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A Multichannel Automated Amperometric Test System for Glucose Monitoring Biosensor Quality Control Testing
Author(s) -
Chen Qiang,
Kersten Brian,
Li Jay,
Wu Christine,
Jagasia Priya,
Ewing Al
Publication year - 2001
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/1521-4109(200101)13:1<61::aid-elan61>3.0.co;2-h
Subject(s) - potentiostat , biosensor , amperometry , detection limit , sensitivity (control systems) , software , response time , computer science , chromatography , chemistry , materials science , nanotechnology , engineering , electronic engineering , electrode , electrochemistry , programming language , computer graphics (images)
Abstract An automated system has been designed for routine amperometric testing of biosensor components for Cygnus Inc.'s GlucoWatch glucose monitoring device. Sensitivity of biosensors is measured as the amperometric response to hydrogen peroxide standards, across development lots, for lot release, and for stability testing. The automated system consists of five principal components: 1) a Gilson Model 223 liquid handling system with Model 402 syringe pump; 2) flow cells designed to hold biosensors; 3) programmable calibrated potentiostats; 4) valves, solenoids, and relays to direct flow and initiate potentiostats; and 5) software to control the liquid handling and potentiostat programming, and software for data acquisition. The system sequence consists of downloading potentiostat voltage‐time programs, preconditioning the sensors under test, and then directing 0, 1, 5, and 10 µM H 2 O 2 to the biosensors. The potentiostat is started after each injection, and the resulting current is measured at selected intervals. Sensor current is measured over 5 minutes, and the sensor response is determined using the observed current at selected intervals. Sensor sensitivity is measured as the slope of sensor response versus H 2 O 2 concentration. The limit of quantitation of this automated method is 0.5 µM H 2 O 2 and the analytical precision is less than 10 % RSD at 5 µM H 2 O 2 . Peroxide decline in standards is limited to less than 5 % over 8 h at room temperature, and less than 2 % over the typical analysis time of 4 h. This system provides a reliable, precise and easy procedure for multichannel amperometric biosensor testing.