Kinetic behavior of polymer-coated long-period-grating fiber-optic sensors.

A new method of analysis employing the time-dependent response of long-period-grating (LPG) fiber-optic sensors is introduced. The current kinetic approach allows analysis of the time-dependent wavelength shift of the sensor, in contrast to previous studies, in which the LPG sensing element has been operated in an equilibrium mode and modeled with Langmuir adsorption behavior. A detailed kinetic model presented is based on diffusion of the analyte through the outer protective membrane coating into the affinity coating, which is bound to the fiber cladding. A simpler phenomenological approach presented is based on measurement of the slope of the time-dependent response of the LPG sensor. We demonstrate the principles of the kinetic methods by employing a commercial Cu+2 sensor with a carboxymethylcellulose sensing element. The detailed mathematical model fits the time-dependent behavior well and provides a means of calibrating the concentration-dependent time response. In the current approach, copper concentrations below parts per 10(6) are reliably analyzed. The kinetic model allows early-time measurement for low concentrations of the analyte, where equilibration times are long. This kinetic model should be generally applicable to other affinity-coated LPG fiber-optic sensors.

[1]  C. Bunker,et al.  Spectral Properties of AOT-Protected CdS Nanoparticles: Quantum Yield Enhancement by Photolysis , 2003 .

[2]  Alan D. Kersey,et al.  Analysis of the response of long period fiber gratings to external index of refraction , 1998 .

[3]  Heather Patrick,et al.  Long period fibre gratings for structural bend sensing , 1998 .

[4]  Wei Zhang,et al.  Simultaneous refractive index and temperature measurement using cascaded long-period grating in double-cladding fibre , 2002 .

[5]  Daniel A. Zweifel,et al.  Interactions of functionalized carbon nanotubes with tethered pyrenes in solution , 2002 .

[6]  Byeong Ha Lee,et al.  Fibre-optic sensing applications of a pair of long-period fibre gratings , 2001 .

[7]  Kenneth T. V. Grattan,et al.  Fiber optic sensor technology: an overview , 2000 .

[8]  Anna Grazia Mignani,et al.  Long period gratings as solution concentration sensors , 2001 .

[9]  I. Bennion,et al.  Optical bend sensor based on measurement of resonance mode splitting of long-period fiber grating , 2000, IEEE Photonics Technology Letters.

[10]  David Sherrer,et al.  Grating-based optical-fiber-based corrosion sensors , 1996, Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring.

[11]  Gia-Wei Chern,et al.  A torsion sensor made of a corrugated long period fibre grating , 2001 .

[12]  Dexiu Huang,et al.  Highly sensitive chemical sensor based on the measurement of the separation of dual resonant peaks in a 100-μm-period fiber grating , 1999 .

[13]  Suresh G. Advani,et al.  A methodology for using long-period gratings and mold-filling simulations to minimize the intrusiveness of flow sensors in liquid composite molding , 2002 .

[14]  A. Vengsarkar,et al.  Optical fiber long-period grating sensors. , 1996, Optics letters.

[15]  Ian Bennion,et al.  Detection of organic aromatic compounds in paraffin by a long-period fiber grating optical sensor with optimized sensitivity , 2001 .

[16]  Kent A. Murphy,et al.  Real-time immunoassays using fiber optic long-period grating sensors , 1996, Photonics West.

[17]  Heather Patrick.  Self-aligning bipolar bend transducer based on long period grating written in eccentric core fibre , 2000 .

[18]  Edgar A. Mendoza,et al.  Evanescent wave sensor for detecting volatile organic compounds , 1999, Other Conferences.

[19]  S. James,et al.  Simultaneous temperature and bend sensing with long-period fiber gratings. , 2000, Optics letters.

[20]  John E. Sipe,et al.  Long-period fiber gratings as band-rejection filters , 1995 .

[21]  Ian Bennion,et al.  Bend sensing by measuring the resonance splitting of long-period fiber gratings , 2001 .