pH-based Detection of Phenylalnine by Potentiometric and Colorimetric Methods
نویسندگان
چکیده
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.
منابع مشابه
Enzyme-based Colorimetric and Potentiometric Biosensor for Detecting Pb (II) Ions in Milk
The aim of the present work was to study a simple colorimetric and potentiometric biosensor based on urease inhibition by Pb (II) ions for its estimation in milk samples. Urease immobilized on nylon membrane by hydrosol gel method was used as the biocomponent to demonstrate the metal effect on the enzyme activity using phenol red as the pH indicator. A lower limit detection of 38.6μm was achiev...
متن کاملIon-Selective Carbon Paste Electrode Based on 2-Amino-N-benzthioazolyl Benzamide (ABTB) for Determination of Copper (II) by Potentiometric Method
2-Amino-N-benzthioazolyl benzamide (ABTB) was synthesized, characterized and used for thefabrication of a potentiometric sensor for Cu2+ metal ions. The electrode exhibits linear response to Cu(II) over a wide concentration range (4.79×10 -8 – 1.85×10 -1 M) with Nernstian slope of 30 ± 1.5 mVper decade. The electrode can be used in the pH range from 2 to 9. It has a fast response time of about1...
متن کاملA New Potentiometric Sensor for Determination and Screening Phenylalanine in Blood Serum Based on Molecularly Imprinted Polymer
Methods routinely utilized for detection of phenylalanine in new-born blood consist of enzymatic assays, lacking sensitivity and HPLC assays which are expensive and time-consuming to conduct. We, here, report for the first time, the construction of a phenylalanine sensitive electrode, on the basis of a selective molecularly imprinted polymer, offering sensitivity, economy and ease of use for th...
متن کاملA New Potentiometric Sensor for Determination and Screening Phenylalanine in Blood Serum Based on Molecularly Imprinted Polymer
Methods routinely utilized for detection of phenylalanine in new-born blood consist of enzymatic assays, lacking sensitivity and HPLC assays which are expensive and time-consuming to conduct. We, here, report for the first time, the construction of a phenylalanine sensitive electrode, on the basis of a selective molecularly imprinted polymer, offering sensitivity, economy and ease of use for th...
متن کاملSelective Potentiometric Sensor for Isoniazid Ultra-Trace Determination Based on Fe3O4 Nanoparticles Modified Carbon Paste Electrode (Fe3O4/CPE)
Significant effects of magnetic iron oxide (Fe3O4) nanoparticles on the potentiometric behavior of carbon paste electrode for bio determination of Isoniazid aromatic drug (INH) were studied. The electrochemical performance of modified Fe3O4/CPE was investigated. The constructed Fe3O4/CPE showed high precision, sensitivity ...
متن کامل