TY  - CHAP
A1  - Pijanowska, Dorota G.
A1  - Remiszewska, Elzbieta
T1  - pH-based detection of phenylalnine by potentiometric and colorimetric methods
N2  - In this paper, methods of sample preparation for potentiometric measurement of phenylalanine are presented. Basing on the spectrophotometric measurements of phenylalanine, the concentrations of reagents of the enzymatic reaction (10 mM L-Phe, 0,4 mM NAD+, 2U L-PheDH) were determined. Then, the absorption spectrum of the reaction product, NADH, was monitored (maximum peak at 340 nm). The results obtained by the spectrophotometric method were compared with the results obtained by the colourimetry, using pH indicators. The above-mentioned two methods will be used as references for potentiometric measurements of phenylalanine concentration.
KW  - Biosensor
KW  - Phenylalanine determination
KW  - enzymatic methods
KW  - pH-based biosensing
Y1  - 2006
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:a96-opus-1536
ER  - 
TY  - CHAP
A1  - Pijanowska, Dorota G.
A1  - Remiszewska, Elzbieta
A1  - Pederzolli, Cecilia
A1  - Lunelli, Lorenzo
A1  - Vendano, Michele
A1  - Canteri, Roberto
A1  - Dudzinski, Konrad
A1  - Kruk, Jerzy
A1  - Torbicz, Wladyslaw
T1  - Surface modification for microreactor fabrication
N2  - In this paper, methods of surface modification of different supports, i.e. glass and polymeric beads for enzyme immobilisation are described. The developed method of enzyme immobilisation is based on Schiff’s base formation between the amino groups on the enzyme surface and the aldehyde groups on the chemically modified surface of the supports. The surface of silicon modified by APTS and GOPS with immobilised enzyme was characterised by atomic force microscopy (AFM), time-of-flight secondary ion mass spectroscopy (ToF-SIMS) and infrared spectroscopy (FTIR). The supports with immobilised enzyme (urease) were also tested in combination with microreactors fabricated in silicon and Perspex, operating in a flow-through system. For microreactors filled with urease immobilised on glass beads (Sigma) and on polymeric beads (PAN), a very high and stable signal (pH change) was obtained. The developed method of urease immobilisation can be stated to be very effective.
KW  - Biosensor
KW  - Microreactors
KW  - surface modification
KW  - enzyme immobilisation
KW  - lab-on-a-chip
Y1  - 2006
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:a96-opus-1480
ER  -