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Carrier-Based Ion-Selective Electrodes and Bulk Optodes. 2. Ionophores for Potentiometric and Optical Sensors

Buhlmann, P.; Pretsch, E.; Bakker, E. Chem. Rev. 1998, 98, 1593-1687

(368 publications cited this review by August 2003)

I. Introduction

The first ion-selective electrodes (ISEs) based on bulk membranes containing an ion carrier were introduced more than thirty years ago. It has been estimated that already by 1990 more than 7000 papers on ISEs had been published. ISEs form today one of the most important groups of chemical sensors. On the other hand, bulk membrane optodes have been known for only about ten years. However, a fairly large number of such optodes have been developed in short time because ionophores originally developed for ISEs can often be used without further modification and because the two types of sensors rely on very similar chemical equilibria.

The first of this pair of reviews2 gave a theoretical description of the two sensor types, discussing their response mechanisms, selectivities, detection limits, measuring ranges, response times, and life times. The simultaneous treatment emphasized similarities and differences in the theory of ISEs and optodes and was followed by a general discussion of the requirements on the polymer matrix, membrane solvent, ionic additive, and the carrier. Table 1 of the first of this pair of reviews gave a brief list of the analytes for which carrier-based ISEs and bulk optodes have been developed.

This review describes individual carrier-based ISEs and bulk optodes, ordered according to the analyte for which they have been developed. Many reviews on ISEs have been written, selected topics have been covered in the journal Ion-Selective Electrode Reviews, and a little known electronic database summarizes a large number of data on potentiometric sensors (for a first-time user some knowledge of Japanese seems necessary for utilizing this database). A more readily accessible data collection in book form tabulated selectivity data, detection limits, linear ranges, response slopes and life times of many solid and liquid membrane ISEs up to 1988. However, for many analytes, especially for anions and heavy metal ions, more new carrier-based ISEs have been reported in the last ten years than before. For other ions, as for example for several clinically relevant blood electrolytes, major improvements in sensor performance were achieved in the 1990s and several new classes of ionophores, such as the cup-shaped calixarenes, were introduced only fairly recently. Therefore, it is not surprising that among the roughly 120 most representative ISEs and optodes whose principal properties have been summarized in Appendix I almost two thirds have been described in reports published after 1990. This review is intended to document these new developments of carrier-based ISEs, presenting them together with those in the much younger field of the bulk membrane optodes, and tries to put them in a historical perspective. While other articles have reviewed optodes, this is probably the so far most complete review of bulk membrane optodes. This review is intended to be comprehensive enough to mention all analytes for which carrier-based ISEs or bulk membrane optodes have been developed and is supposed to refer to all classes of ionophores that were reported so far for use in bulk membrane ISEs and optodes. It should provide not only a wide overview of relevant work in the field but should also make it possible for the interested reader to quickly find references to specific sensors. For this purpose we have consulted a large number of original publications, reviews and books, searched the literature published between 1981 and November 1996 using the Science Citation Index, and verified many of the references in the original publications found by these means.

Contents

I. Introduction 5

II. Inorganic Cationic Analytes 9

II. 1. H+-Sensors 9

II. 2. Li+-Sensors 18

II. 3. Na+-Sensors 26

II. 4. K+-Sensors 38

II. 5. Rb+-Sensors 48

II. 6. Cs+-Sensors 49

II. 7. NH4+-Sensors 50

II. 8. Be2+-Sensors 52

II. 9. Mg2+-Sensors 53

II. 10. Ca2+-Sensors 61

II. 11. Sr2+-Sensors 70

II. 12. Ba2+-Sensors 71

II. 13. Mo(VI)-Sensors 75

II. 14. Fe(III)-Sensors 75

II. 15. Cu2+-Sensors 75

II. 16. Ag+-Sensors 78

II. 17. Zn2+-Sensors 84

II. 18. Cd2+-Sensors 86

II. 19. Hg2+-Sensors 87

II. 20. Tl+-Sensors 89

II. 21. Bi3+-Sensors 91

II. 22. Pb2+/PbA+-Sensors 91

II. 23. U(VI)-Sensors 96

II. 24. Sm(III)-Sensors 99

III. Inorganic Anionic Analytes 100

III. 1. CO32- and HCO3- Sensors 100

III. 2. SCN- Sensors 103

III. 3. NO2- Sensors 105

III. 4. NO3- Sensors 110

III. 5. OH- Sensors 111

III. 6. Phosphate Sensors 112

III. 7. Sulfide Sensors 114

III. 8. Sulfite Sensors 115

III. 9. Sulfate Sensors 116

III. 10. Cl- Sensors 117

III. 11. ClO4- Sensors 122

III. 12. SeO32- Sensors 123

III. 13. I- and I3- Sensors 123

III. 14. Sensors for Metal Cyano Complexes 126

IV. Organic Ionic Analytes 127

IV. 1. Sensors for Organic Ammonium Ions 127

IV. 2. Sensors for Guanidinium, Guanidinium Derivatives and Creatinine 133

IV. 3. Sensors for Carboxylates 135

IV. 4. A Sensor for 2-Hydroxybenzhydroxamate 140

IV. 5. Sensors for Nucleotides 141

IV. 6. Sensors for Ionic Surfactants 143

IV. 7. Sensors for Polyionic Analytes such as Heparin and Protamine 145

V. Neutral Analytes 147

V. 1. CO2 Sensors 147

V. 2. Sensors for Ammonia and Organic Amines 148

V. 3. Sensors for Humidity and Water 150

V. 4. SO2 Sensors 151

V. 5. Sensors for Alcohols and Non-Ionic Surfactants 152

V. 6. Sensors for O2 154

VI. Conclusions 156

VII. Acknowledgments 159

VIII. References 160

Appendix I: Properties of a Selection of Representative ISEs and Bulk Optodes 213

Appendix II: Abbreviations 229


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