Dual electrochemical determination of glucose and insulin using enzyme and ferrocene microcapsules
Journal
Biosensors and Bioelectronics
Journal Volume
22
Journal Issue
6
Pages
1147-1153
ISSN
0956-5663
Date Issued
2007-01-15
Author(s)
Viswanathan, S.
Abstract
Dual electrochemical determination of glucose and insulin has been developed, based on enzymatic reaction and immunoassay with utilization of ferrocene microcapsules, respectively. Glucose was determined through electrochemical oxidation of formed product, hydrogen peroxide, by the action of glucose oxidase (GOx). The layer-by-layer (LbL) films on the ferrocene microcrystal followed by anti-insulin antibody sensitization were employed for the biolabled ferrocene microcapsules production. The antibody sensitized ferrocene microcapsules worked as a probe in the proposed system. The microcapsules provided a higher signal generating molecule to antibody (S/P) ratio of 4.52 × 106 to 12.4 × 106. Microcapsules with different antibody loads (388-1070 antibody molecules per capsule) were subjected to a solid-phase immunoassay for the detection of insulin. The microcapsule having 1030 anti-insulin antibody molecules per capsule demonstrated good performance for insulin determination. The calibration curve for insulin had a linear range of 10-10 to 10-7 g mL-1 with R2 = 0.990, 3.9% R.S.D. The limit of detection for insulin was 10 pg mL-1 of 100 μL sample (equivalent to 10-12 g of insulin). The determination range for the glucose was 0.5 and 40 mM with R2 = 0.996 and 4.1% R.S.D.
Subjects
Amperometry
Glucose
Immunodetection
Insulin
Microcapsule
SDGs
Publisher
Elsevier B.V.
Type
journal article