Chemical Sensors and Biosensors E-Book

• Herausgeber: John Wiley & Sons
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 432

Veröffentlichungsjahr: 2012

Beschreibung

Technological needs for chemical, ionic and biological species detection are giving rise to continuous research and development in physico-chemistry and biology. The constant progress being made in the theoretical and technological aspects concerning studies and developments of chemical sensors, biosensors and biochips is presented in this book by different scientists and professors from different universities and constitutes an updating of the state of the art for chemical sensors, biosensors and biochips.

This book places a large emphasis on interaction between chemical and biological species, in a gaseous or liquid state, and details mineral and biological materials acting as sensitive elements. The role of electrical, electrochemical, piezoelectric and optical transducers in detection mechanisms are presented through their developments and from a performance point-of-view. Micro-reactors, nanotechnologies and flexible substrates, are considered in relation to their role in neural networks.

Leseprobe

Table of Contents

Preface

Chapter 1. Chemical and Biological Recognition

1.1. Gas molecule recognition

1.2. Ionic recognition

1.3. Biological recognition

1.4. Bibliography

Chapter 2. Adsorption Phenomena

2.1. The surface of a solid

2.2. Examining the adsorption phenomenon

2.3. Forces intervening between a gas molecule and the solid’s surface

2.4. Thermodynamic study of physical adsorption

2.5. Physical adsorption isotherms

2.6. Chemical adsorption isotherms

2.7. Bibliography

Chapter 3. Microcantilever Transduction

3.1. Introduction

3.2. Sensitive layers

3.3. Static mode

3.4. Dynamic mode

3.5. Example of measurement

3.6. Other uses for dynamic mode

3.7. Conclusion

3.8. Acknowledgments

3.9. Bibliography

Chapter 4. Piezoelectric Transduction (QCM)

4.1. General remarks and basic principles

4.2. Theoretical aspects of the quartz microbalance

4.3. Applications of quartz microbalances

4.4. Bibliography

Chapter 5. Metal Oxide Gas Sensors

5.1. Introduction: gas detection and micro-sensors

5.2. Catalytic sensors

5.3. Potentiometric sensors

5.4. Semi-conductor sensors

5.5. Future developments

5.6. Bibliography

Chapter 6. Molecular Material-based Conductimetric Gas Sensors

6.1. Molecular semiconductors

6.2. Molecular material-based conductimetric devices

6.3. Oxidizing or electron providing compound sensors

6.4. Volatile organic compound (VOC) sensors

6.5. Bibliography

Chapter 7. Responses and Electrical Properties of Gas Microsensors

7.1. Introduction

7.2. Response of a gas sensor

7.3. Chemical microsensors

7.4. Modeling conductivity of the sensitive layer with WO3 gas microsensors in the air in the presence of ozone

7.5. Impedance spectroscopy on gas sensors

7.6. Selectivity in gas sensors

7.7. Electronic noise spectroscopy in gas microsensors

7.8. Conclusion

7.9. Bibliography

Chapter 8. Gas Microsensor Technology

8.1. Introduction

8.2. Metal oxide gas sensor technology

8.3. New generation of wireless gas sensors

8.4. Conclusion

8.5. Bibliography

Chapter 9. Multisensors: Measurements and Behavior Models

9.1. Introduction

9.2. Modeling the behavior of multisensors

9.3. Performance of gas sensors, influence on prediction computation

9.4. Example with four sensors

9.5. Bibliography

Chapter 10. Development of Microtechnologies for the Realization of Chemical, Biochemical and/or Biological Microsensors

10.1. Introduction

10.2. Chemical sensors

10.3. Development of silicon and polymer microtechnologies applied to chemical sensors

10.4. Conclusion

Chapter 11. Development of Micro-preconcentrators for the Detection of Gaseous Species at Trace Level

11.1. Introduction

11.2. Preconcentration principle/preconcentration factors

11.3. Adsorption phenomena

11.4. Adsorbing materials

11.5. Development of preconcentrators

11.6. Conclusion

11.7. Bibliography

Chapter 12. Microfluidics: Manipulation of Nanovolume Samples

12.1. Introduction

12.2. The physics of microfluidic flows: simplified Navier-Stokes equations

12.3. Hydrodynamic flow: concept of microfluidic resistance

12.4. Electro-osmotic flow

12.5. Drop microfluidics: two-phase flows

12.6. Conclusion

12.7. Bibliography

Chapter 13. Electrochemical Biosensors

13.1. Defining biosensors

13.2. Principle behind biosensors

13.3. Characteristics

13.4. Enzymatic biosensors

13.5. Affinity sensors

13.6. Conclusion

Chapter 14. Fiber-optic Biosensors

14.1. Introduction

14.2. Biomolecules and recognition

14.3. Fiber-optics

14.4. Fiber-optic sensor applications

14.5. Conclusion

14.6. Bibliography

Chapter 15. In Vivo Analyses with Electrochemical Microsensors

15.1. Introduction

15.2. In vivo electrochemical detection of neurotransmitters

15.3. Conclusion

15.4. Bibliography

Chapter 16. Microbial Biosensors for Environmental Applications

16.1. Pollution and environment

16.2. Introduction to biosensors

16.3. Microorganisms

16.4. Microbial biosensors

16.5. Examples of microbial biosensors in environmental applications

16.6. Bibliography

Chapter 17. Biofuel Cells

17.1. Presentation and risks

17.2. Principle and characterization of biofuel cells

17.3. Principle and characterization of a biofuel cell

17.4. Biofuel cell examples

17.5. Bibliography

List of Authors

Index

First published 2012 in Great Britain and the United States by ISTE Ltd and John Wiley & Sons, Inc.

Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced, stored or transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms and licenses issued by the CLA. Enquiries concerning reproduction outside these terms should be sent to the publishers at the undermentioned address:

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© ISTE Ltd 2012

The rights of René Lalauze to be identified as the author of this work have been asserted by him in accordance with the Copyright, Designs and Patents Act 1988.

Library of Congress Cataloging-in-Publication Data

Chemical sensors and biosensors / edited by Rene Lalauze.p. cm.Includes bibliographical references and index.ISBN 978-1-84821-403-31. Electrochemical sensors. 2. Biosensors. I. Lalauze, Rene.TP159.E37.C44 2012543--dc23

2012012116

British Library Cataloguing-in-Publication DataA CIP record for this book is available from the British LibraryISBN:978-1-84821-403-3

Preface

This book, written at the La Rochelle technical school, organized by Club Micro Capteurs Chimiques (the Chemical Microsensors Club), represents a major breakthrough in the detection of gaseous, ionic and biological environments.

Throughout this scientific work, fundamental and technological aspects concerning different types of sensors are examined by specialists from the world of research and academia.

These are sensitive elements, which are liable to interfere with gaseous spaces, semi-conductor materials, molecular crystals, ionic conductors and polymers all of which will be examined here.

In terms of detecting ionic environments in water solutions, these include silver salts, glasses and polymers which are the focus of detailed studies.

Biological recognition is approached using interactions between spaces for detection such as heavy metals, organophosphorus components or DNA and sensitive components such as enzymes, algae, bacteria or yeast.

Electrical, electrochemical, piezoelectric, mechanical, optical and biological transducers are commonly examined in terms of their implementation, production and performance in specific contexts and applications.

Microreactors, nanotechnology and flexible technologies also feature in this work, which focuses on the delicate problem of processing information over neural networks or electronic noses.

This book should therefore serve as a particularly useful and interesting tool for Masters and PhD students working in the field of chemical sensors, biosensors and biochips.

Chapter 1

Chemical and Biological Recognition1

A (bio)chemical sensor allows the direct transduction of a concentration of (bio)chemical spaces into an electrical signal. This device includes a chemical or biological recognition feature coupled with a transduction system.

This chapter focuses on the main materials enabling the recognition of target spaces to be detected: gas molecules, ions, biological spaces.

1.1. Gas molecule recognition [MN 08]

Three types of recognition material are used: the exchange of electrons with inorganic or organic semi-conductor materials, the exchange of ions with ionic conductive materials and selective sorption in polymer matrices.

1.1.1. Utilizing metallic oxides as semi-conductor materials for detecting gases

It has been known for a long time (since the 1950s) that metallic oxides can present various semi-conductor properties, depending on the type of gaseous atmosphere they are in. We will examine different theories focusing on an example of the electronic catalyst theory or, more generally, the laws of adsorption. The use of metallic oxides as gas sensitive materials was introduced in the 1960s by Japanese researchers. As such, in this same period, Seiyma showed that variations in electric resistance of a ZnO film allowed the detection of reductor gases and Taguchi proposed the first gas sensor with porous SnO2-based ceramics.

Metallic oxides with a general MO formula can present challenges to stoichiometry. The semi-conductive nature of these oxides comes from their ability to exceed or go under the stoichiometric amount. These challenges lead to more or less ionized punctual defects in crystalline networks in these oxides. This can consist of anionic gaps or interstitial cations which release electrons and make the semi-conductive material n-type, or even cationic gaps or interstitial anions which release holes of electrons and which make the semi-conductive material p-type.

Figure 1.1.A type of semi-conductive metallic oxide: oxygen gaps (n-type)

For example SnO2 has a tendency to be sub-stoichiometric in oxygen (written as SnO2X). According to punctual defect laws, oxygen gaps lead to free electrons in the oxide crystalline network, and therefore an increase in the concentration of free carriers, which provides the n character of the semiconductor.

For SnO2, the band-gap-width is 3.5 eV and the donor levels are singly or doubly ionized oxygen gaps. As with every semi-conductor, an increase in temperature causes the electrons to move from these points towards the conduction bands. Next to the surface, the band diagram is modified by the electronic surface states, therefore creating a specific zone called the space charge zone. This can be the result of intrinsic faults in the materials surface and is especially due to the adsorption of atoms and foreign molecules. Variations in the space zone charge are directly linked to the extraction or injection of electrons by acceptor or donor spaces. This is the basis of gas detection properties by metallic oxides. The adsorption of oxygen on a n-type semi-conductor, such as SnO, leads to an electronic transfer towards the adsorbed molecules and as a result a decrease in the electric conductivity. This can be written as the following equation: