Effect of gold nanoparticles on the electrocatalytic reduction of oxygen by silica encapsulated cobalt phthalocyanine

Methylene blue incorporated mesoporous silica microsphere based sensing scaffold for the selective voltammetric determination of riboflavin

Methylene blue incorporated sulfonic acid functionalized mesoporous silica microspheres is synthesized and utilized as effective sensing scaffold for electrochemical determination of nanomolar levels of riboflavin.

The influence of gold nanoparticles on the electroactivity of nickel tetrasulfonated phthalocyanine

We report on the electrodeposition of gold nanoparticles ( AuNPs ) on a glassy carbon electrode (GCE) followed by deposition of nickel tetrasulfonated phthalocyanine ( NiTSPc ) film by electropolymerization (poly- NiTSPc -GCE) to form Poly- NiTSPc / AuNPs -GCE. The presence of the gold nanoparticles caused a lowering of the anodic and cathodic peak separation (ΔE p ) of ferricyanide from 126 mV on poly- NiTSPc to 110 mV on poly- NiTSPc / AuNPs . The electrooxidation of nitrite improved on modified electrodes compared to GCE, with the latter giving E p = 0.78 V and the modified electrodes gave E p = 0.62 V or 0.61 V. Poly- NiTSPc / AuNPs -GCE had higher currents compared to poly- NiTSPc -GCE. This indicates the enhancement effect caused by the AuNPs . Electrochemical impedance spectroscopy and chronoamperometric studies also showed that poly- NiTSPc / AuNPs -GCE was a better electrocatalyst than poly- NiTSPc -GCE or AuNPs -GCE.

New voltammetric strategy for simultaneous determination of N-acetylcysteine and folic acid using a carbon nanotube modified glassy carbon electrode

A novel 1-benzyl-4-ferrocenyl-1H-[1,2,3]-triazole (BFT)/carbon nanotube modified glassy carbon electrode (BFT-CNT-GCE) was prepared for the simultaneous determination of N-acetylcysteine (NAC) and folic acid (FA). Cyclic voltammetry (CV), chronoamperometry (CHA), and square wave voltammetry (SWV) methods were used to investigate the modified electrode for the electrocatalytic oxidation of NAC and FA in aqueous solutions. The separation of the oxidation peak potentials for NAC-FA was about 280 mV. The calibration curve obtained for NAC was in the range of 0.1-600.0 μM. The detection limit (S/N=3) was 62.0±2.0 nM for NAC. The diffusion coefficient and the catalytic rate constant for the oxidation of NAC at the modified electrode were calculated as (3.5±0.2)×10(-5) cm(2) s(-1) and (9.85±0.4)×10(-4) M(-1) s(-1), respectively. The method was employed for the determination of NAC and FA in some real samples.