A new modified conducting carbon composite electrode as sensor for ascorbate and biosensor for glucose.
A new carbon-based conducting composite has been developed as electrochemical sensor and biosensor for the amperometric detection of ascorbate and glucose. Electrocatalytic oxidation of ascorbate has been done successfully at unmodified cellulose acetate-graphite composite electrodes, the sensor being highly sensitive, selective and with a low detection limit at 0.0 V vs. SCE and was successfully applied for ascorbate determination in commercial fruit juice samples. An interference free glucose biosensor has also been developed, based on the immobilisation of glucose oxidase by cross-linking with glutaraldehyde on poly (neutral red) modified composite electrodes. The biosensor exhibits a higher sensitivity of 31.5+/-1.7 microA cm(-2) mM(-1) than other carbon-composite-based glucose biosensors, a detection limit of 20.3 microM and a very short response time.
Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade de Coimbra, 3004-535 Coimbra, Portugal.
Madalina M
MM
Barsan
Christopher M A
CM
Brett
D001205:Ascorbic Acid / Q000032:analysis* / Q000737:chemistry; D001234:Aspergillus niger / Q000201:enzymology; D001628:Beverages / Q000032:analysis; D015374:Biosensing Techniques / Q000379:methods*; D002244:Carbon / Q000737:chemistry*; D002482:Cellulose / Q000031:analogs & derivatives / Q000737:chemistry; D004553:Electric Conductivity; D004563:Electrochemistry; D004566:Electrodes; D005947:Glucose / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D005949:Glucose Oxidase / Q000737:chemistry / Q000378:metabolism; D006108:Graphite / Q000737:chemistry; D009499:Neutral Red / Q000737:chemistry; D010084:Oxidation-Reduction; D011108:Polymers / Q000737:chemistry; D013379:Substrate Specificity
D011108:Polymers; D009499:Neutral Red; C005062:acetylcellulose; D002244:Carbon; D006108:Graphite; D002482:Cellulose; D005949:Glucose Oxidase; D005947:Glucose; D001205:Ascorbic Acid