The effect of ionic species on pH dependent response of silica coated optical fibers

Optical fiber pH sensors functionalized with a gold nanoparticle (AuNP)/porous silica film were developed. The transmission of light through the fiber is affected by the change in the refractive index of the porous silica-based nanocomposite coated film as ionic species are concentrated into the coating film when the silica surface becomes negatively charged with increasing pH. To investigate the dependence of the response on the ionic species in solution, we report the optical response of Au/silica film coated fibers in a variety of salt solutions. The response is indeed sensitive to different ionic species in solution. The details of the response are likely also sensitive to the microstructure of the porous silica-based sensing layer.

[1]  C. Clark,et al.  Theory and applications of atomic and ionic polarizabilities , 2010, 1004.3567.

[2]  Colette McDonagh,et al.  Optical chemical pH sensors. , 2014, Analytical chemistry.

[3]  J. Rayss,et al.  Ion adsorption in the porous sol–gel silica layer in the fibre optic pH sensor , 2002 .

[4]  M. Borkovec,et al.  Aggregation and charging of colloidal silica particles: effect of particle size. , 2005, Langmuir : the ACS journal of surfaces and colloids.

[5]  S. Wade,et al.  Fluorescence intensity ratio technique for optical fiber point temperature sensing , 2003 .

[6]  R. Kopelman,et al.  Analytical properties and sensor size effects of a micrometer-sized optical fiber glucose biosensor. , 1996, Analytical chemistry.

[7]  W. M. Haynes.  CRC Handbook of Chemistry and Physics , 1990 .

[8]  Lei Wang,et al.  Detection of ion adsorption at solid–liquid interfaces using internal reflection ellipsometry , 2015 .

[9]  Congjun Wang,et al.  Novel silica surface charge density mediated control of the optical properties of embedded optically active materials and its application for fiber optic pH sensing at elevated temperatures. , 2015, Nanoscale.

[10]  Guo-Li Shen,et al.  An optical fiber chemical sensor for mercury ions based on a porphyrin dimer. , 2002, Analytical chemistry.

[11]  Anbo Wang,et al.  Optical fiber pressure sensor based on photoelasticity and its application , 1992 .

[12]  Kent A. Murphy,et al.  Optical fiber pressure sensors for adaptive wings , 1997, Smart Structures.

[13]  Nélia Alberto,et al.  Optical Sensors Based on Plastic Fibers , 2012, Sensors.

[14]  Ingo Klimant,et al.  Optical Fiber Sensor for Biological Oxygen Demand , 1994 .

[15]  M. Borkovec,et al.  Adsorption of monovalent and divalent cations on planar water-silica interfaces studied by optical reflectivity and Monte Carlo simulations. , 2011, The Journal of chemical physics.

[16]  Congjun Wang,et al.  Optical waveguide modeling of refractive index mediated pH responses in silica nanocomposite thin film based fiber optic sensors , 2016 .

[17]  David G. Grier,et al.  The charge of glass and silica surfaces , 2001 .

[18]  S. Yee,et al.  A fiber-optic chemical sensor based on surface plasmon resonance , 1993 .

[19]  Luc Thévenaz,et al.  Distributed fiber‐optic temperature sensing for hydrologic systems , 2006 .

[20]  T. Tadros,et al.  Adsorption of potential-determining ions at the silica-aqueous electrolyte interface and the role of some cations , 1968 .