Fei Fei Zhang

Graphene Modified Molecular Imprinted Electrochemical Sensor for Specific Recognition of Bovine Serum Albumin

A simple and efficient molecularly imprinted sensor (MIPs/GR/GCE) was firstly prepared by electropolymerization of pyrrole in the presence of bovine serum albumin (BSA) in an aqueous solution based on a graphene modified glassy carbon electrode for the selective recognition of bovine serum albumin. The prepared sensor was characterized by differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS), in which [Fe(CN)6]3−/4− was used as an electrochemical active probe. The results showed a wide linear range from 1.0 × 10-3 to 1.0 × 10-9 g/mL. And the imprinted biosensor indicated excellent selectivity and high sensitivity.

Synthesis and Characterization of ZrO2/Graphene Nanocomposite Materials

Zirconia/graphene (ZrO2/graphene) nanocomposite has been successfully synthesized by a simple method. The as-prepared nanocomposite was characterized using transmission electron microscopy (TEM), FT-IR spectroscopy, power X-ray diffraction (XRD) and nitrogen adsorption-desorption. It was found that tetragonal ZrO2 was uniformly deposited on graphene, which resulted in the formation of two-dimensional nanocomposite, it showed a high surface area of 165 m2/g.

Selective Determination of Dopamine at Poly Sulfosalicylic Acid/Graphene Modified Electrode with Composite Properties of Biochemical Materials

A new type of poly (sulfosalicylic acid)/graphene modified electrode (PSA/GH/GCE) was fabricated by dispensing graphene (GH) on glassy carbon electrode (GCE) and then electro-polymerized sulfosalicylic acid onto GH/GCE with cyclic voltammtry method. It can be used with composite properties of biochemical materials for highly selective and sensitive detection of dopamine (DA) even in the presence of mass ascorbic acid (AA). The linear response range for DA was 70 nM to 700 μM, and the detection limit was 20 nM (S/N = 3).

One Step Synthesis and Characterization of Zirconia-Graphene Composites

Zirconia-graphene composite (ZrO2-G) has been successfully synthesized via decomposition of ZrOCl2•6H2O in a water-isopropanol system with dispersed graphene oxide (GO) utilizing Na2S as a precursor could enable the occurrence of the deposition of Zr4+ and the deoxygenation of GO at the same time. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques were used to characterize the samples. It was found that graphene were fully coated with ZrO2, and the ZrO2 existing in tetragonal phase, which resulted in the formation of two-dimensional composite.

Self-Assembled Hybrid Films of Graphene/Carbon Nanotube Modified Electrode for Sensitive and Selective Determination of Rutin

Abstract: Graphene/Carbon Nanotube hybrid films modified glassy carbon electrode (GN-CNT/GC) was fabricated as electrochemical sensor for the sensitive and rapid determination of rutin. The electrochemical behaviors of rutin at the GN-CNT/GC have been investigated. Rutin can generate a pair of well-defined redox peaks at the GN-CNT/GC located at 0.450 V (Epa) and 0.409 V (Epc). Compared with graphene modified glassy carbon electrode (GN/GC) and carbon nanotube modified glassy carbon electrode (CNT/GC), GN-CNT/GC showed a higher catalytic activity toward rutin. This result indicates that the GN-CNT hybrid films as a modifier strengthens the adsorption of rutin. Cyclic voltammetry (CV), different pulse voltammetry (DPV) and transmission electron microscopy (TEM) were employed to characterize the electrochemical sensor and hybrid films. Under the optimal conditions, the oxidation peak current is linear to the rutin concentration over the range of 2.0×10-7-6.0×10-5 M and the detection limits were 1.0×10-7 M.

A Novel Silver-Doped Poly(p-aminobenzene sulfonic acid) Modified Glassy Carbon Electrode for Analysis of H2O2

A novel silver-doped poly (p-aminobenzene sulfonic acid) modified electrode was fabricated, of which the electrochemical behaviors were studied with H2O2 as a probe. In pH 7.0 PBS, a sensitive reductive peak of H2O2 was observed. The modified electrode is of potential in practice for analysis of H2O2 in samples such as milk.

Preparation of Molecularly Imprinted Polypyrrole and Carbon Nanotubes Film Modified Electrode for Dopamine Recognition

A novel film of overoxidized polypyrrole and carboxylic multi-walled carbon nanotubes (c-MWNTs) was fabricated with molecular imprinted technique for dopamine by a direct and facile electropolymerization method. The resulting modified electrode surface was characterized with electrochemical impedance spectroscopy and Fourier transform infrared spectroscopy. The results demonstrated that the modified electrode not only possessed a good sensitivity but also exhibited a high selectivity toward DA which making anodic potential difference of DA and AA is 318 mV in DPV. Under the optimum conditions, the linear range of the dopamine biosensor ranges from 5.0×10−8 to 6.0×10−6 mol/L with a detection limit of 5.0×10−9 mol/L

A Stripping Voltammetric Method for Iodine Ion at Chitosan Incorporating Carbon Nanotubes Modified Electrode

A novel chitosan incorporating carbon nanotubes coated electrode was constructed and applied to the differential pulse voltammetric (DPV) anodic stripping voltammetric characteristics of iodine ion. The modified electrodes, exhibiting both of unique properties of CNT and chitosan, has excellent electrocatalytic effect of I-. The sensitive detection of iodine ion has been further improved. A linear calibration curve was obtained for 1×10-6 mol/L to 1×10-3 mol/L in 0.1 mol/L KH2PO4 buffer (pH = 4.0) with correlation coefficient of 0.998 and detection limit of 0.2 μmol/L. The practical analytical application was illustrated by a measurement of iodine ion in salt.

Nonenzymatic Electrochemical Detection of Glucose Using Well-Distributed Gold Nanoparticles on Graphene/Carbon Nanotube Nanohybrids

A nonenzymatic electrochemical sensor was fabricated for glucose detection based on gold nanoparticles graphene/carbon nanotube nanohybrids (AuNPs-GH/CNT), which were synthesized through in situ reduction procedure. Cyclic voltammetry (CV) and amperometry were used to evaluate the catalytic activity of the AuNPs-GH/CNT-Nafion modified electrode towards glucose. It was founded that AuNPs-GH/CNT-Nafion modified electrode showed remarkable enhanced electrocatalytic activity towards the oxidation of glucose under optimized conditions. The sensors exhibited linear behavior in the concentration range from 5 μM to 1 mM for the quantification of glucose with a limit of detection of 1.5 μM.

Ultrasensitive Determination of Rutin on Ag Nanoparticles- Poly(p-aminobenzene sulfonic acid)/Graphene Modified Glassy Carbon Electrode

The Ag nanoparticles-Poly(p-aminobenzene sulfonic acid)/graphene modified glassy carbon electrode (AgNPs-PABSA/GR/GCE) was fabricated by electrodepositon of AgNPs-PABSA onto graphene modified glassy carbon electrode (GR/GCE). The reported method was simple and fast. Combining the advantages of GR (high surface area and good conductivity), AgNPs (excellent electronic conductivities) and PABSA (the ability to interact with many components through hydrophobic or π–π electronic interaction), the AgNPs-PABSA/GR modified electrode effectively improved the sensitivity for the determination of rutin.