Amperometric enzyme electrodes for aerobic and anaerobic glucose monitoring prepared by glucose oxidase immobilized in mixed ferrocene-cobaltocenium dendrimers.
The enzyme glucose oxidase (GOx) has been immobilized electrostatically onto carbon and platinum electrodes modified with mixed ferrocene-cobaltocenium dendrimers. The ferrocene units have been used successfully as mediators between the GOx and the electrode under anaerobic conditions. In experiments carried out in the presence of oxygen, the cobaltocenium moieties act as electrocatalysts in the reduction of the oxygen in the solution, thus making possible the determination of the oxygen variation due to the enzymatic reaction, with high sensitivity. The current response of the electrode was determined by measuring steady-state current values obtained applying a constant potential. The effect of the substrate concentration, the dendrimer generation, the thickness of the dendrimer layer, interferences, and storage on the response of the sensors were investigated.
Alonso
Beatriz
B
Departamento de Química Inorgánica, Facultad de Ciencias, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain. beatriz.alonso@uam.es
Armada
Pilar García
PG
Losada
José
J
Cuadrado
Isabel
I
González
Blanca
B
Casado
Carmen M
CM
D000327:Adsorption; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D003035:Cobalt / Q000737:chemistry*; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis / Q000379:methods; D005296:Ferrous Compounds / Q000737:chemistry*; D005947:Glucose / Q000032:analysis* / Q000737:chemistry*; D005949:Glucose Oxidase / Q000737:chemistry*; D008567:Membranes, Artificial; D000075163:Metallocenes; D010100:Oxygen / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D004800:Enzymes, Immobilized; D005296:Ferrous Compounds; D008567:Membranes, Artificial; D000075163:Metallocenes; D011108:Polymers; D003035:Cobalt; D005949:Glucose Oxidase; D005947:Glucose; D010100:Oxygen; C004998:ferrocene