Chemical sensors based on fiber optics

Abstract

The devices considered in this REPORT involve a reagent phase on the end of a fiber optic. In operation, interaction with analyte leads to a change in optical properties of the reagent phase, which is probed and detected through the fiber optic. Depending on the particular device, the optical property measured can be absorbance, reflectance, luminescence, or something else. An example of such a device would be a pH sensor based on an immobilized dye whose color or fluorescence properties vary with pH.The term optrode is used to describe these devices (I). This term, formed by combining "optical" and "electrode," emphasizes that in use optical sensors are very similar to electrodes. However, in operating principles they are quite different, offering new possibilities relative to electrodes while at the same time being subject to limitations and problems that are not observed with electrodes.Attractive features of optical sensors relative to electrodes include the following: % Because the signal is optical, it is not subject to electrical interference, % No "reference electrode" is required.% Because the reagent phase does not have to physically contact the CIRCLE 157 ON READER SERVICE CARD FREE CATALOG Witty and wonderful! ACS T-shirts Barbecue/lab aprons Tote bags And more! Experiment with a Chemist! I have Designer Genes! Chemistry Spoken Here! And lots more! Choose your sentiment and wear it dose to your heart with ACS sportswear. Sizes for men, women, and children. Quantity discounts, too.Call (202) 872-4588 or mail coupon below for your free catalog today.

A pH plate fluorosensor (optode) for early diagenetic studies of marine sediments

“…Over the past two decades, considerable effort has been directed toward the development of solute specific chemical sensors with optical detection (e.g., Harvey 1957;Peterson et al 1980;Seitz 1984;Lakowicz 1999). These optical sensors are often called optodes (derived from ␦ -the optical way) or optrodes (in analogy to the term electrode).…”

Characterization of Chromogenic Calix[4]arene Derivative Based Ion-Selective Optical Sensors

“…[1][2][3][4] In optical sensors the concentration dependent signal is a direct result of the interaction of the carrier/receptor molecule (ligand, ionophore) with metal ions or neutral molecules to be analyzed. This can be achieved by using ionophores with chromogenic groups in the neighborhood of the co-ordination sites (chromoionophores) or by the application of the same ionophores as in ion-selective electrodes in combination with a hydrogen selective chromoionophore.…”

Au and NiO nanocrystals doped into porous sol–gel SiO2films and the effect on optical CO detection

“…Some of the advantages of optical devices over conventional conductometry-based gas sensors lie in their high resistivity to electromagnetic noise, fire resistance, inactivity in flammable environments and also capability for remote control and informationt ransfer through optical fibre networks [1,2]. Furthermore new potential applications in multi-gas detection can be achieved using differences in the intensity, wavelength, phase and polarization of the output light signal [3].…”