PREFACE
The goal of textbook is to cover the full scope of modern electroanalytical
techniques and devices. The main emphasis is on electroanalysis, rather than
physical electrochemistry. The objective …
1
ABBREVIATIONS AND SYMBOLS
a
Activity
A
Absorbance
A
Area of Electrode
2
DAFTAR ISI
PREFACE…........ .......................................................................................................... 1
ABBREVIATIONS AND SYMBOLS .......................................................................... 2
DAFTAR ISI……. ......................................................................................................... 3
DAFTAR TABEL ........................................................................................................ 10
DAFTAR FIGURE ...................................................................................................... 11
CHAPTER 1
Fundamental Concepts .................................................................. 12
1 Why Electroanalysis?............................................................................................ 12
2 Faradaic Process.................................................................................................... 12
1.2 Mass Transpot-Controlled Reactions ............................................................. 12
1.21 Potensial-Step Experiment ....................................................................... 13
2.21 Potensial-Sweep Experiment ................................................................... 13
2.2 Reactions Controlled by the Rate of Electron Transfer ................................. 14
1.22 Activated Complex Theory ...................................................................... 14
3 The Electrical Double Layer ................................................................................. 14
4 Electrocapillary Effect .......................................................................................... 14
5 Supplementary Reading ........................................................................................ 14
6 References ............................................................................................................. 14
7 Questions............................................................................................................... 14
CHAPTER 2
Study of Electrode Reaction .......................................................... 15
3
1 Cyclic Voltammetry .............................................................................................. 15
1.1 Data Interpretation ......................................................................................... 15
1.11 Reversible Systems .................................................................................. 15
2.11 Irreversible and Quasi-Reversible Systems ............................................. 15
2.1 Study of Reaction Mechanisms ..................................................................... 15
3.1 Study of Adsorption Processes ...................................................................... 15
4.1 Quantitative Applications .............................................................................. 15
2 Spectroelectrochemistry ........................................................................................ 15
1.2 Experimental Arangement ............................................................................. 16
2.2 Principles and Applications ........................................................................... 16
3.2 Other Spectroelectrochemical and Spectroscopic Techniques ...................... 16
3 Scanning Probe Microscopy ................................................................................. 16
1.3 Scanning Tunneling Microscopy ................................................................... 16
2.3 Atomic Force Microscopy ............................................................................. 17
3.3 Scanning Electrochemical Microscopy.......................................................... 17
4 Electrochemical Quartz Crystal Microbalance ..................................................... 17
5 References ............................................................................................................. 17
6 Examples ............................................................................................................... 17
7 Questions............................................................................................................... 17
CHAPTER 3
Controlled Potential Techniques ................................................... 18
1 Chronoamperometry ............................................................................................. 18
4
2 Polarography ......................................................................................................... 18
3 Pulse Voltammetry................................................................................................ 18
1.3 Normal Pulse Voltammetry ........................................................................... 18
2.3 Differential Pulse Voltammetry ..................................................................... 19
3.3 Square Wave Voltammetry ............................................................................ 19
4.3 Staircase Voltammetry ................................................................................... 19
4 AC Voltammetry................................................................................................... 19
5 Stripping Analysis ................................................................................................. 19
1.5 Anodic Stripping Voltammetry...................................................................... 19
2.5 Potentiometric Stripping Analysis ................................................................. 19
3.5 Adsorptive Stripping Voltammetry and Potentiometry ................................. 19
4.5 Cathodic Stripping Voltammetry ................................................................... 19
5.5 Applications ................................................................................................... 20
6 Flow Analysis ....................................................................................................... 20
1.6 Principles........................................................................................................ 20
2.6 Cell Design..................................................................................................... 20
3.6 Mass Transport and Current Response .......................................................... 21
4.6 Detection Modes ............................................................................................ 21
7 References ............................................................................................................. 21
8 Examples ............................................................................................................... 21
9 Questions............................................................................................................... 21
5
CHAPTER 4
Practical Consideration .................................................................. 22
1 Electrochemical Cells ........................................................................................... 22
2 Solvents and Supporting Electrolytes ................................................................... 22
3 Oxygen Removal .................................................................................................. 22
4 Instrumentation ..................................................................................................... 22
5 Working Electrodes .............................................................................................. 22
1.5 Mercury Electrodes ........................................................................................ 22
2.5 Solid Electrodes ............................................................................................. 23
1.52 Rotating Disk and Ring Disk Electrodes ................................................. 23
2.52 Carbon Electrodes .................................................................................... 23
1.522 Glassy Carbon Electrodes .................................................................. 23
2.522 Carbon Paste Electrodes .................................................................... 24
3.522 Carbon Fiber Electrodes .................................................................... 24
3.52 Metal Electrodes ...................................................................................... 24
3.5 Chemically Modified Electrodes ................................................................... 24
1.53 Self Assembled Monolayers .................................................................... 24
2.53 Sol Gel Encapsulation of Reactive Species ............................................. 24
3.53 Electrocatalytic Modified Electrodes ....................................................... 24
4.53 Pre concentrating Electrodes.................................................................... 24
5.53 Permselective Coatings ............................................................................ 24
6.53 Conducting Polymers ............................................................................... 25
6
4.5 Microelectrodes.............................................................................................. 25
1.54 Diffusion at Microelectrodes ................................................................... 25
2.54 Configuration of Microelectrodes ............................................................ 25
3.54 Composite Electrodes .............................................................................. 25
6 References ............................................................................................................. 25
7 Examples ............................................................................................................... 26
8 Questions............................................................................................................... 26
CHAPTER 5
Potentiometry................................................................................. 27
1 Principles of Potentiometric Measurements ......................................................... 27
2 Ion Selective Electrodes ........................................................................................ 27
1.2 Glass Electrodes ............................................................................................. 27
1.21 pH Electrodes ........................................................................................... 27
2.21 Glass Electrodes for Other Cations .......................................................... 27
2.2 Liquid Membrane Electrodes ......................................................................... 27
1.22 Ion Exchanger Electrodes ........................................................................ 27
2.22 Neutral Carrier Electrodes ....................................................................... 27
3.2 Solid State Electrodes .................................................................................... 28
4.2 Coated Wire Electrodes ................................................................................. 28
3 Online and in Vivo Potentiometric Measurements ............................................... 28
4 References ............................................................................................................. 29
5 Examples ............................................................................................................... 29
7
6 Questions............................................................................................................... 29
CHAPTER 6
Electrochemical Sensors ................................................................ 30
1 Electrochemical Biosensors .................................................................................. 30
1.1 Enzyme Based Electrodes .............................................................................. 30
1.11 Impractical and Theoretical Considerations ............................................ 30
2.11 Enzyme Electrodes of Analytical Significance........................................ 30
1.112
Glucose sensors .............................................................................. 30
2.112
Ethanol Electrodes .......................................................................... 30
3.112
Urea Electrodes............................................................................... 30
4.112
Toxin (Enzyme Inhibition) Biosensors ........................................... 30
3.11 Tissues and Bacteria Electrodes............................................................... 31
2.1 Affinity Biosensors ........................................................................................ 31
1.12 Immunosensors ........................................................................................ 31
2.12 DNA Hybridization Biosensors ............................................................... 31
3.12 Receptor Based Sensors ........................................................................... 31
2 Gas Sensors ........................................................................................................... 31
1.2 Carbon Dioxide Sensors ................................................................................ 32
2.2 Oxygen Electrodes ......................................................................................... 32
3 Solid State Devices ............................................................................................... 32
1.3 Microfabrication of Solid State Sensor Assemblies ...................................... 32
2.3 Microfabrication Techniques ......................................................................... 32
8
4 Sensor Arrays ........................................................................................................ 32
5 References ............................................................................................................. 32
6 Examples ............................................................................................................... 32
7 Questions............................................................................................................... 32
INDEX………….. ....................................................................................................... 33
9
DAFTAR TABEL
Table 1 Properties of Controlled Potential Techniques ............................................ 12
Table 2 Functional Groups Reducible at the Dropping Mercury Electrode ............. 18
Table 3 Reprentative Application of Stripping Analysis .......................................... 20
Table 4 Commonly Used Membrane Barriers .......................................................... 25
Table 5 Some Common Enzyme Electrode .............................................................. 31
10
DAFTAR FIGURE
Figure 1
The Three Modes of Mass Transport ....................................................... 13
Figure 2
STM image of an electrochemically activated glassy carbon surface ...... 16
Figure 3
Design of a system for in-situ electrochemical scanning tunneling
microscopy................................................................................................ 17
Figure 4
The Dropping Mercury Electrode............................................................. 23
Figure 5
Coated Wire Ion Selective Electrode........................................................ 28
11
CHAPTER 1
Fundamental Concepts
1 Why Electroanalysis?
Electroanalytical techniques are concerned with the interplay between electricity and
chemistry, namely the measurements of …
Table 1 Properties of Controlled Potential Techniques
2 Faradaic Process
The objective of controlled-potensial electroanalytical experiments is to obtain a
current response that is related to the concentration of the target analyte. This
objective is …
1.2 Mass Transpot-Controlled Reactions
Mass transport occurs by three different modes :
12
Figure 1
The Three Modes of Mass Transport
1.21 Potensial-Step Experiment
Let us see, for example, what happens in a potensial-step experiment involving the
reduction of O to R, a …
2.21 Potensial-Sweep Experiment
Let us move to a voltammetric experiment involving a linear potensial scan, the
reduction of O to R and a quiescent …
13
2.2 Reactions Controlled by the Rate of Electron Transfer
In this section we consider experiments in which the current is controlled by the rate
of electron transfer (i.e., reactions with …
1.22 Activated Complex Theory
The effect of the operating potential upon the rate constans (equations 1-18 and 1-19)
can be …
3 The Electrical Double Layer
The electrical double layer is the array of charged particles and/or oriented dipoles
that exists at every material interface. In electrochemistry such a layer reflects the …
4 Electrocapillary Effect
Electrocapilarry is the study of interfacial tension as a function of the electrode
potential. Such a study can provide useful insight into …
5 Supplementary Reading
Several international journals bring together papers and reviews covering innovations
and trends in the field of electroanalytical chemistry :
6 References
J.R.Maloy, J. Chem. Educ., 60, 285 (1983)
7 Questions
Show or draw the concentration profile/gradient near the electrode surface during a
linear scan voltammetric experiment …
14
CHAPTER 2
Study of Electrode Reaction
1 Cyclic Voltammetry
Cyclic voltammetry is the most widely used techniques for acquiring qualitative
information about electrochemical reactions. The power of cyclic voltammetry results
…
1.1 Data Interpretation
The cyclic voltammogram is characterized by several important parameters. Four of
these observables, two …
1.11 Reversible Systems
The peak current for a reversible couple (at 25oC), is given by Randles-Sevcik
equation :
2.11 Irreversible and Quasi-Reversible Systems
For irreversible processes (those with sluggish electron exchange), the individual
peaks are reduced in …
2.1 Study of Reaction Mechanisms
One of the most important applications of cyclic voltammetry is for qualitative
diagnosis of chemical reactions that precede or succeed the …
3.1 Study of Adsorption Processes
Cyclic voltammetry can also be used for evaluating the interfacial behavior of
electroactive …
4.1 Quantitative Applications
Cyclic voltammetry can also be useful for quantitative purposes, based on
measurements of peak current (equation 2-1). Such …
2 Spectroelectrochemistry
The coupling of optical and electrochemical methods spectroelectrochemistry has
been employed for over …
15
1.2 Experimental Arangement
Optically transparent electrodes (OTEs), which enable light to be passed through …
2.2 Principles and Applications
The primary advantage of spectroelectrochemistry is the cross-correlation of
information from the simultaneous electrochemical and optical …
3.2 Other
Spectroelectrochemical
and
Spectroscopic
Techniques
In addition to UV-visible absorption measurements, other spectroscopic techniques
can be used for monitoring the dynamics …
3 Scanning Probe Microscopy
The recently developed scanning probe microscopies (SPM) promise to revolutionize
the understanding of electrode …
1.3 Scanning Tunneling Microscopy
Scanning tunneling microscopy (STM) has revolutionized the field …
Figure 2
STM image of an electrochemically activated glassy carbon surface
16
2.3 Atomic Force Microscopy
Atomic force microscopy (AFM) has become a standard technique for high resolution
imaging …
Figure 3
Design of a system for in-situ electrochemical scanning tunneling microscopy
3.3 Scanning Electrochemical Microscopy
The scanning tunneling microscope (STM) has led to several other variants …
4 Electrochemical Quartz Crystal Microbalance
The electrochemical quartz crystal microbalance (EQCM) is a powerful tool for
elucidating interfacial …
5 References
R.S.Nicholson and I.Shain …
6 Examples
Examples 2-1 The reversible oxidation of dopamine (DA) …
7 Questions
Explain and demonstrate clearly how spectroelectrochemistry can provide useful …
17
CHAPTER 3
Controlled Potential Techniques
The basis of all controlled potential techniques is the measurement of the
current response …
1 Chronoamperometry
Chronoamperometry involves stepping the potential of the working electrode from a
value …
2 Polarography
Polarography is a subclass of voltammetry in which the working electrode is the
dropping mercury electrode (DME). Because …
Table 2 Functional Groups Reducible at the Dropping Mercury Electrode
3 Pulse Voltammetry
Pulse voltammetry techniques, introduced by Baker and Jenkin (3), are aimed at
lowering the detection limits …
1.3 Normal Pulse Voltammetry
Normal pulse voltammetry consists of a series of pulses of increasing amplitude
applied …
18
2.3 Differential Pulse Voltammetry
Differential pulse voltammetry is an extremely useful technique for measuring trace
levels of organic and …
3.3 Square Wave Voltammetry
Square wave voltammetry is a large amplitude differential technique in which a
waveform composed of a symmetrical …
4.3 Staircase Voltammetry
Staircase voltammetry has been proposed as a useful tool for rejecting the background
charging current. The potential time …
4 AC Voltammetry
Alternating current (AC) voltammetry is a frequency domain technique that involves
the superimposition of a small amplitude …
5 Stripping Analysis
Stripping analysis is an extremely sensitive electrochemical technique for measuring
trace …
1.5 Anodic Stripping Voltammetry
Anodic stripping voltammetry (ASV) is the most widely used form of stripping
analysis. In the case, the metals …
2.5 Potentiometric Stripping Analysis
Potentiometric stripping analysis (PSA), known also as stripping potentiometry,
differs from ASV in methods used …
3.5 Adsorptive Stripping Voltammetry and Potentiometry
Adsorptive stripping analysis greatly enhances the scope of stripping measurements
toward numerous trace …
4.5 Cathodic Stripping Voltammetry
Cathodic stripping voltametry (CSV) is the “mirror image” of ASV. It involves
anodic depotition of the …
19
5.5 Applications
The remarkable sensitively, broad scope, and low cost of stripping analysis have led
to …
6 Flow Analysis
An electrochemical detector uses the electrochemical properties of target analytes for
their determination …
Table 3 Reprentative Application of Stripping Analysis
1.6 Principles
Electrochemical detection is usually performed by controlling the potential of the
working electrode at a …
2.6 Cell Design
A wide range of cell designs have been used for electrochemical monitoring of
flowing streams. The cell design must …
20
3.6 Mass Transport and Current Response
Well defined hydrodynamic conditions, with high rate of mass transport, are essential
for successful …
4.6 Detection Modes
The simplest, and by far the most common, detection scheme is the measurement of
the ...
7 References
D.Ilkovic, …
8 Examples
Examples 3-1 Voltammogram (a) …
9 Questions
Describes clearly the principle and operation of …
21
CHAPTER 4
Practical Consideration
The basic instrumentation required for controlled potential experiments is
relatively inexpensive …
1 Electrochemical Cells
Three electrode cells (e.g., Figure 4-1) are commonly used in controlled potential …
2 Solvents and Supporting Electrolytes
Electrochemical measurements are commonly carried out in a medium that consists of
solvent …
3 Oxygen Removal
The electrochemical reduction of oxygen usually proceeds via two well separated two
electron …
4 Instrumentation
Rapid advences in microelectronics, and in particular the introduction of operational
amplifiers, have …
5 Working Electrodes
The performance of the voltammetric procedure is strongly influenced by the material
of the working …
1.5 Mercury Electrodes
Mercury is a very attractive choice of electrode material because it has a high
hydrogen overvoltage that …
22
Figure 4
The Dropping Mercury Electrode
2.5 Solid Electrodes
The limited anodic potential range of mercury electrodes has precluded their utility
for monitoring …
1.52 Rotating Disk and Ring Disk Electrodes
The rotating disk electrode (RDE) is vertically mounted in the shaft of a synchronous
controllable …
2.52 Carbon Electrodes
Solid electrodes based on carbon are currently in widespread use in
electroanalysis, primarily because of their broad …
1.522 Glassy Carbon Electrodes
23
Glassy (or”vitreous”) carbon has been very popular because its excellent mechanical
…
2.522 Carbon Paste Electrodes
Carbon paste electrodes, which use graphite powder mixed with various water
immiscible organic …
3.522 Carbon Fiber Electrodes
The growing interest in ultramicroelectrodes (section …
3.52 Metal Electrodes
While a wide choice of noble metals is available, platinum and gold are the most
widely used metallic electrodes. Such …
3.5 Chemically Modified Electrodes
Chemically modified electrodes (CMEs) represent a modern approach to electrode
systems. These …
1.53 Self Assembled Monolayers
Spontaneously adsorbed monolayers of n-alkanethiols …
2.53 Sol Gel Encapsulation of Reactive Species
Another new and attractive route for tailoring electrode surfaces involves the low
temperature encapsulation …
3.53 Electrocatalytic Modified Electrodes
Often the desired redox reaction at the bare electrode involves slow electron transfer
kinetics …
4.53 Pre concentrating Electrodes
Preconcentrating CMEs, with surfaces designed for reacting and binding of target
analytes, hold …
5.53 Permselective Coatings
Permselective coatings offer to bring higher selectivity and stability to
electrochemical devices. This …
24
6.53 Conducting Polymers
Electronically conducting polymers (such as polypyrrole, poly thiophene, and
polyaniline) have …
Table 4 Commonly Used Membrane Barriers
4.5 Microelectrodes
Miniaturization is a growing trend in the field of analytical chemistry. The
miniaturization of working …
1.54 Diffusion at Microelectrodes
The total diffution limited current is composed of the planar flux diffusion
components :
2.54 Configuration of Microelectrodes
Electrodes of different materials have been miniaturized in many geometrical shapes
…
3.54 Composite Electrodes
Composite electrodes couple the advantages of single microelectrode systems with
significantly …
6 References
T.P.De Angelis, R.E.Bond, …
25
7 Examples
Examples 4-1 A rotating ring …
8 Questions
What are the advantages of …
26
CHAPTER 5
Potentiometry
1 Principles of Potentiometric Measurements
In potentiometry information on the compotition of a sample is obtained through the
…
2 Ion Selective Electrodes
The discussion of section …
1.2 Glass Electrodes
Glass electrodes are …
1.21 pH Electrodes
the most common potentiometric devices is the pH electrode. This electrode has been
widely …
2.21 Glass Electrodes for Other Cations
From the early days of galss pH electrodes, it was noticed that alkaline solutions
display …
2.2 Liquid Membrane Electrodes
Liquid membrane types ISEs, based on water immiscible liquid substances
impregnated in a …
1.22 Ion Exchanger Electrodes
One of the most successful liquid membrane electrodes is selective toward calcium.
Such an electrode relies on the ability …
2.22 Neutral Carrier Electrodes
In addition to charged liquid ion exchangers, liquid membrane electrodes often rely
…
27
3.2 Solid State Electrodes
Considerable work has been devoted to the development of solid membranes that are
selective primarily …
4.2 Coated Wire Electrodes
Coated wire electrodes (CWEs), introduced by Freiser in the mid 1970s, are prepared
by coating …
Figure 5
Coated Wire Ion Selective Electrode
3 Online and in Vivo Potentiometric Measurements
Various online monitoring systems can benefit from the inherent specificity, wide
scope, dynamic …
28
4 References
J.Koryta, …
5 Examples
Examples 5-1 Calculate the …
6 Questions
Discuss clearly the …
29
CHAPTER 6
Electrochemical Sensors
A chemical sensor is a small device that can be used for direct measurement
of the …
1 Electrochemical Biosensors
Electrochemical biosensors combine the analytical power of electrochemical
techniques with …
1.1 Enzyme Based Electrodes
Enzymes are proteins that catalyze chemical reactions in living systems. Such
catalysts are not …
1.11 Impractical and Theoretical Considerations
The operation of an enzyme electrode is illustrated in …
2.11 Enzyme Electrodes of Analytical Significance
1.112 Glucose sensors
The determination of glucose in blood plays a crucal role in the diagnosis and therapy
…
2.112 Ethanol Electrodes
The reliable sensing of ethanol is of great significance in various disciplines. The
enzymatic …
3.112 Urea Electrodes
The physiologically important substrate urea can be sensed based on the following …
4.112 Toxin (Enzyme Inhibition) Biosensors
Enzyme affectors (inhibitors and activators) that influence the rate of biocatalytic
reactions can also be measured. Sensing …
30
3.11 Tissues and Bacteria Electrodes
The limited stability of isolated enzymes, and the fact that some enzymes are
expensive or even …
Table 5 Some Common Enzyme Electrode
2.1 Affinity Biosensors
Affinity sensors exploit selective binding of certain biomolecules (e.g. antibodies …
1.12 Immunosensors
Most reported affinity biosensors are based on immunological reactions involving the
shape …
2.12 DNA Hybridization Biosensors
Nucletic acid recognition layers can be combined with electrochemical tranducers to
form new and important types of …
3.12 Receptor Based Sensors
Another new and promising avenue of sensing is the use of chemoreceptors as
biological recognition …
2 Gas Sensors
Real time monitoring of gases, such as carbon dioxide, oxygen, and ammonia, is of
great …
31
1.2 Carbon Dioxide Sensors
Carbon dioxide devices were originally developed by Severinghaus and Bralley …
2.2 Oxygen Electrodes
While most gas sensors rely on potentiometric detection, the important oxygen probe
…
3 Solid State Devices
The integration of chemically sensitivemembranes with solid state electronics has led
to the evolution …
1.3 Microfabrication of Solid State Sensor Assemblies
Other miniaturized solid state sensors can be …
2.3 Microfabrication Techniques
Microfabrication technology has made a considerable impact on the miniaturization of
electrochemical sensors and …
4 Sensor Arrays
So far we have discussed the one sensor/one analyte approach. However, arrays of
independent …
5 References
G.Sittamplam and …
6 Examples
Example 6-1 Chronoamperogram a …
7 Questions
Describe different …
32
INDEX
Absorbance, …
33
34