This review provides an overview of the key aspects of designing ionophore-based optical sensors (IBOS). Exact response functions are developed and compared with a simplified, generalized equation. We also provide a brief introduction into less established but promising working principles, namely dynamic response and exhaustive exchange. Absorbance and fluorescence are the main optical readout strategies used in the evaluation of a sensor response, but they usually require a robust referencing technique for real-world applications. Established referencing schemes using IBOS as well as those from other optical sensors are also discussed. Finally, the power of recently developed photoresponsive ion extraction/release systems is outlined and discussed in view of dynamically switchable IBOS or regenerative exhaustive exchange IBOS.


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Literature Cited

  1. Meier RJ, Schreml S, Wang X, Landthaler M, Babilas P, Wolfbeis OS. 1.  2011. Simultaneous photographing of oxygen and pH in vivo using sensor films. Angew. Chem. 123:4611085–88 [Google Scholar]
  2. Ungerböck B, Charwat V, Ertl P, Mayr T. 2.  2013. Microfluidic oxygen imaging using integrated optical sensor layers and a color camera. Lab Chip 13:81593 [Google Scholar]
  3. Glud RN, Tengberg A, Kühl M, Hall POJ, Klimant I, Holst G. 3.  2001. An in situ instrument for planar O2 optode measurements at benthic interfaces. Limnol. Oceanogr. 46:82073–80 [Google Scholar]
  4. Harjes DI, Dubach JM, Rosenzweig A, Das S, Clark HA. 4.  2010. Ion-selective optodes measure extracellular potassium flux in excitable cells. Macromol. Rapid Commun. 31:217–21 [Google Scholar]
  5. Shortreed M, Bakker E, Kopelman R. 5.  1996. Miniature sodium-selective ion-exchange optode with fluorescent pH chromoionophores and tunable dynamic range. Anal. Chem. 68:2656–62 [Google Scholar]
  6. Citterio D, Takeda J, Kosugi M, Hisamoto H, Sasaki S. 6.  et al. 2007. pH-independent fluorescent chemosensor for highly selective lithium ion sensing. Anal. Chem. 79:1237–42 [Google Scholar]
  7. Watts AS, Urbas AA, Moschou E, Gavalas VG, Zoval JV. 7.  et al. 2007. Centrifugal microfluidics with integrated sensing microdome optodes for multiion detection. Anal. Chem. 79:8046–54 [Google Scholar]
  8. Shortreed MR, Dourado S, Kopelman R. 8.  1997. Development of a fluorescent optical potassium-selective ion sensor with ratiometric response for intracellular applications. Sens. Actuators B 38:8–12 [Google Scholar]
  9. Koronczi I, Reichert J, Heinzmann G, Ache HJ. 9.  1998. Development of a submicron optochemical potassium sensor with enhanced stability due to internal reference. Sens. Actuators B 51:188–95 [Google Scholar]
  10. Brasuel M, Kopelman R, Miller TJ, Tjalkens R, Philbert MA. 10.  2001. Fluorescent nanosensors for intracellular chemical analysis: decyl methacrylate liquid polymer matrix and ion-exchange-based potassium PEBBLE sensors with real-time application to viable rat C6 glioma cells. Anal. Chem. 73:2221–28 [Google Scholar]
  11. Totu E, Josceanu AM, Covington AK. 11.  2001. Improved potassium-selective membrane using valinomycin as ionophore for ion-selective microdevices. Mater. Sci. Eng. C 18:87–91 [Google Scholar]
  12. Johnson RD, Badr IHA, Barrett G, Lai S, Lu Y. 12.  et al. 2001. Development of a fully integrated analysis system for ions based on ion-selective optodes and centrifugal microfluidics. Anal. Chem. 73:3940–46 [Google Scholar]
  13. Retter R, Peper S, Bell M, Tsagkatakis I, Bakker E. 13.  2002. Flow cytometric ion detection with plasticized poly(vinyl chloride) microspheres containing selective ionophores. Anal. Chem. 74:5420–25 [Google Scholar]
  14. Xu C, Wygladacz K, Retter R, Bell M, Bakker E. 14.  2007. Multiplexed flow cytometric sensing of blood electrolytes in physiological samples using fluorescent bulk optode microspheres. Anal. Chem. 79:9505–12 [Google Scholar]
  15. Wygladacz K, Bakker E. 15.  2005. Imaging fiber microarray fluorescent ion sensors based on bulk optode microspheres. Anal. Chim. Acta 532:61–69 [Google Scholar]
  16. Xie L, Qin Y, Chen H-Y. 16.  2013. Direct fluorescent measurement of blood potassium with polymeric optical sensors based on upconverting nanomaterials. Anal. Chem. 85:2617–22 [Google Scholar]
  17. O'Neill S, Conway S, Twellmeyer J, Egan O, Nolan K, Diamond D. 17.  1999. Ion-selective optode membranes using 9-(4-diethylamino-2-octadecanoatestyryl)-acridine acidochromic dye. Anal. Chim. Acta 398:1–11 [Google Scholar]
  18. Tsagkatakis L, Peper S, Retter R, Bell M, Bakker E. 18.  2001. Monodisperse plasticized poly(vinyl chloride) fluorescent microspheres for selective ionophore-based sensing and extraction. Anal. Chem. 73:6083–87 [Google Scholar]
  19. Xu C, Wygladacz K, Retter R, Bell M, Bakker E. 19.  2007. Multiplexed flow cytometric sensing of blood electrolytes in physiological samples using fluorescent bulk optode microspheres. Anal. Chem. 79:249505–12 [Google Scholar]
  20. Wang E, Zhu L, Ma L, Patel H. 20.  1997. Optical sensors for sodium, potassium and ammonium ions based on lipophilic fluorescein anionic dye and neutral carriers. Anal. Chim. Acta 357:85–90 [Google Scholar]
  21. Bychkova V, Shvarev A. 21.  2009. Surface area effects on the response mechanism of ion optodes: a preliminary study. Anal. Chem. 81:7416–19 [Google Scholar]
  22. Seiler K, Wang K, Bakker E, Morf WE, Rusterholz B. 22.  et al. 1991. Characterization of sodium-selective optode membranes based on neutral ionophores and assay of sodium in plasma. Clin. Chem. 37:81350–55 [Google Scholar]
  23. Wang EJ, Meyerhoff ME. 23.  1993. Anion-selective optical sensing with metalloporphyrin-doped polymeric films. Anal. Chim. Acta 283:673–82 [Google Scholar]
  24. Badr IHA, Johnson RD, Diaz M, Hawthorne MF, Bachas LG. 24.  2000. A selective optical sensor based on [9]mercuracarborand-3, a new type of ionophore with a chloride complexing cavity. Anal. Chem. 72:4249–54 [Google Scholar]
  25. Pimenta AM, Araujo AN, Conceicao M, Montenegro BSM, Pasquini C. 25.  et al. 2004. Chloride-selective membrane electrodes and optodes based on an indium(III) porphyrin for the determination of chloride in a sequential injection analysis system. J. Pharm. Biomed. Anal. 36:49–55 [Google Scholar]
  26. Wygladacz K, Bakker E. 26.  2005. Imaging fiber microarray fluorescent ion sensors based on bulk optode microspheres. Anal. Chim. Acta 532:61–69 [Google Scholar]
  27. Xu C, Qin Y, Bakker E. 27.  2004. Optical chloride sensor based on [9]mercuracarborand-3 with massively expanded measuring range. Talanta 63:180–84 [Google Scholar]
  28. Tan SSS, Hauser PC, Wang KM, Fluri K, Seiler K. 28.  et al. 1991. Reversible optical sensing membrane for the determination of chloride in serum. Anal. Chim. Acta 255:35–44 [Google Scholar]
  29. Capitán-Vallvey LF, Arroyo-Guerrero E, Fernández-Ramos MD, Cuadros-Rodriguez L. 29.  2006. Logit linearization of analytical response curves in optical disposable sensors based on coextraction for monovalent anions. Anal. Chim. Acta 561:156–63 [Google Scholar]
  30. Ceresa A, Qin Y, Peper S, Bakker E. 30.  2003. Mechanistic insights into the development of optical chloride sensors based on the [9]mercuracarborand-3 ionophore. Anal. Chem. 75:133–40 [Google Scholar]
  31. Hisamoto H, Watanabe K, Oka H, Nakagawa E, Spichiger UE, Suzuki K. 31.  1994. Flow-through type chloride ion selective optodes based on lipophilic organometallic chloride adducts and a lipophilic anionic dye. Anal. Sci. 10:615–22 [Google Scholar]
  32. Wang EJ, Ma L, Zhu L, Stivanello CM. 32.  1997. Calcium optical sensors based on lipophilic anionic dye and calcium-selective organophosphate ionophore or neutral carrier. Anal. Lett. 30:33–44 [Google Scholar]
  33. Capel-Cuevas S, de Orbe-Paya I, Santoyo-Gonzalez F, Capitan-Vallvey LF. 33.  2009. Double-armed crown ethers for calcium optical sensors. Talanta 78:1484–88 [Google Scholar]
  34. Hisamoto H, Yasuoka M, Terabe S. 34.  2006. Integration of multiple-ion-sensing on a capillary-assembled microchip. Anal. Chim. Acta 556:164–70 [Google Scholar]
  35. Hisamoto H, Kim KH, Manabe Y, Sasaki K, Minamitani H, Suzuki K. 35.  1997. Ion-sensitive and selective active waveguide optodes. Anal. Chim. Acta 342:31–39 [Google Scholar]
  36. Hisamoto H, Watanabe K, Nakagawa E, Siswanta D, Shichi Y, Suzuki K. 36.  1994. Flow-through type calcium ion selective optodes based on novel neutral ionophores and a lipophilic anionic dye. Anal. Chim. Acta 299:179–87 [Google Scholar]
  37. Capitan-Vallvey LF, Fernandez-Ramos MD, Galvez PAD, Santoyo-Gonzalez F. 37.  2003. Characterisation of a transparent optical test strip for quantification of water hardness. Anal. Chim. Acta 481:139–48 [Google Scholar]
  38. Qin Y, Mi YM, Bakker E. 38.  2000. Determination of complex formation constants of 18 neutral alkali and alkaline earth metal ionophores in poly(vinyl chloride) sensing membranes plasticized with bis(2-ethylhexyl)sebacate and o-nitrophenyloctylether. Anal. Chim. Acta 421:207–20 [Google Scholar]
  39. Siswanta D, Hisamoto H, Sato S, Matsumoto Y, Koike Y. 39.  et al. 1997. Magnesium ion-selective optodes based on a neutral ionophore and a lipophilic cationic dye. Anal. Sci. 13:429–35 [Google Scholar]
  40. Lapresta-Fernández A, Capitán-Vallvey LF. 40.  2011. Environmental monitoring using a conventional photographic digital camera for multianalyte disposable optical sensors. Anal. Chim. Acta 706:328–37 [Google Scholar]
  41. Wygladacz K, Qin Y, Wroblewski W, Bakker E. 41.  2008. Phosphate-selective fluorescent sensing microspheres based on uranyl salophene ionophores. Anal. Chim. Acta 614:77–84 [Google Scholar]
  42. Xie X, Pawlak M, Tercier-Waeber M-L, Bakker E. 42.  2012. Direct optical carbon dioxide sensing based on a polymeric film doped with a selective molecular tweezer-type ionophore. Anal. Chem. 84:3163–69 [Google Scholar]
  43. Shortreed MR, Barker SLR, Kopelman R. 43.  1996. Anion-selective liquid-polymer optodes with fluorescent pH chromoionophores, tunable dynamic range and diffusion enhanced lifetimes. Sens. Actuators B 35:217–21 [Google Scholar]
  44. Badr IHA.44.  2001. Nitrite-selective optical sensors based on organopalladium ionophores. Anal. Lett. 34:2019–34 [Google Scholar]
  45. Capitán-Vallvey LF, Fernández Ramos MD, Al-Natsheh M. 45.  2003. A disposable single-use optical sensor for potassium determination based on neutral ionophore. Sens. Actuators B 88:217–22 [Google Scholar]
  46. Hisamoto H, Miyashita N, Watanabe K, Nakagawa E, Yamamoto N, Suzuki K. 46.  1995. Ion sensing film optodes: disposable ion sensing probes for the determination of Na+, K+, Ca2+ and Cl concentrations in serum. Sens. Actuators B 29:378–85 [Google Scholar]
  47. Lapresta-Fernández A, Huertas R, Melgosa M, Capitán-Vallvey LF. 47.  2009. Colourimetric characterisation of disposable optical sensors from spectroradiometric measurements. Anal. Bioanal. Chem. 393:1361–66 [Google Scholar]
  48. He H, Jenkins K, Lin C. 48.  2008. A fluorescent chemosensor for calcium with excellent storage stability in water. Anal. Chim. Acta 611:197–204 [Google Scholar]
  49. Chan WH, Yang RH, Mo T, Wang KM. 49.  2002. Lead-selective fluorescent optode membrane based on 3,3′,5,5′-tetramethyl-N-(9-anthrylmethyl)benzidine. Anal. Chim. Acta 460:123–32 [Google Scholar]
  50. Antico E, Lerchi M, Rusterholz B, Achermann N, Badertscher M. 50.  et al. 1999. Monitoring Pb2+ with optical sensing films. Anal. Chim. Acta 388:327–38 [Google Scholar]
  51. Ceresa A, Pretsch E. 51.  1999. Determination of formal complex formation constants of various Pb2+ ionophores in the sensor membrane phase. Anal. Chim. Acta 395:41–52 [Google Scholar]
  52. Bualom C, Ngeontae W, Nitiyanontakit S, Ngamukot P, Imyim A. 52.  et al. 2010. Bulk optode sensors for batch and flow-through determinations of lead ion in water samples. Talanta 82:660–67 [Google Scholar]
  53. Lerchi M, Bakker E, Rusterholz B, Simon W. 53.  1992. Lead-selective bulk optodes based on neutral ionophores with subnanomolar detection limits. Anal. Chem. 64:1534–40 [Google Scholar]
  54. Ongun MZ, Ertekin K, Gocmenturk M, Ergun Y, Suslu A. 54.  2012. Copper ion sensing with fluorescent electrospun nanofibers. Spectrochim. Acta A 90:177–85 [Google Scholar]
  55. Liu X, Qin Y. 55.  2008. Ion-exchange reaction of silver(I) and copper(II) in optical sensors based on thiaglutaric diamide. Anal. Sci. 24:1151–56 [Google Scholar]
  56. Xie X, Li X, Ge Y, Qin Y, Chen H-Y. 56.  2010. Rhodamine-based ratiometric fluorescent ion-selective bulk optodes. Sens. Actuators B 151:71–76 [Google Scholar]
  57. Firooz AR, Ensafi AA, Kazemifard N, Sharghi H. 57.  2012. A highly sensitive and selective bulk optode based on benzimidazol derivative as an ionophore and ETH5294 for the determination of ultra trace amount of silver ions. Talanta 101:171–76 [Google Scholar]
  58. Hisamoto H, Nakagawa E, Nagatsuka K, Abe Y, Sato S. 58.  et al. 1995. Silver ion-selective optodes based on novel thia ether compounds. Anal. Chem. 67:1315–21 [Google Scholar]
  59. Wygladacz K, Radu A, Xu C, Qin Y, Bakker E. 59.  2005. Fiber-optic microsensor array based on fluorescent bulk optode microspheres for the trace analysis of silver ions. Anal. Chem. 77:4706–12 [Google Scholar]
  60. Kuswandi B, Nuriman, Dam HH, Reinhoudt DN, Verboom W. 60.  2007. Development of a disposable mercury ion-selective optode based on trityl-picolinamide as ionophore. Anal. Chim. Acta 591:208–13 [Google Scholar]
  61. Sadeghi S, Doosti S. 61.  2008. Novel PVC membrane bulk optical sensor for determination of uranyl ion. Sens. Actuators B 135:139–44 [Google Scholar]
  62. Lerchi M, Reitter E, Simon W. 62.  1994. Uranyl ion-selective optode based on neutral ionophores. Fresenius J. Anal. Chem. 348:272–76 [Google Scholar]
  63. Joshi JM, Pathak PN, Pandey AK, Manchanda VK. 63.  2008. Optode for uranium(VI) determination in aqueous medium. Talanta 76:60–65 [Google Scholar]
  64. Puyol M, Salinas I, Garces I, Villuendas F, Llobera A. 64.  et al. 2002. Improved integrated waveguide absorbance optodes for ion-selective sensing. Anal. Chem. 74:3354–61 [Google Scholar]
  65. Bühlmann P, Pretsch E, Bakker E. 65.  1998. Carrier-based ion-selective electrodes and bulk optodes. 2. Ionophores for potentiometric and optical sensors. Chem. Rev. 98:1593–688 [Google Scholar]
  66. Ozawa S, Hauser PC, Seiler K, Tan SSS, Morf WE, Simon W. 66.  1991. Ammonia-gas-selective optical sensors based on neutral ionophores. Anal. Chem. 63:6640–44 [Google Scholar]
  67. Seiler K, Wang K, Bakker E, Morf WE, Rusterholz B. 67.  et al. 1991. Characterization of sodium-selective optode membranes based on neutral ionophores and assay of sodium in plasma. Clin. Chem. 37:81350–55 [Google Scholar]
  68. Huber C, Werner T, Krause C, Wolfbeis OS, Leiner MJP. 68.  1999. Overcoming the pH dependency of optical sensors: a pH-independent chloride sensor based on co-extraction. Anal. Chim. Acta 398:137–43 [Google Scholar]
  69. Krause C, Werner T, Huber C, Wolfbeis OS, Leiner MJ. 69.  1999. pH-insensitive ion selective optode: a coextraction-based sensor for potassium ions. Anal. Chem. 71:1544–48 [Google Scholar]
  70. Krause C, Werner T, Huber C, Wolfbeis OS. 70.  1999. Emulsion-based fluorosensors for potassium featuring improved stability and signal change. Anal. Chem. 71:5304–8 [Google Scholar]
  71. Charlton SC, Fleming RL, Zipp A. 71.  1982. Solid-phase colorimetric determination of potassium. Clin. Chem. 28:1857–61 [Google Scholar]
  72. Ueberfeld J, Parthasarathy N, Zbinden H, Gisin N, Buffle J. 72.  2002. Coupling fiber optics to a permeation liquid membrane for heavy metal sensor development. Anal. Chem. 74:664–70 [Google Scholar]
  73. Bakker E, Lerchi M, Rosatzin T, Rusterholz B, Simon W. 73.  1993. Synthesis and characterization of neutral hydrogen ion-selective chromoionophores for use in bulk optodes. Anal. Chim. Acta 278:211–25 [Google Scholar]
  74. Bakker E, Bühlmann P, Pretsch E. 74.  1997. Carrier-based ion-selective electrodes and bulk optodes. 1. General characteristics. Chem. Rev. 97:3083–132 [Google Scholar]
  75. Ishikawa J, Sakamoto H, Mizuno T, Doi K, Otomo M. 75.  1998. Acyclic and cyclic polythiamonoaza- and polythiadiaza-alkane hydrazone derivatives as chromogenic extractants for silver ion. Analyst 123:201–7 [Google Scholar]
  76. Lan BTT, Toth K. 76.  1998. Characterization of chromogenic calix[4]arene derivative based ion-selective optical sensors. Anal. Sci. 14:191–97 [Google Scholar]
  77. Sanchez-Pedreno C, Ortuno JA, Albero MI, Garcia MS, Valero MV. 77.  2000. Development of a new bulk optode membrane for the determination of mercury(II). Anal. Chim. Acta 414:195–203 [Google Scholar]
  78. Kacmaz S, Ertekin K, Suslu A, Ozdemir M, Ergun Y. 78.  et al. 2011. Emission-based sub-nanomolar silver sensing with electrospun nanofibers. Sens. Actuators B 153:205–13 [Google Scholar]
  79. He HR, Mortellaro MA, Leiner MJP, Young ST, Fraatz RJ, Tusa JK. 79.  2003. A fluorescent chemosensor for sodium based on photoinduced electron transfer. Anal. Chem. 75:549–55 [Google Scholar]
  80. Crespo GA, Bakker E. 80.  2012. Ionophore-based ion optodes without a reference ion: electrogenerated chemiluminescence for potentiometric sensors. Analyst 137:4988–94 [Google Scholar]
  81. Crespo GA, Mistlberger G, Bakker E. 81.  2012. Electrogenerated chemiluminescence for potentiometric sensors. J. Am. Chem. Soc. 134:205–7 [Google Scholar]
  82. Crespo GA, Mistlberger G, Bakker E. 82.  2011. Electrogenerated chemiluminescence triggered by electroseparation of Ru(bpy)32+ across a supported liquid membrane. Chem. Commun. 47:11644–46 [Google Scholar]
  83. Rosatzin T, Bakker E, Suzuki K, Simon W. 83.  1993. Lipophilic and immobilized anionic additives in solvent polymeric membranes of cation-selective chemical sensors. Anal. Chim. Acta 280:197–208 [Google Scholar]
  84. Mistlberger G, Crespo GA, Xie X, Bakker E. 84.  2012. Photodynamic ion sensor systems with spiropyran: photoactivated acidity changes in plasticized poly(vinyl chloride). Chem. Commun. 48:5662–64 [Google Scholar]
  85. Watanabe K, Nakagawa E, Yamada H, Hisamoto H, Suzuki K. 85.  1993. Lithium ion-selective optical sensor-based on a novel neutral ionophore and a lipophilic anionic dye. Anal. Chem. 65:2704–10 [Google Scholar]
  86. Bakker E, Simon W. 86.  1992. Selectivity of ion-sensitive bulk optodes. Anal. Chem. 64:1805–12 [Google Scholar]
  87. Lerchi M, Reitter E, Simon W, Pretsch E, Chowdhury DA, Kamata S. 87.  1994. Bulk optodes based on neutral dithiocarbamate ionophores with high selectivity and sensitivity for silver and mercury cations. Anal. Chem. 66:1713–17 [Google Scholar]
  88. Puyol M, del Valle M, Garcés I, Villuendas F, Domínguez C, Alonso J. 88.  1999. Integrated waveguide absorbance optode for chemical sensing. Anal. Chem. 71:5037–44 [Google Scholar]
  89. Kim K, Minamitani H. 89.  2000. Active optical poly(vinylchloride) thin-film waveguide ion sensor. Opt. Rev. 7:152–57 [Google Scholar]
  90. Kovacs B, Nagy G, Dombi R, Toth K. 90.  2003. Optical biosensor for urea with improved response time. Biosens. Bioelectron. 18:111–18 [Google Scholar]
  91. Kang Y, Kampf JW, Meyerhoff ME. 91.  2007. Optical fluoride sensor based on monomer-dimer equilibrium of scandium(III)-octaethylporphyrin in a plasticized polymeric film. Anal. Chim. Acta 598:295–303 [Google Scholar]
  92. Clark PMS, Broughton PMG. 92.  1983. An evaluation of the Ames Seralyzer. J. Anal. Methods Chem. 5:22–26 [Google Scholar]
  93. Walter B.93.  1983. Dry reagent chemistries in clinical analysis. Anal. Chem. 55:498A–514A [Google Scholar]
  94. Palma AJ, Ortigosa JM, Lapresta-Fernández A, Fernández-Ramos MD, Carvajal MA, Capitán-Vallvey LF. 94.  2008. Portable light-emitting diode-based photometer with one-shot optochemical sensors for measurement in the field. Rev. Sci. Instrum. 79:103105 [Google Scholar]
  95. Palma A, Lapresta-Fernández A, Ortigosa-Moreno JM, Fernández-Ramos MD, Carvajal MA, Capitán-Vallvey LF. 95.  2006. A simplified measurement procedure and portable electronic photometer for disposable sensors based on ionophore-chromoionophore chemistry for potassium determination. Anal. Bioanal. Chem. 386:1215–24 [Google Scholar]
  96. Fernández-Ramos DM, Greluk M, Palma AJ, Arroyo-Guerrero E, Gomez-Sanchez J, Capitán-Vallvey LF. 96.  2008. The use of one-shot sensors with a dedicated portable electronic radiometer for nitrate measurements in aqueous solutions. Meas. Sci. Technol. 19:095204 [Google Scholar]
  97. Prabhakaran D, Nanjo H, Matsunaga H. 97.  2007. Naked eye sensor on polyvinyl chloride platform of chromo-ionophore molecular assemblies: a smart way for the colorimetric sensing of toxic metal ions. Anal. Chim. Acta 601:108–17 [Google Scholar]
  98. Garcia A, Erenas MM, Marinetto ED, Abad CA, de Orbe-Paya I. 98.  et al. 2011. Mobile phone platform as portable chemical analyzer. Sens. Actuators B 156:350–59 [Google Scholar]
  99. Lapresta-Fernández A, Capitán-Vallvey LF. 99.  2011. Multi-ion detection by one-shot optical sensors using a colour digital photographic camera. Analyst 136:3917–26 [Google Scholar]
  100. Ye N, Wygladacz K, Bakker E. 100.  2007. Absorbance characterization of microsphere-based ion-selective optodes. Anal. Chim. Acta 596:195–200 [Google Scholar]
  101. Xu C, Bakker E. 101.  2007. Multicolor quantum dot encoding for polymeric particle-based optical ion sensors. Anal. Chem. 79:3716–23 [Google Scholar]
  102. Dubach JM, Harjes DI, Clark HA. 102.  2007. Fluorescent ion-selective nanosensors for intracellular analysis with improved lifetime and size. Nano. Lett. 7:1827–31 [Google Scholar]
  103. Clark HA, Hoyer M, Philbert MA, Kopelman R. 103.  1999. Optical nanosensors for chemical analysis inside single living cells. 1. Fabrication, characterization, and methods for intracellular delivery of pebble sensors. Anal. Chem. 71:4831–36 [Google Scholar]
  104. Roe JN, Szoka FC, Verkman AS. 104.  1990. Fiber optic sensor for the detection of potassium using fluorescence energy transfer. Analyst 115:353–58 [Google Scholar]
  105. Wygladacz K, Bakker E. 105.  2007. Fluorescent microsphere fiber optic microsensor array for direct iodide detection at low picomolar concentrations. Analyst 132:268–72 [Google Scholar]
  106. Xie L, Qin Y, Chen H-Y. 106.  2012. Polymeric optodes based on upconverting nanorods for fluorescent measurements of pH and metal ions in blood samples. Anal. Chem. 84:1969–74 [Google Scholar]
  107. Freiner D, Kunz RE, Citterio D, Spichiger UE, Gale MT. 107.  1995. Integrated optical sensors based on refractometry of ion-selective membranes. Sens. Actuators B 29:277–85 [Google Scholar]
  108. Kurihara K, Nakamura K, Hirayama E, Suzuki K. 108.  2002. An absorption-based surface plasmon resonance sensor applied to sodium ion sensing based on an ion-selective optode membrane. Anal. Chem. 74:6323–33 [Google Scholar]
  109. Kurihara K, Ohkawa H, Iwasaki Y, Niwa O, Tobita T, Suzuki K. 109.  2004. Fiber-optic conical microsensors for surface plasmon resonance using chemically etched single-mode fiber. Anal. Chim. Acta 523:165–70 [Google Scholar]
  110. Kurihara K, Ohtsu M, Yoshida T, Abe T, Hisamoto H, Suzuki K. 110.  1999. Micrometer-sized sodium ion-selective optodes based on a “tailed” neutral ionophore. Anal. Chem. 71:3558–66 [Google Scholar]
  111. Spiess AC, Zavrel M, Ansorge-Schumacher MB, Janzen C, Michalik C. 111.  et al. 2008. Model discrimination for the propionic acid diffusion into hydrogel beads using lifetime confocal laser scanning microscopy. Chem. Eng. Sci. 63:3457–65 [Google Scholar]
  112. Kuwana E, Liang F, Sevick-Muraca EM. 112.  2004. Fluorescence lifetime spectroscopy of a pH-sensitive dye encapsulated in hydrogel beads. Biotechnol. Prog. 20:1561–66 [Google Scholar]
  113. Huber C, Klimant I, Krause C, Wolfbeis OS. 113.  2001. Dual lifetime referencing as applied to a chloride optical sensor. Anal. Chem. 73:2097–103 [Google Scholar]
  114. Tohda K, Gratzl M. 114.  2006. Micro-miniature autonomous optical sensor array for monitoring ions and metabolites 1: design, fabrication, and data analysis. Anal. Sci. 22:383–88 [Google Scholar]
  115. Tohda K, Gratzl M. 115.  2006. Micro-miniature autonomous optical sensor array for monitoring ions and metabolites 2: color responses to pH, K+ and glucose. Anal. Sci. 22:937–41 [Google Scholar]
  116. Cantrell K, Erenas MM, de Orbe-Paya I, Capitán-Vallvey LF. 116.  2010. Use of the hue parameter of the hue, saturation, value color space as a quantitative analytical parameter for bitonal optical sensors. Anal. Chem. 82:531–42 [Google Scholar]
  117. Xie X, Mistlberger G, Bakker E. 117.  2012. Reversible photodynamic chloride-selective sensor based on photochromic spiropyran. J. Am. Chem. Soc. 134:16929–32 [Google Scholar]
  118. Mistlberger G, Xie X, Pawlak M, Crespo GA, Bakker E. 118.  2013. Photoresponsive ion extraction/release systems: dynamic ion optodes for calcium and sodium based on photochromic spiropyran. Anal. Chem. 85:2983–90 [Google Scholar]

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