3.71 Impact Factor
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    ABSTRACT: We report on the thiol–ene chemistry guided preparation of a novel thiolated polymeric nanocomposite involving polyaniline (PANI), a functionalized thiol, e.g., sulfur-rich 2,5-dimercapto-1,3,4-thiadiazole (DMcT), and multiwalled carbon nanotubes (MWCNTs) for the sensitive differential pulse anodic stripping voltammetric determination of Cd2+ and Pb2+ on a glassy carbon electrode (GCE). Briefly, the thiol–ene reaction of a thiol with oxidized PANI that was chemically synthesized in the presence of solution-dispersed acidified MWCNTs yielded a thiolated polymeric nanocomposite of thiol-PANI/MWCNTs. The thiols examined include DMcT, 1,6-hexanedithiol and β-mercaptoethanol. Quartz crystal microbalance, cyclic voltammetry, scanning electron microscopy, Fourier transform infrared spectroscopy and ultraviolet-visible spectroscopy were used for film characterization and process monitoring. Under the optimized conditions, the obtained Bi/Nafion/DMcT–PANI/MWCNTs/GCE can sensitively sense Cd2+ and Pb2+ with limits of detection of 0.01 and 0.04 μg L−1, respectively.
    The Analyst 01/2013; 138(4). · 4.23 Impact Factor
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    ABSTRACT: We report here on a facile enzymatic polymerization protocol to prepare enzyme-poly(thiophene-3-boronic acid) (PTBA) polymeric biocomposites (PBCs) for high-performance mono-/bi-enzyme amperometric biosensing. Horseradish peroxidase (HRP)-catalyzed polymerization of thiophene-3-boronic acid (TBA) monomer was conducted in aqueous solution containing HRP (or plus glucose oxidase (GOx)) by either directly added or GOx-glucose generated oxidant H(2)O(2). The mono-/bi-enzyme amperometric biosensors were prepared simply by casting the dialysis-isolated PBCs on Au-plated Au electrode (Au(plate)/Au), followed by coating with an outer-layer chitosan (CS) film. The boronic acid residues are capable of covalent bonding with enzyme at the glycosyl sites (boronic acid-diols interaction), which should less affect the enzymatic activity as compared with the common cases of covalent bonding at the peptide chains, and UV-vis spectrophotometric tests confirmed that the encapsulated HRP almost possesses its pristine enzymatic specific activity. The enzyme electrodes were studied by cyclic voltammetry, electrochemical impedance spectroscopy and chronoamperometry in the presence of Fe(CN)(6)(4-) mediator. The CS/HRP-PTBA/Au(plate)/Au electrode responded linearly to H(2)O(2) concentration from 1 to 300μM with a sensitivity of 390μAmM(-1)cm(-2) and a limit of detection (LOD) of 0.1μM. The bienzyme CS/GOx-HRP-PTBA(H(2)O(2))/Au(plate)/Au electrode responded linearly to glucose concentration from 5μM to 0.83mM with a sensitivity of 75.1μAmM(-1)cm(-2) and a LOD of 1μM, and it is found here that the use of Fe(CN)(6)(4-) that can only efficiently mediate HRP favorably avoids the "unusual amperometric responses" observed when other mediators that can efficiently turn over both HRP and GOx are used.
    Biosensors & bioelectronics 01/2013; 44C:41-47. · 5.43 Impact Factor
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    ABSTRACT: We report on the thiol-ene chemistry guided preparation of a novel thiolated polymeric nanocomposite involving polyaniline (PANI), a functionalized thiol, e.g., sulfur-rich 2,5-dimercapto-1,3,4-thiadiazole (DMcT), and multiwalled carbon nanotubes (MWCNTs) for the sensitive differential pulse anodic stripping voltammetric determination of Cd(2+) and Pb(2+) on a glassy carbon electrode (GCE). Briefly, the thiol-ene reaction of a thiol with oxidized PANI that was chemically synthesized in the presence of solution-dispersed acidified MWCNTs yielded a thiolated polymeric nanocomposite of thiol-PANI/MWCNTs. The thiols examined include DMcT, 1,6-hexanedithiol and β-mercaptoethanol. Quartz crystal microbalance, cyclic voltammetry, scanning electron microscopy, Fourier transform infrared spectroscopy and ultraviolet-visible spectroscopy were used for film characterization and process monitoring. Under the optimized conditions, the obtained Bi/Nafion/DMcT-PANI/MWCNTs/GCE can sensitively sense Cd(2+) and Pb(2+) with limits of detection of 0.01 and 0.04 μg L(-1), respectively.
    The Analyst 01/2013; · 4.23 Impact Factor
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    ABSTRACT: We report on a novel label-free biosensing interface based on multi-functional polymeric bionanocomposites (PBNCs) and its application for sensitive detection of protein based on the analytes-induced suppression of enzymatic catalysis in PBNCs. Thrombin and its aptamer are adopted as the model system (aptasensor). First, polydopamine-based PBNCs with glucose oxidase (GOx) entrapped in high load/activity and Au nanoparticles (AuNPs) dispersed in high abundance on the surface were prepared through a chemical/biochemical synthesis method, as proved by UV-vis spectrophotometry, digital imaging, and transmission electron microscopy. Then the PBNCs were cast-coated onto the Au electrode. The PBNCs modified electrode presented sensitivity of chronoamperometric response as high as 113  2 A cm-2 mM-1 to glucose, as well as high immobilization ability to aptamers through the surficial AuNPs to fabricate a label-free aptasensing interface. The binding of thrombin to the aptasensor significantly hindered the mass-transfer of the enzymatic substrates/products and thus suppressed the enzymatic catalysis efficiency, which produced obvious signal change through measuring the electrooxidation of enzymatically generated H2O2. The thus-prepared aptasensor could detect thrombin with a broad detection range (1-100 nM), a detection limit down to 0.1 nM, and satisfactory specificity. The developed aptasensing method may find broad applications in the fields of clinic diagnosis, environmental protection, and food safety.
    ACS Applied Materials & Interfaces 12/2012; · 5.01 Impact Factor
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    ABSTRACT: Au-supported Pt-Au mixed atomic monolayer electrocatalyst was prepared by underpotential deposition of Cu on Au and then redox replacement with noble metal atoms, which shows an ultrahigh Pt-mass (or Pt-area) normalized specific electrocatalytic activity of 102 mA μg(Pt)(-1) (124 mA cm(Pt)(-2)) for oxidation of formic acid in acidic aqueous solution.
    Chemical Communications 11/2012; · 6.38 Impact Factor
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    ABSTRACT: We report on mild and selective filling of multiwalled carbon nanotubes (MWCNTs) with Prussian blue (PB) to explore the filling/electrochemistry/mass-transfer in nanochannels and the biosensing mode of nanochannel interior-exterior cooperation. PB-filled MWCNTs (MWCNTs-PBin) are prepared by filling MWCNTs with the gradually growing PB and then selectively removing the outer-surface PB by careful chemical washing. The prepared MWCNTs-PBin composites possess high filling yield (mass ratio of PB to MWCNTs, (30 ± 3)%) and electroactivity percentage (mass ratio of electroactive PB to total PB, (45 ± 3)%). The MWCNTs-PBin composites on Au electrode exhibit strong and stable electrocatalytic activity of filled PB for H2O2 reduction and electroanalysis. The filling of the MWCNTs with electroactive PB also provides a new experimental platform to deal with the widely concerned issue of mass transfer inside nanochannels. The normalized cyclic voltammetric responses of filled PB on MWCNTs-PBin electrode at relatively low scan rates (below 125 and 75 mV s–1 for mass transfer of K+ and K+ + H2O2, respectively) were found to be equivalent to those of conventionally electrodeposited PB on MWCNTs/Au and Au electrodes, demonstrating that the mass transfer of K+ and H2O2 inside our MWCNTs is comparable to those outside our MWCNTs at the low scan rates. Furthermore, the unoccupied outer surfaces of MWCNTs-PBin are conveniently exploited to bind 4-(1-pyrenyl) butyric acid through π–π stacking interaction and then to anchor glucose oxidase or lactate oxidase through the EDC/NHS chemistry. Thus, we have developed a novel cooperative biosensing mode by combining outer-surface biocatalyzed oxidation of substrate with interior PB-catalyzed reduction of enzymatically generated H2O2, which endows our biosensors with low detection potential (−0.1 V) and satisfactory sensitivity/selectivity.
    The Journal of Physical Chemistry C. 09/2012; 116(39):20908–20917.
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    ABSTRACT: We report on the thiol-ene chemistry guided preparation of novel thiolated polymeric nanocomposite films of abundant anionic carboxylic groups for electrostatic enrichment and sensitive electroanalysis of cationic dopamine (DA) in neutral solution. Briefly, the thiol-ene nucleophilic reaction of a carboxylated thiol with oxidized polypyrrole (PPy), which was electrosynthesized on an Au electrode in the presence of solution-dispersed acidified multiwalled carbon nanotubes (MWCNTs), produced an a PPy-thiol-MWCNTs/Au electrode, and the PPy can be electrochemically overoxidized (OPPy) to form an OPPy-thiol-MWCNTs/Au electrode. The carboxylic groups of the polymeric nanocomposite film originate from the acidified MWCNTs, PPy-tethered carboxylated thiol, and OPPy. The carboxylated thiols examined are mercaptosuccinic acid (MSA) and thioglycolic acid, with β-mercaptoethanol as a control. Electrochemical quartz crystal microbalance, scanning electron microscopy, Fourier transform infrared spectroscopy and ultraviolet-visible spectroscopy were used for film characterization and process monitoring. Under the optimized condition, the differential pulse voltammetry peak current of DA oxidation at OPPy-MSA-MWCNTs/Au electrode is linear with DA concentration from 1.00×10(-9) to 2.87×10(-6) mol L(-1), with a limit of detection of 0.4 nmol L(-1), good anti-interferent ability and stability.
    Biosensors & bioelectronics 04/2012; 36(1):154-60. · 5.43 Impact Factor
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    ABSTRACT: Enzyme immobilization is one of the key factors in constructing high-performance enzyme biosensors and biofuel cells (BFCs). Herein, we propose a new protocol for efficient immobilization of a glycoprotein enzyme based on the interaction of the 1, 2- or 1, 3-diols in the glycoprotein with a boronic acid functionalized monomer. Briefly, casting a mixture of glucose oxidase (GOx) and anilineboronic acid (ABA) followed by a NaAuCl(4) solution to an Au-plated Au electrode surface yielded a GOx-poly(ABA) (PABA)-gold nanoparticle (Au(nano)) bionanocomposite, and chitosan (CS) was then cast and air-dried. In the present protocol, the small-sized Au(nano) or Au subnanostructures can form near/on the enzyme molecule, which greatly promotes the electron transfer of enzymatic reaction and enhances the amperometric responses. The thus-prepared CS/GOx-PABA-Au(nano)/Au-plated Au electrode worked well in the first-/second generation biosensing modes and as a bioanode in a monopolar biofuel cell, with analytical or cell-power performance superior to those of most analogues hitherto reported.
    Biosensors & bioelectronics 10/2011; 31(1):357-62. · 5.43 Impact Factor
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    ABSTRACT: We report on the exploitation of metal-organic coordination polymers (MOCPs) as new and efficient matrixes to immobilize enzymes for amperometric biosensing of glucose or phenols. A ligand, 2,5-dimercapto-1,3,4-thiadiazole (DMcT), two metallic salts, NaAuCl(4) and Na(2)PtCl(6), and two enzymes, glucose oxidase (GOx) and tyrosinase, are used to demonstrate the novel concept. Briefly, one of the metallic salts is added into an aqueous suspension containing DMcT and one of the enzymes to trigger the metal-organic coordination reaction, and the yielded MOCPs-enzyme biocomposite (MEBC) is then cast-coated on an Au electrode for biosensing. The aqueous-phase coordination polymerization reactions of the metallic ions with DMcT are studied by visual inspection as well as some spectroscopic, microscopic, and electrochemical methods. The thus-prepared glucose and phenolic biosensors perform better in analytical performance (such as sensitivity and limit of detection) than those prepared by the conventional chemical and/or electrochemical polymerization methods and most of the reported analogous biosensors, as a result of the improved enzyme load/activity and mass-transfer efficiency after using the MOCPs materials with high adsorption/encapsulation capability and unique porous structure. For instance, the detection limit for catechol is as low as 0.2 nM here, being order(s) lower than those of most of the reported analogues. The enzyme electrode was also used to determine catachol in real samples with satisfactory results. The emerging MOCPs materials and the suggested aqueous-phase preparation strategy may find wide applications in the fields of bioanalysis, biocatalysis, and environmental monitoring.
    Analytical Chemistry 08/2011; 83(17):6511-7. · 5.70 Impact Factor
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    ABSTRACT: Three-dimensional porous platinum (Ptpor) films are prepared based on Pt electrodeposition on polyaniline (PANI) modified electrodes followed by selective dissolution of PANI with HNO3. Electrochemical quartz crystal microbalance data suggest that the PANI-H2PtCl6 interaction involves redox and coordination reactions, depending on the working potential. The Ptpor shows better electrocatalytic performance than the Pt/PANI and conventionally electrodeposited Pt. The Ptpor modified glassy carbon electrode (GCE) can electrocatalyze the oxidation of H2O2 with a sensitivity of 414 µA cm−2 mM−1 and a detection limit of 9 nM, and the chitosan-glucose oxidase/Ptpor/GCE can sense glucose with a sensitivity of 93.4 µA cm−2 mM−1.
    Electroanalysis 05/2011; 23(7):1681 - 1690. · 2.82 Impact Factor
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    ABSTRACT: A simple and efficient post-labeling strategy based on dye-induced peeling of the aptamer molecules off single-walled carbon nanotubes was developed for electrochemical aptasensing of thrombin with a detection limit down to 3 pM.
    Chemical Communications 03/2011; 47(9):2637-9. · 6.38 Impact Factor
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    ABSTRACT: We report on the electrodeposition of a 3-aminopropyltriethoxysilane-chitosan (APTES–CS) hybrid gel film for in situ immobilization of glucose oxidase (GOx) on an Au or platinized Au (Ptnano/Au) electrode for biosensing of glucose. Controllable electroreduction of p-benzoquinone is used to lift the electrode-surface pH for the GOx–APTES–CS codeposition, which was monitored by an electrochemical quartz crystal microbalance. The fabrication procedures of the biosensor and the parameters influencing the biosensing performance were optimized. The prepared porous GOx–APTES–CS/Ptnano/Au and GOx–APTES–CS/Au electrodes can be used to detect the enzymatically generated H2O2 at 0.5 and 0.7V vs SCE, respectively. The enzyme electrodes exhibited linear responses to glucose concentration from 0.2μM to 8.2mM (R=0.998, at Ptnano/Au substrate) and from 0.2μM to 5.5mM (R=0.998, at Au substrate), with current sensitivities of 69.5 (Ptnano/Au) and 65 (Au) μAmM−1cm−2, respectively, and a detection limit of 0.2μM (S/N=3) was achieved for each electrode. The response time was less than 5 (Ptnano/Au) or 8 (Au) s. It is striking that the enzyme electrodes remained their initial response sensitivity after storage for 5 (Au) and >6 (Ptnano/Au) months in 0.10M PBS (pH 7.0) at 4°C.
    Sensors and Actuators B-chemical - SENSOR ACTUATOR B-CHEM. 01/2011; 157(1):282-289.
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    ABSTRACT: Rapid oxidation of dopamine (DA) or L-noradrenaline (NA) by K(3)Fe(CN)(6) yields poly(DA) (PDA(C)) or poly(NA) (PNA(C)) with glucose oxidase (GOx) effectively entrapped, and such an enzyme-entrapped catecholamine polymer is cast on an Au electrode followed by chitosan (CS) strengthening for biosensing and fabrication of a biofuel cell (BFC). The optimized glucose biosensor of CS/PDA(C)-GOx/Au displays an extremely high sensitivity up to 135 μA mM(-1) cm(-2), a very low limit of detection of 0.07 μM, a response time of <3 s, good suppression of interferents, striking thermostability (lifetime of 3 weeks at 60°C and over 2 months at 30°C), and high resistance to urea denaturation. The biosensor also works well in the second generation biosensing mode with p-benzoquinone (BQ) or ferrocene monocarboxylic acid (Fc) as an artificial mediator, with greatly broadened linear detection ranges (2.0 μM-48.0 mM for BQ and 2.0 μM-16.0 mM for Fc) and up to mA cm(-2)-scale glucose-saturated current density. The good permeability of artificial mediators across the enzyme film enables the quantification of the surface concentration of immobilized GOx on the basis of a reported kinetic model, and UV-Vis spectrophotometry is used to measure the enzymatic activity, revealing high enzymatic activity/load at CS/PDA(C)-GOx/Au. A BFC is also successfully fabricated with a bioanode of CS/PDA(C)-GOx/Au in phosphate buffer solution containing 100 mM glucose and 4.0 mM BQ and a carbon cathode in Nafion-membrane-isolated acidic KMnO(4), and its maximum power density of 1.62 mW cm(-2) is superior to those of most BFC hitherto reported.
    Biosensors & bioelectronics 10/2010; 26(5):2311-6. · 5.43 Impact Factor
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    ABSTRACT: We report on the aqueous preparation of novel polymeric bionanocomposites (PBNCs) with polydopamine (PDA) as an efficient matrix to support antibody and uniformly dispersed abundant Pt nanoparticles (PtNPs) for high performance sandwich-type amperometric immunoassay. We prepare three kinds of PBNCs (PBNCs 1, 2, and 3) via chemical polymerization synthesis (1) and further adsorption (2) or glutaldehyde (GA) covalent crosslinking (3) of antibody. Transmission electron microscopy, atomic force microscopy, and quartz crystal microbalance are used to characterize the PBNCs. The results show that PDA is an excellent matrix to support antibody and PtNPs due to its high biocompatibility, adsorbability, and processibility, and the thus-prepared PBNCs are of high immuno-recognition efficiency and high catalytic activity toward H(2)O(2) reduction. Then, we examine the applicability of the prepared PBNCs for sandwich-type amperometric immunosensing using a model immuno-pair of human immunoglobulin G (hIgG) and anti-hIgG, and obtain the signal by detecting the electro-reduction of H(2)O(2) catalyzed by the PtNPs label. The constructed immunosensors using PBNCs 1, 2 and 3 exhibit detection limits of 0.068, 0.037, and 0.018 ng mL(-1), respectively, being competitive with or better than the reported analogues. Our immunosensors also present good reproducibility, stability, regeneration ability, specificity, and satisfactory feasibility for target assay in clinical human serum samples. The suggested protocol for the preparation of PBNCs with high signal-transduction ability is expected to find wide bioassay applications.
    Biosensors & bioelectronics 03/2010; 25(7):1699-704. · 5.43 Impact Factor