Phenol red immobilized PVA membrane for an optical pH sensor with two determination ranges and long-term stability

Abstract A novel method was developed to immobilize phenol red into poly(vinyl alcohol) (PVA) membrane for an optical pH sensor with two determination ranges and long-term stability. Phenol red was first reacted with the formaldehyde to produce hydroxymethyl groups, and then attached to PVA membrane via the hydroxymethyl groups. The dynamic response ranges of the sensor membrane became somewhat wider than those of free forms, from pH 0–3 and pH 6.5–9.5 to 5 M [H+]–pH 3.0 and pH 6.5–10.5, respectively. Experimental results indicated common cations, such as Na+ and K+ showed insignificant influence when 0.1 M of the respective chloride salts were added. Moreover, the optode could perform fast response (within 20–50 s) and long-term stability (continuous use for at least 3 months).

[1]  Gerhard J. Mohr,et al.  Optical sensors for a wide pH range based on azo dyes immobilized on a novel support , 1994 .

[2]  W. Rudolf Seitz,et al.  pH sensor based on immobilized fluoresceinamine , 1982 .

[3]  W. Rudolf Seitz,et al.  Poly(vinyl alcohol) as a substrate for indicator immobilization for fiber-optic chemical sensors , 1989 .

[4]  S R Goldstein,et al.  Fiber optic pH probe for physiological use. , 1980, Analytical chemistry.

[5]  Jie Lin,et al.  Recent development and applications of optical and fiber-optic pH sensors , 2000 .

[6]  Stoyan Tzonkov,et al.  Membranes for optical pH sensors , 1993 .

[7]  Aleksandra Lobnik,et al.  pH optical sensors based on sol–gels: Chemical doping versus covalent immobilization , 1998 .

[8]  O. Wolfbeis.  Fiber-optic chemical sensors and biosensors. , 2000, Analytical chemistry.

[9]  Tianlu Chen,et al.  Phenolphthalein immobilized membrane for an optical pH sensor , 2004 .

[10]  Andrew B. Bocarsly,et al.  Fast and long term optical sensors for pH based on sol–gels , 2003 .

[11]  C. Dafu,et al.  Optical-fibre pH sensor , 1993 .

[12]  G. Hieftje,et al.  Optical time-of-flight chemical detection: absorption-modulated fluorescence for spatially resolved analyte mapping in a bidirectional distributed fiber-optic sensor. , 1998, Analytical chemistry.

[13]  T. P. Jones,et al.  Optical pH sensor based on the chemical modification of a porous polymer film , 1988 .

[14]  Helmut Offenbacher,et al.  Fluorescence optical sensors for continuous determination of near-neutral pH values , 1986 .

[15]  Zhihong Liu,et al.  Polymeric pH indicators immobilized PVA membranes for optical sensors of high basicity based on a kinetic process , 2004 .

[16]  M. Maeda,et al.  Spectrophotometric Analysis of the Relationship between Dissociation and Coloration, and of the Structural Formulas of Phenolphthalein in Aqueous Solution , 1996 .

[17]  W. Fabianowski,et al.  Optical sensor with active matrix built from polyelectrolytes–smart molecules mixture , 1998 .

[18]  Melody M. Anderson,et al.  Continuous pH monitoring in a perfused bioreactor system using an optical pH sensor. , 2002, Biotechnology and bioengineering.

[19]  A. Ensafi,et al.  Optical pH sensor based on chemical modification of polymer film , 1999 .