| 1. |
- Alpeeva, IS, et al.
(author)
-
Bi-enzyme alcohol biosensors based on genetically engineered alcohol oxidase and different peroxidases
- 2005
-
In: Microchimica Acta. - : Springer Science and Business Media LLC. - 1436-5073 .- 0026-3672. ; 152:1-2, s. 21-27
-
Journal article (peer-reviewed)abstract
- We report on the development of a bi-layer bi-enzyme biosensor architecture using different peroxidases and alcohol oxidase from Hansenula polymorpha C-105 as biological recognition elements. The sensor architecture comprises a first layer containing either horseradish peroxidase or royal palm tree peroxidase crosslinked with an Osmium complex-modified redox hydrogel. On top, a second layer was formed by electrochemically induced precipitation of a cathodic electrodeposition paint simultaneously entrapping alcohol oxidase isolated from a genetically modified strain of Hansenula polymorpha C-105. The sensor architecture was optimized with respect to effective electron transfer and stability of the enzyme. The main characteristics of the biosensors are an apparent maximal current I-max(app) of 572-940 nA, an apparent Michaelis constant K-M(app) of 9.5 mM, a sensitivity of 60-98 nA mM(-1) and an improved operational stability represented by a deactivation constant of 1.5-2.0 x 10(-4) min(-1).
|
|
| 2. |
- Alpeeva, IS, et al.
(author)
-
Palm tree peroxidase-based biosensor with unique characteristics for hydrogen peroxide monitoring
- 2005
-
In: Biosensors & Bioelectronics. - : Elsevier BV. - 1873-4235 .- 0956-5663. ; 21:5, s. 742-748
-
Journal article (peer-reviewed)abstract
- Three amperometric enzyme electrodes have been constructed by adsorbing anionic royal palm tree peroxidase (RPTP), anionic sweet potato peroxidase (SPP), or cationic horseradish peroxidase (HRP-C) on spectroscopic graphite electrodes. The resulting H2O2-sensitive biosensors were characterized both in a flow injection system and in batch mode to evaluate their main bioelectrochemical parameters, such as pH dependency,I-max, K-M(app), detection limit, linear range, operational and storage stability. The obtained results showed a distinctly different behavior for the plant peroxidase electrodes, demonstrating uniquely superior characteristics of the RPTP-based sensors. The broader linear range observed for the RPTP-based biosensor is explained by a high stability of this enzyme in presence of H2O2. The higher storage and operational stability of RPTP-based biosensor as well as its capability to measure hydrogen peroxide under acidic conditions connect with an extremely high thermal and pH-stability of RPTP.
|
|
