In vitro and in vivo performance and lifetime of perfluorinated ionomer-coated glucose sensors after high-temperature curing.
In this paper we report that curing at 120 degrees C can be used to improve the in vivo durability of a miniaturized glucose sensor with an outer coating of the Dupont perfluorinated ionomer, Nafion. Sensors based on glucose oxidase trapped in an albumin/glutaraldehyde matrix were able to withstand curing at 120 degrees C without noticeable change in electrode sensitivity (+/- 22% SD). Curing above 120 degrees C caused a gradual decline in sensitivity, with no sensitivity seen at 170 degrees C. Curing Nafion at 120 degrees C eliminated ascorbic acid and urea interferences and improved selectivity for glucose against uric acid and acetaminophen, compared to room temperature-cured Nafion coatings. The Nafion film reduced O2 demand by the sensor, so the signal was O2 independent across a partial pressure range of 8-140 mmHg. Several of the fully assembled, heat-cured, needle-type glucose sensors remained functional for at least 10 days after subcutaneous implantation in dogs, without degradation of their sensitivity (average 3 nA/mM in vivo at 37 degrees C and 6 nA/mM in vitro at 37 degrees C).
Moussy
F
F
Department of Chemistry, University of Alberta, Edmonton, Canada.
Jakeway
S
S
Harrison
D J
DJ
Rajotte
R V
RV
D000818:Animals; D015374:Biosensing Techniques / Q000592:standards*; D004285:Dogs; D004800:Enzymes, Immobilized / Q000378:metabolism; D005465:Fluorocarbon Polymers / Q000737:chemistry*; D005947:Glucose / Q000737:chemistry / Q000378:metabolism*; D005949:Glucose Oxidase / Q000378:metabolism; D006358:Hot Temperature; D010539:Permeability; D010655:Phenylenediamines / Q000737:chemistry; D011108:Polymers
D004800:Enzymes, Immobilized; D005465:Fluorocarbon Polymers; D010655:Phenylenediamines; D011108:Polymers; C040402:perfluorosulfonic acid; C034193:1,2-diaminobenzene; D005949:Glucose Oxidase; D005947:Glucose