An Integrated Glucose Sensor with an All-Solid-State Sodium Ion-Selective Electrode for a Minimally Invasive Glucose Monitoring System

Micromachines

Junko Kojima¹  Samiko Hosoya²  Chihiro Suminaka²  Nobuyasu Hori²  Toshiyuki Sato²  Kazunori Hoshino² 

[1] Central Research Laboratories, Sysmex Corporation, 4-4-4 Takatsukadai, Nishi-ku, Kobe, Hyogo 651-2271, Japan;

关键词: all-solid-state;    sodium ion sensor;    ion-selective electrode (ISE);    glucose sensor;    diabetes mellitus;    interstitial fluid;    minimally invasive glucose monitoring;   

DOI  :  10.3390/mi6070831

来源: mdpi

【 摘 要 】

We developed a minimally invasive glucose monitoring system that uses a microneedle to permeate the skin surface and a small hydrogel to accumulate interstitial fluid glucose. The measurement of glucose and sodium ion levels in the hydrogel is required for estimating glucose levels in blood; therefore, we developed a small, enzyme-fixed glucose sensor with a high-selectivity, all-solid-state, sodium ion-selective electrode (ISE) integrated into its design. The glucose sensor immobilized glucose oxidase showed a good correlation between the glucose levels in the hydrogels and the reference glucose levels (r > 0.99), and exhibited a good precision (coefficient of variation = 2.9%, 0.6 mg/dL). In the design of the sodium ISEs, we used the insertion material Na_0.33MnO₂ as the inner contact layer and DD16C5 exhibiting high Na⁺/K⁺ selectivity as the ionophore. The developed sodium ISE exhibited high selectivity ( = −2.8) and good potential stability. The sodium ISE could measure 0.4 mM (10^−3.4 M) sodium ion levels in the hydrogels containing 268 mM (10^−0.57 M) KCl. The small integrated sensor (ϕ < 10 mm) detected glucose and sodium ions in hydrogels simultaneously within 1 min, and it exhibited sufficient performance for use as a minimally invasive glucose monitoring system.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.