Glutamate optical biosensor based on the immobilization of glutamate dehydrogenase in titanium dioxide sol-gel matrix.

A simple and novel titania sol-gel derived optical biosensor coupled with carboxy seminaphthorhodamine-1-dextran (SNARF-1-dextran) as the fluorescent dye was fabricated for the determination of glutamate in water and biological samples. The NADH-dependent glutamate dehydrogenase (GLDH) was trapped in titania sol-gel derived matrix prepared by vapor deposition method. In addition, scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to characterize the surface morphology of the spots. SEM and AFM images showed that the deposition of titania precursor at 27 degrees C for 6.5h was found to be suitable to form transparent titania sol-gel matrix to encapsulate GLDH and fluorescent probe. AFM images showed that the roughness of TiO(2) surface increased from 2.16 nm in the absence of GLDH and SNARF to 37.8 nm after the immobilization. The developed titania biosensor has good analytical performance with water samples. A dynamic range between 0.04 and 10mM with the detection limit of 5.5 microM were observed. The responses to glutamate in biological samples also showed good performances, and the dynamic range and detection limit were 0.02-10mM and 6.7 microM, respectively. High precision with relative standard deviations of 4.2 and 10.7% in water and biological samples, respectively, were also demonstrated. In addition, the biosensor showed a relatively high storage stability over more than 1 month. Results obtained in this study clearly demonstrate that this simple vapor deposition method can be successfully used to form transparent titania sol-gel film for the fabrication of glutamate biosensors that are suitable for optical detection of glutamate in water and biological samples.

[1]  H. Ju,et al.  Preparation of porous titania sol-gel matrix for immobilization of horseradish peroxidase by a vapor deposition method. , 2002, Analytical chemistry.

[2]  J. Park,et al.  Microfabricated Conductometric Urea Biosensor Based on Sol‐Gel Immobilized Urease , 2000 .

[3]  John D. Brennan,et al.  Properties and applications of proteins encapsulated within sol–gel derived materials , 2002 .

[4]  R. Daniel,et al.  Glutamate dehydrogenase from the extremely thermophilic archaebacterial isolate AN1. , 1993, Biochimica et biophysica acta.

[5]  H. Tsai,et al.  Simultaneous determination of renal clinical analytes in serum using hydrolase- and oxidase-encapsulated optical array biosensors. , 2004, Analytical biochemistry.

[6]  Shaojun Dong,et al.  Sol-gel-derived titanium oxide/copolymer composite based glucose biosensor. , 2003, Biosensors & bioelectronics.

[7]  W. Tan,et al.  Two-dimensional biochemical imaging sensor for spatially resolved glutamate monitoring , 1999 .

[8]  F. Robb,et al.  Purification and characterization of NADP-specific alcohol dehydrogenase and glutamate dehydrogenase from the hyperthermophilic archaeon Thermococcus litoralis , 1994, Applied and environmental microbiology.

[9]  G. Jobst,et al.  Biosensor arrays for simultaneous measurement of glucose, lactate, glutamate, and glutamine. , 2002, Biosensors & bioelectronics.

[10]  John D. Brennan,et al.  Reagentless pH-based biosensing using a fluorescently-labelled dextran co-entrapped with a hydrolytic enzyme in sol–gel derived nanocomposite films , 2002 .

[11]  A. Palmer,et al.  Improved method for the measurement of glutamate and aspartate using capillary electrophoresis with laser induced fluorescence detection and its application to brain microdialysis. , 1997, Journal of chromatography. B, Biomedical sciences and applications.

[12]  D. Clark,et al.  Sol-gel encapsulated enzyme arrays for high-throughput screening of biocatalytic activity. , 2002, Biotechnology and bioengineering.

[13]  J. Oni,et al.  Simultaneous detection of the release of glutamate and nitric oxide from adherently growing cells using an array of glutamate and nitric oxide selective electrodes. , 2005, Biosensors & bioelectronics.

[14]  Ruey-an Doong,et al.  Simultaneous determination of pH, urea, acetylcholine and heavy metals using array-based enzymatic optical biosensor. , 2005, Biosensors & bioelectronics.

[15]  D. Avnir,et al.  Sol-gel-entrapped cholinesterases: a microtiter plate method for monitoring anti-cholinesterase compounds , 1998 .

[16]  M. Kennedy,et al.  Identification of Proteins in the Postsynaptic Density Fraction by Mass Spectrometry , 2000, The Journal of Neuroscience.

[17]  S. J. Martin,et al.  Synaptic plasticity and memory: an evaluation of the hypothesis. , 2000, Annual review of neuroscience.

[18]  C. Gerber,et al.  Immobilization of Antibodies on a Photoactive Self-Assembled Monolayer on Gold , 1996 .

[19]  Spyros Koinis,et al.  An optical spot test for the detection of dopamine in human urine using stabilized in air lipid films. , 2004, Analytical chemistry.

[20]  P. Zhang,et al.  Atomic force microscopy for the characterization of immobilized enzyme molecules on biosensor surfaces , 2001, Fresenius' journal of analytical chemistry.

[21]  Julia Cordek,et al.  Direct Immobilization of Glutamate Dehydrogenase on Optical Fiber Probes for Ultrasensitive Glutamate Detection , 1999 .

[22]  B. Belsham.  Glutamate and its role in psychiatric illness , 2001, Human psychopharmacology.

[23]  R. O'Neill,et al.  Polymer-enzyme composite biosensor with high glutamate sensitivity and low oxygen dependence. , 2005, Analytical chemistry.

[24]  R. R. Preston,et al.  A two-cell biosensor that couples neuronal cells to optically monitored fish chromatophores. , 2001, Biosensors & bioelectronics.

[25]  Sheila A. Grant,et al.  A sol–gel based fiber optic sensor for local blood pH measurements , 1997 .

[26]  M. Vohra,et al.  Enhanced photocatalytic activity of nafion-coated TiO2. , 2001, Environmental science & technology.

[27]  H. Ju,et al.  Amperometric biosensor for hydrogen peroxide based on hemoglobin entrapped in titania sol–gel film , 2003 .

[28]  H. Tsai,et al.  Sol–gel derived urease-based optical biosensor for the rapid determination of heavy metals , 2003 .

[29]  Huangxian Ju,et al.  Mediator-free phenol sensor based on titania sol-gel encapsulation matrix for immobilization of tyrosinase by a vapor deposition method. , 2003, Biosensors & bioelectronics.

[30]  S. Martin,et al.  Environmental Applications of Semiconductor Photocatalysis , 1995 .

[31]  T. Takano,et al.  Beyond the role of glutamate as a neurotransmitter , 2002, Nature Reviews Neuroscience.

[32]  A. Ballesteros,et al.  Bioencapsulation within synthetic polymers (Part 1): sol-gel encapsulated biologicals. , 2000, Trends in biotechnology.