We presented the colorimetric and electrochemical methods for determination of the dipeptidyl peptidase-IV (DPP-IV) activity and screening of its inhibitor using gold nanoparticle (AuNP) as the probe. In the colorimetric assay, the substrate peptide with a sequence of Arg-Pro-Arg induced the aggregation and color change of AuNPs, whereas cleavage of the peptide by DPP-IV prevented the aggregati...

Despite advances made in the field, rapid detection methods for the human pathogen Candida albicans are still missing. In this regard, bio-electrochemical systems including electrochemical sensors and biosensors satisfy the increasing demand for rapid, reliable, and direct microbial analyses. In this study, the bioelectrochemical characteristics of C. albicans were investigated for use in an an...

Electrochemical microsensors are ideal to measure substances with low concentration in complex environments. The primary excitatory neurotransmitter L-glutamate is present in many foods as a distinctive flavour (enhancer) with a wide concentration range. In comparison to other methods, electrochemical sensors allow the rapid, precise, cost-effective, online measurement without any sample treatm...

The electrochemistry of a poly(viny1ferrocene) (PVF) film of ca. 2100 8, was investigated in 1 M aqueous NaC104 solution with electrochemical and scanning microscopic techniques. The potential-step transients show well-defined maxima that a re very similar to those found for the electrochemical switching of electronically conductive polymers, e.g., polypyrrole and polyaniline. We explore here t...

The electrochemical oxidation of repaglinide has been carried out in Britton-Robinson buffer at carbon paste and glassy carbon electrodes. Repaglinide exhibits a well-defined irreversible oxidation peak over the entire pH range (2-11). Differential pulse voltammetry was used to determine repaglinide in pure form. The peak current varied linearly in the following ranges: 8.0 x 10(-7)-3.2 x 10(-6...

Hydrazine in water samples is determined by constant current chronopotentiometry in porous carbon electrodes. Hydrazine in alkaline solutions is oxidised to nitrogen in the pores of the electrode by constant current. Two types of electrodes made of reticulated vitreous carbon (RVC) were used, one fabricated from crushed RVC particles, the other with the original RVC material of 100 ppi porosity...

This laboratory seeks to quantitatively determine glucose concentration in common beverages. The method employed is enzyme catalyzed oxidation of glucose, quantified by chronoamperometry. With an inexpensive patterned electrode and low cost glucose oxidase enzyme, an electrochemical sensor is constructed to selectively measure glucose in complicated beverages which can present as analytically c...

A simple, accurate and sensitive voltammetric method for determination of Anagrelide (ANG) using β cyclodextrin modified carbon paste electrode (CDMCPE) is developed. CDMCPE exhibited significantly increased sensitivity and selectivity for ANG compared to Carbon paste electrode. Peak currents showed a linear response in the concentration range 1.8 × 10-9 to 1.6 × 10-6 M at CDMCPE. Limit of dete...

Antioxidant activity of a number of small (low molecular weight) natural compounds found in spices, condiments or drugs (gallic acid, sesamol, eugenol, thymol, carvacrol, vanillin, salicylaldehyde, limonene, geraniol, 4-hexylresorcinol, etc.) has been evaluated using electrochemical and DPPH• radical scavenging measurements. Structural analysis of the tested compound suggest a remarkable activi...