Hankil Boo

Nonenzymatic continuous glucose monitoring in human whole blood using electrified nanoporous Pt.

This paper describes the first devised method for the nonenzymatic and electrochemical glucose monitoring in 100% human whole blood and serum. The nanoporous Pt electrode allows for the selective amplification of glucose oxidation in the presence of electroactive interfering species without the need for enzymatic reaction. The outer membrane was particularly optimized to allow glucose molecules to be electrochemically detected against the numerous constituents of human blood. The proposed sensor provided reproducible amperometric responses to glucose in human serum and whole blood. Its sensitivity was maintained for at least 7h under constantly electrified conditions, and continued to work properly after 30 days of storage in human whole blood and serum. Unlike the enzyme-based glucose sensors, it was found to be minimally affected by thermal fluctuation, so as to remain successful even after steam sterilization at high temperature (134 °C) and pressure (0.22 Mpa). The unprecedented long-term stability and sterilization compatibility observed herein suggest a promising alternative to conventional enzymatic glucose sensors for many analytical and clinical applications, particularly for continuous glucose monitoring devices designed to potentially lead to a closed-loop artificial pancreas by combining them with an insulin pump.

Determination of Fluoroquinolone Antibacterial Agents by Square Wave Adsorptive Stripping Voltammetry

Electrochemical behavior of fluoroquinolone antibacterial agents on carbon paste electrode (CPE) were investigated by cyclic voltammetry and square wave adsorptive stripping voltammetry. The fluoroquinolone antibacterial agents tested in this study were Enrofloxacin (ENR), Norfloxacin (NOR), Ciprofloxacin (CIP), Ofloxacin (OFL) and Levofloxacin (LEV). In acetate buffer at pH 4.5, the oxidation peak potentials of the fluoroquinolone antibacterial agents of ENR, NOR, CIP, OFL, and LEV were 0.952 V, 1.052 V, 1.055 V, 0.983 V, and 0.990 V (vs. Ag/AgCl), respectively. And their oxidation peak currents from square wave adsorptive stripping voltammograms are proportional to the concentration of each antibacterial agent over the range from 0.2 µM to 1 µM.