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Construction and characterization of novel electrochemical biosensors
Author
Miao, Yuqing
Supervisor
Tan, Swee Ngin
Abstract
This thesis is concerned with the development of amperometric enzyme electrodes based on chitosan and silica sol-gel immobilization techniques. Immobilization of enzymes onto electrode surfaces as applied to electrochemical biosensors has been a challenging and active research field among sensor technologists. Chitosan and novel silica sol-gel/chitosan derived carbon paste amperometric biosensors were developed.
Chapter 1 is an introduction to the biosensors, which are emerging as an important analytical tool widely applied in biochemical, pharmaceutical, and clinical fields. Amperometric enzyme electrode, which is a branch of biosensors, is discussed in detail with respect to the enzyme reaction kinetics, immobilization techniques and the performance of enzyme electrodes. It also covers the theoretical aspects involved in this thesis. Chitosan and silica sol-gel as immobilization support matrix, and electrochemical techniques including cyclic voltammetry and amperometry are discussed. The aims of the study are given at the end of the chapter.
In Chapter 2, a new enzymatic amperometric biosensor for the detection of hydrogen peroxide was developed via an easy and effective enzyme immobilization method using chitosan film cross-linked with glutaraldehyde. Horseradish peroxidase (HRP) was immobilized on the surface of a carbon paste electrode (CPE). Hexacyanoferrate (II) was present in the solution as a mediator. The fabrication procedure of the biosensor was optimized and the resulting biosensor exhibited a relatively fast response, wide linear range and good stability.
Chapter 3 describes the construction of a glucose biosensor with the following "sandwich" configuration: chitosan-ferrocene:GOX:chitosan using CPE as the basic electrode. The influence of operational parameters were explored in detail. Applicability of the biosensor was demonstrated in real samples.
In Chapter 4, a new type of silica sol-gel/chitosan hybrid material was used for the fabrication of an amperometric H2O2 biosensor. The composite consisting of sol-gel and natural polymer chitosan was used to immobilize HRP on a CPE electrode. The fabrication procedure was systematically optimized to improve the biosensor performance.
Chapter 1 is an introduction to the biosensors, which are emerging as an important analytical tool widely applied in biochemical, pharmaceutical, and clinical fields. Amperometric enzyme electrode, which is a branch of biosensors, is discussed in detail with respect to the enzyme reaction kinetics, immobilization techniques and the performance of enzyme electrodes. It also covers the theoretical aspects involved in this thesis. Chitosan and silica sol-gel as immobilization support matrix, and electrochemical techniques including cyclic voltammetry and amperometry are discussed. The aims of the study are given at the end of the chapter.
In Chapter 2, a new enzymatic amperometric biosensor for the detection of hydrogen peroxide was developed via an easy and effective enzyme immobilization method using chitosan film cross-linked with glutaraldehyde. Horseradish peroxidase (HRP) was immobilized on the surface of a carbon paste electrode (CPE). Hexacyanoferrate (II) was present in the solution as a mediator. The fabrication procedure of the biosensor was optimized and the resulting biosensor exhibited a relatively fast response, wide linear range and good stability.
Chapter 3 describes the construction of a glucose biosensor with the following "sandwich" configuration: chitosan-ferrocene:GOX:chitosan using CPE as the basic electrode. The influence of operational parameters were explored in detail. Applicability of the biosensor was demonstrated in real samples.
In Chapter 4, a new type of silica sol-gel/chitosan hybrid material was used for the fabrication of an amperometric H2O2 biosensor. The composite consisting of sol-gel and natural polymer chitosan was used to immobilize HRP on a CPE electrode. The fabrication procedure was systematically optimized to improve the biosensor performance.
Date Issued
2001
Call Number
R857.B54 Mia
Date Submitted
2001