Reactivities of Organic-Phase Biosensors. 1. Enhancement of the Sensitivity and Stability of Amperometric Peroxidase Biosensors Using Chemically Modified Enzymes
| Autor: | Malcolm R. Smyth,† and, Enda Miland, Emmanuel I. Iwuoha, Ingrid Leister, Ciarán Ó Fágáin |
|---|---|
| Rok vydání: | 1997 |
| Předmět: | |
| Zdroj: | Analytical Chemistry. 69:1674-1681 |
| ISSN: | 1520-6882 0003-2700 |
| Popis: | Amperometric organic- and aqueous-phase peroxide biosensors were prepared with native and N-hydroxysuccinimide ester (NHS)-modified horseradish peroxidase (HRP). The e-amino functions of the free lysine residues of HRP were selectively modified with homobifunctional suberic acid bis(N-hydroxysuccinimide ester) (SA-NHS) or ethylene glycol bis(succinic acid N-hydroxysuccinimide ester) (EG-NHS). The biosensors were based on electrostatic complexation of the HRP variants with an osmium bis(bipyridyl)poly(4-vinylpyridine) polymer. The enzyme electrodes were operated in both aqueous (0.1 M phosphate buffer, pH 7.0) and organic (90% CH3CN) phases, for the detection of hydrogen peroxide and methyl isothiocyanate. Kinetic analysis of the steady-state amperometry data showed that chemical modification of HRP brought up to a ∼5-fold enhancement of the biosensor sensitivity for H2O2 and an improvement in both sensor stability and organotolerance. Also, NHS modification of HRP results in a 3-fold extension of the rang... |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|