Fabrication of microband glucose biosensors using a screen-printing water-based carbon ink and their application in serum analysis.
Microband glucose biosensors were fabricated by screen-printing a water-based carbon ink formulation containing cobalt phthalocyanine redox mediator and glucose oxidase (GOD) enzyme, then insulating and sectioning through the thick (20mum) film to expose a 3mm-long working electrode edge. The performance of these biosensors for glucose analysis was investigated at 25 degrees C. Voltammetry in glucose-containing buffer solutions established that an operating potential of +0.4V vs. Ag/AgCl was suitable for analysis under both stirring and quiescent conditions. The influence of pH on biosensor performance was established and an operational pH of 8.0 was selected. Steady-state responses were obtained under quiescent conditions, suggesting a mixed mechanism predominated by radial diffusion, indicative of microelectrode behaviour. Calibration studies obtained with these biosensors showed steady-state currents that were linearly dependent on glucose concentration from the limit of detection (0.27mM) up to 2.0mM, with a precision for replicate biosensors of 6.2-10.7%. When applied to the determination of glucose in human serum, the concentration compared favourably to that determined by a spectroscopic method. These results have demonstrated a simple means of fabricating biosensors for glucose measurement and determination in situations where low-current real-time monitoring under quiescent conditions would be desirable.
Pemberton
R M
RM
Centre for Analytical, Materials and Sensors Science, Faculty of Health and Life Sciences, University of the West of England, Bristol BS16 1QY, UK.
Pittson
R
R
Biddle
N
N
Hart
J P
JP
D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D001774:Blood Chemical Analysis / Q000295:instrumentation*; D001786:Blood Glucose / Q000032:analysis*; D002244:Carbon / Q000737:chemistry*; D004563:Electrochemistry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007281:Ink; D008839:Microelectrodes; D008904:Miniaturization; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014867:Water / Q000737:chemistry
D001786:Blood Glucose; D014867:Water; D002244:Carbon