Potentially-implantable, ferrocene-mediated glucose sensor.
We describe the construction and in vitro testing of a new potentially-implantable amperometric glucose sensor which is based on mediated electron transfer between immobilized glucose oxidase and a graphite base electrode. Under potentiostatic control, entrapped 1,1'-dimethylferrocene acts as an alternative electron acceptor to oxygen and provides a sensing strategy which is relatively unaffected by possible fluctuations in in vivo oxygen tension. Simple 1 mm wide electrodes with a polyurethane membrane gave linear current responses to at least 20 mmol/l glucose with a mean response time of 68 s. An acceptable proportion (17%) of electrodes had low or zero drift over 17 h at 37 degrees C. With plasma samples from diabetic and non-diabetic subjects, glucose concentrations measured by the sensor were significantly correlated with values obtained by a reference laboratory glucose analyser but were proportionally lower. Extension of this study to in vivo testing and further miniaturization of electrodes is justified.
D001786:Blood Glucose / Q000032:analysis*; D004566:Electrodes; D004800:Enzymes, Immobilized; D005296:Ferrous Compounds; D005949:Glucose Oxidase; D006108:Graphite; D006801:Humans; D000075163:Metallocenes; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D009942:Organometallic Compounds; D019736:Prostheses and Implants
D001786:Blood Glucose; D004800:Enzymes, Immobilized; D005296:Ferrous Compounds; D000075163:Metallocenes; D009942:Organometallic Compounds; D006108:Graphite; D005949:Glucose Oxidase; C004998:ferrocene