Simultaneous determination of norepinephrine, acetaminophen and tyrosine by differential pulse voltammetry using Au-nanoparticles/poly(2-amino-2-hydroxymethyl-propane-1,3-diol) film modified glassy carbon electrode.

A novel Au-nanoparticles/poly-(2-amino-2-hydroxymethyl-propane-1,3-diol) film modified glassy carbon electrode (AuNPs/poly(trisamine)/GCE) was constructed for the simultaneous determination of norepinephrine (NE), acetaminophen (AC) and L-tyrosine (Tyr) by differential pulse voltammetry. Electrochemical impedance spectroscopy and scanning electron microscopy indicate that the trisamine film was successfully polymerized on the surface of GCE and the film efficiently decreased the charge transfer resistance value of electrode and improved the electron transfer kinetic between analytes and electrode. The separation of the oxidation peak potentials for NE-AC and AC-Tyr were about 160 mV and 240 mV, respectively. The calibration curves for NE, AC and Tyr were obtained in the range of 1.3-230.1 μmol L(-1), 1.90-188.0 μmol L(-1), and 3.9-61.8 μmol L(-1), respectively. The detection limits (S/N=3) were 0.07 μmol L(-1), 0.1 μmol L(-1) and 0.9 μmol L(-1), for NE, AC and Tyr, respectively. The diffusion coefficient and the catalytic rate constant for the oxidation reaction of NE at AuNPs/poly(trisamine)/GCE were calculated as 1.55 (±0.2)×10(-6) cm2 s(-1) and 2.28 (±0.17)×10(3) mol(-1) L s(-1), respectively. Finally, AuNPs/poly(trisamine)/GCE was satisfactorily used for the determination of NE, AC, and Tyr in pharmaceutical and biological samples.

Taei M ，Ramazani G 《-》

Simultaneous determination of L-cysteine and L-tyrosine using Au-nanoparticles/poly-eriochrome black T film modified glassy carbon electrode.

A novel Au-nanoparticles/poly-eriochrome black T film modified glassy carbon electrode (AuNPs/PEBT/GCE) was constructed for the simultaneous determination of l-cysteine (L-Cys) and l-tyrosine (L-Tyr) by differential pulse voltammetry. Fourier transform infrared spectra and electrochemical impedance spectroscopy indicate that the PEBT film was successfully polymerized on the surface of GCE and the film efficiently decreased the charge transfer resistance value of electrode and improved the electron transfer kinetic between analytes and electrode. The scanning electron microscope image shows that the immobilized AuNPs were spherical in shape and enhanced the electrical conductivity of PEBT film. In addition, PEBT film increased the oxidation currents of analytes four times when compared to bare GCE, and the AuNPs separated the oxidation potentials of L-Cys and L-Tyr by 488 mV while bare GCE failed to resolve them. The amperometry results exhibit that the electrocatalytic currents increased linearly with L-Cys concentrations in the range 0.05-100 μM (r=0.9981), and the detection limits of L-Cys and L-Tyr were 8 nM and 10 nM (S/N=3), respectively. With high sensitivity and selectivity, the proposed electrochemical sensor provides a simple method for simultaneous determination of L-Cys and L-Tyr.

Liu X ，Luo L ，Ding Y ，Kang Z ，Ye D ... -  《-》

Simultaneous determination of cysteine, uric acid and tyrosine using Au-nanoparticles/poly(E)-4-(p-tolyldiazenyl)benzene-1,2,3-triol film modified glassy carbon electrode.

A novel Au nanoparticles/poly(E)-4-(p-tolyldiazenyl)benzene-1,2,3-triol (AuNPs/PTAT) film modified glassy carbon electrode (AuNPs/PTAT/GCE) was fabricated for the simultaneous determination of three antioxidants named, cysteine (Cys), uric acid (UA) and tyrosine (Tyr). The bare glassy carbon electrode (GCE) fails to separate the oxidation peak potentials of these molecules, while PTAT film modified electrode can resolve them. Electrochemical impedance spectroscopy (EIS) study indicates that the charge transfer resistance of bare electrode increased as (E)-4-(p-tolyldiazenyl)benzene-1,2,3-triol was electropolymerized at the bare electrode. Furthermore, EIS exhibits enhancement of electron transfer kinetics between analytes and electrode after electrodeposition of Au nanoparticles. Differential pulse voltammetry results show that the electrocatalytic current increases linearly in the ranges of 2-540μmolL(-1) for Cys, 5-820μmolL(-1) for UA and 10-560μmolL(-1) for Tyr with detection limits (S/N=3) of 0.04μmolL(-1), 0.1μmolL(-1) and 2μmolL(-1) for Cys, UA and Tyr, respectively. The proposed method was successfully applied for simultaneous determination of Cys, UA and Tyr in human urine samples.

Taei M ，Hasanpour F ，Salavati H ，Banitaba SH ，Kazemi F ... -  《-》

Ultra-sensitive film sensor based on Al2O3-Au nanoparticles supported on PDDA-functionalized graphene for the determination of acetaminophen.

Li J ，Sun W ，Wang X ，Duan H ，Wang Y ，Sun Y ，Ding C ，Luo C ... -  《-》

Differential pulse voltammetric simultaneous determination of noradrenalin and acetaminophen using a hematoxylin biosensor.

Nasirizadeh N ，Zare HR 《-》