Integrated optical sensors based on refractometry of ion-selective membranes

D. Freiner, R. E. Kunz, D. Citterio, U. E. Spichiger, M. T. Gale

Research output: Contribution to journalArticlepeer-review

46 Citations (Scopus)


The properties of optode membranes to be used for realizing miniature integrated optical sensors based on refractometry have been investigated theoretically and experimentally. In situ referencing by using optode and reference membranes on the same chip is a powerful means to discriminate against unspecific effects. The plasticized polymer membranes provide the function of selective extraction and chemical recognition of the analyte. In experiments performed for a pair of such membranes, refractive index differences ≈3 × 10-3 per decade of molar Ca2+ concentration in buffered aqueous solutions have been observed. With the characterized type of sensing pad implanted in a miniature integrated optical device, a typical overall resolution of 0.7 to 0.07% in units of Ca2+ concentration was calculated.

Original languageEnglish
Pages (from-to)277-285
Number of pages9
JournalSensors and Actuators: B. Chemical
Issue number1-3
Publication statusPublished - 1995 Oct
Externally publishedYes


  • Integrated optical sensors
  • Ion-selective membranes
  • Refractometry

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Instrumentation
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Electrical and Electronic Engineering
  • Materials Chemistry


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