Osmium Redox Hydrogel Mediated Biosensor for Measurement of Low Concentration Glucose Extracted by Reverse Iontophoresis

Abstract

An osmium redox hydrogel mediated biosensor for continuous monitoring of glucose extracted from subcutaneous solution by reverse iontophoresis has been developed. For the measurement of low concentration glucose, osmiumpoly(vinylpyridine) wiring horseradish peroxidase was introduced to modify the smooth Au electrodes, and the developed glucose biosensor exhibited a high sensitivity of 11.45 nA mM À1 cm À2 and a low detection limit of 2 mM, as well as a high operational stability of more than 97% of its initial activity over a test period of 13.5 h in stirred glucose solution at low applied potential (À 0.1 V vs. Ag j AgCl), efficiently inhibiting the electroactive interferences. Permeability of the hydrogels was studied and a diffusion coefficient of 2.4 Â 10 À5 cm 2 /s for H 2 O 2 was obtained. In addition, the effects, such as temperature and the variation happening on Ag j AgCl counter electrode, on determination of glucose were also considered. The proof-of-feasibility of the biosensors for the monitoring of the glucose extracted from the subcutaneous solution was tested in vitro, and the responses of the sensors were analyzed. A linear response to current produced by extracted glucose in the concentration range of subcutaneous glucose from 1.0 to 12 mM was obtained with a correlation coefficient up to 0.989. These results testify the feasibility of the developed sensors for measuring the low concentration glucose and have significance for the development of noninvasive glucose monitoring system for the control of diabetes.

Small-volume solution current-time behavior study for application in reverse iontophoresis-based non-invasive blood glucose monitoring

“…Our previous work also confirmed the detection linear range of the investigated electrode was 2-600 μM, being competent in reverse iontophoresis system (about 5-100 μM drawn glucose) [34]. Figure 4 represents the current vs. time plots of the electrode in constructed small-volume glucose solution.…”

A cellulose/β-cyclodextrin nanofiber patch as a wearable epidermal glucose sensor

“…The proles are linear (R > 0.999), indicating that the sensor is activated along its entire geometric area and that the electrochemical reaction is under diffusion control. The diffusion coefficient for H 2 O 2 of the cellulose/b-CD/GOx NFs was approximately 9.0 Â 10 À5 cm 2 s À1 , which is higher than that obtained using an Os-HRP hydrogel 20 and a crosslinked PEO hydrogel. 21 For practical application of the biosensor, optimal permeability of the cellulose/b-CD/GOx NFs facilitates rapid accumulation of extracted glucose and is propitious to the measurement of the extracted glucose.…”

Organometallic polymers for electrode decoration in sensing applications

“…130 Like ferrocene-containing organometallic polymers, Oscontaining polymers can also form stable hydrogels in aqueous solution and provide excellent matrices for immobilizing enzymes on electrode surfaces. [137][138][139] When enzymes and mediators are co-immobilized in the lm, they are concentrated and closely connected which leads to strong bioelectrocatalytic activities. Much effort has been made to enhance the conductivity and performance of osmium-polymer-hydrogel-based biosensors.…”