University of North Florida
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Contact Info

Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Email: schalk@unf.edu
Website: @unf

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Jurgen Polster

Abbrev:
Polster, J.
Other Names:
Jürgen Polster
Address:
Lehrstuhl für Biologische Chemie, Technical University of Munich, D-85350 Freising-Weihenstephan, Germany
Phone:
+49-8161-713-684
Fax:
+49-8161-713-583

Citations 6

"Simultaneous Determination Of Penicillin And Ampicillin By Spectral Fiberoptic Enzyme Optodes And Multivariate Data-analysis Based On Transient Signals Obtained By Flow Injection Analysis"
Talanta 1995 Volume 42, Issue 12 Pages 2065-2072
Jürgen Polster*, Gertraud Prestel, Markus Wollenweber, Gerolf Kraus and Günter Gauglitz

Abstract: A multicomponent detection system using optical biosensors and flow injection analysis is described. The analysis of mixtures containing penicillin and ampicillin was realised by evaluating dynamic measurements of Phenol Red spectra in penicillinase optodes in combination with a diode array spectrometer. A variety of optodes has been produced by changing the composition of the receptor gel and the working pH. A set of characteristic quantities (describing dynamic and static features) could be obtained for each optode. These were used to compare the predictivity of classical multivariate calibration methods as well as of an artificial neural network, In addition, different algorithms were applied for the evaluation of the spectral data in order to select the most appropriate method for feature extraction. In consequence, the information obtained from the multivariate calibration models was used to set up an optimal sensor array consisting of four optodes with different types of penicillinase at different working pH. (25 references)
Penicillin Ampicillin Sensor Sensor Calibration Multivariate calibration Optosensing Neural network Optical fiber

"Application Of Optrodes In FIA-based Fermentation Process Control Using The Software Package FIACRE"
Sens. Actuat. B 1993 Volume 11, Issue 1-3 Pages 407-412
M. Busch, F. Gutberlet, W. Höbel, J. Polster*, H. -L. Schmidt and M. Schwenk

Abstract: A description is given of biosensors for ethanol and urea that can be used in fermentation processes. The ethanol sensor measures NADH fluorescence during an enzymatic reaction involving alcohol dehydrogenase and aldehyde dehydrogenase. The urea sensor is based on measuring a change in the fluorescence of fluorescein. Both sensors can be used for controlling fermentation processes involving the production or consumption of ethanol and urea. A description is given of an Enterobacteriaceae Proteus vulgaris fermentation that is monitored by a urea optode controlled by a FIACRE (Flow injection Analysis: Computer Regulated and Evaluated) software package. The lifetime of the urease optrode can be long.
Ethanol Urea Fermentation broth Fluorescence Sensor Optrode Computer Process control

"Software FIACRE: Bioprocess Monitoring On The Basis Of Flow Injection Analysis Using Simultaneously A Urea Optode And A Glucose Luminescence Sensor"
J. Biotechnol. 1993 Volume 31, Issue 3 Pages 327-343
M. Busch, W. Höbel and J. Polster*

Abstract: Various computer programs for large-scale bioprocess control and optimization have been developed as well as software for simple laboratory routine analysis. In comparison, software can hardly be found that works on laboratory scale and provides the control of complex flow injection analysis (FIA) systems, multisubstrate determination, data evaluation as well as minimal process control abilities. The sensors applied can be of different type (luminometric or other optical as well as electrochemical biosensors). The development of such a software may be very helpful for the transfer of FIA/biosensor systems from the state of development to industrial processes. Hence, each analyzing system--even a well established biosensor--has to be individually adapted to the process, a task which is best done under laboratory conditions. Such a flexible, computer- controlled FIA system for research level based on the software FIACRE is presented. Five FIA/(bio)sensor system can be controlled simultaneously. Additionally, common temperature and pH recordings are possible. Determinations of substrate concentrations are performed by means of calibration curves which can be recorded at different times. This allows supervising the activities of the sensors during a cell cultivation and controlling the bioprocess, e.g. by adding substrate to a cell culture. The automated monitoring of the degradation of glucose and urea by two different optical sensing principles during a cell cultivation under the control of one microcomputer is presented for the first time. For this purpose, already well examined biosensors (a urease optode and a luminometric glucose sensor) were employed and their properties discussed under the aspect of working in real cultivation media. It will also be shown that substrates being of interest for bioprocess control can be detected by slight modifications of known reactions. For example, substrates of NADH-dependent enzymatic reactions can be detected by the luminol chemiluminescence system, and optodes can be employed for pH, penicillin and glucose determination.
Glucose Urea Ethanol Fermentation broth Chemiluminescence Optrode Sensor Computer Process monitoring Optimization

"Evaluation Of Data Produced By Optode Arrays Under Flow Injection Analysis (FIA) Conditions Using A Partial Least Squares Method (PLS2)"
J. Biochem. Biophys. Methods 1999 Volume 41, Issue 1 Pages 1-11
Markus Wollenweber and Jürgen Polster

Abstract: Transient diffuse reflectance spectra in the visible wavelength region from an enzyme optode were evaluated to determine artificial mixtures consisting of penicillin and ampicillin simultaneously. In order to achieve a discrimination of the samples the optode operated at two different working pH values. Using an appropriate FIA modus a linear range in the increase and decrease of the time-dependent signal was registered which could be easily fitted by means of ordinary linear regression. In this way characteristic static and dynamic features of the enzyme catalyzed reaction could be extracted for the evaluation by partial least-squares (PLS). The pre-processed raw data were differently weighted and the optimal number of primary factors was each selected by full cross validation. The interpretation of the spectral loadings and the correlation matrix identifies redundant variables resulting in a model with an optimal number of variables. The results obtained with this model show that the straightforward linear regression can be a sufficient approach to avoid the introduction of systematic errors in online pre-processing of data.

"Application Of Fuzzy-logic In Multicomponent Analysis By Optrodes"
Biosens. Bioelectron. 1997 Volume 12, Issue 9-10 Pages 917-923
Markus Wollenweber, Jürgen Polster*, Thomas Becker and Hanns-Ludwig Schmidt

Abstract: Fuzzy logic can be a useful tool for the determination of substrate concentrations applying optode arrays in combination with flow injection analysis, UV-VIS spectroscopy and kinetics. The transient diffuse reflectance spectra in the visible wavelength region from four optodes were evaluated to carry out the simultaneous determination of artificial mixtures of ampicillin and penicillin. The discrimination of the samples was achieved by changing the composition of the receptor gel and working pH. Different algorithms of pre-processing were applied on the data to reduce the spectral information to a few analytic-specific variables. These variables were used to develop the fuzzy model. After calibration the model was validated by an independent test data set. (C) 1997 Elsevier Science Limited. 21 References
Ampicillin Penicillin Spectrophotometry Sensor Optosensing Multicomponent Chemometrics Fuzzy logic Kinetic

"Penicillinase Optrodes: Substrate Determinations Using Batch, Continuous-flow And Flow Injection Analysis Operation Conditions"
Biosens. Bioelectron. 1992 Volume 7, Issue 8 Pages 549-557
W. Höbel, A. Papperger and J. Polster*

Abstract: The penicillinase (E.C. 3.5.2.6 type I, from Bacillus cereus) optrodes were prepared in polyacrylamide gels using acrylamide - NN'-methylene-bisacrylamide - fluorescein isothiocyanate - dextran in sodium phosphate buffer, pH 7, containing NNN'N'-tetramethylethylenediamine, or in gelatin gels using gelatin - DMSO - 5(6)-carboxyfluorescein N-hydroxysuccinimide ester solution Schematic systems are given for the optrodes to be used in the batch mode or flow injection analysis mode and by continuous-flow. Fluorimetric measurements were made with an Oriel 3090 pulsed-light optical-fiber photometer with a bifurcated optical waveguide with statistically mixed fibers at the common end. A bandpass filter was used to isolate the excitation wavelength at 490 nm with a longpass filter to measure the emitted light above 505 nm. Both optrodes had similar sensitivity, concentration. ranges for the determination of benzylpenicillin and response times when compared with existing electrochemical optical sensors. There is a decrease in sensitivity in the order continuous-flow > batch > flow injection analysis. Determination of penicillin G is shown with 2 different sensor types and with 3 different working conditions for each sensor. A universal sensor head was constructed for this purpose which allows use in either batch, continuous-flow, or flow injection analysis (FIA) mode. In addition, 2 different immobilization techniques are compared. While the simple entrapment of penicillinase and fluorescein (coupled as isothiocyanate to dextran) in polyacrylamide gel shows good stability with time, the crosslinked gelatin-penicillinase-FLUOS optode loses its activity after 1 wk. On the other hand, the sensitivity and concentration. range for determination of penicillin G are similar for both polyacrylamide and gelatin optodes. Both optodes have comparable response times of about 60 s (or 10 s using low integration time for signal processing). Comparing all 3 different working conditions, there is a decrease in sensitivity in the order continuous-flow > batch > FIA.
Optrode Sensor Fluorescence Optical fiber Method comparison Immobilized enzyme