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Project Code [2001-PHD-5-M1]
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Project title
Development of a novel biosensor for the rapid detection of phenols in environmental samples
Primary Funding Agency
Environmental Protection Agency
Co-Funding Organisation(s)
n/a
Lead Organisation
University College Dublin (UCD)
Lead Applicant
Kevin O'Connor
Project Abstract
This study is concerned with the purification and characterisation of oxidases namely tyrosinase and laccase from Pseudomonas putida F6. Relevant physico-chemical characteristics of the enzyme were elucidated. The biotechnological potential of tyrosinase in crude cell extracts as well as the purified enzyme as a biosensor for the detection of phenols was also examined. A comparison of the spectrophotometric detection and quantification of a number of 4-substituted phenols by two sources of the enzyme tyrosinase (Agaricus bisporus (mushroom) versus Pseudomonas putida) is described here. Incubation of either source of tyrosinase with selected 4-substituted phenols results in the formation of coloured products that absorb light maximally within a narrow wavelength range (400-423 nm). The inclusion of the nucleophile 3-methyl-2-benzothiazolinone (MBTH) in the tyrosinase assay resulted in more intensely coloured products that also absorb light within a narrow wavelength range (440-475 nm). The molar extinction coefficient of the reaction products in the tyrosinase and tyrosinase-MBTH assay differed dramatically with values of between 714-1580 M-1cm-1 and 14213-26563 M-1cm-1 respectively. The addition of MBTH improved the sensitivity of the reaction between 1.3 and 100 fold depending on the substrate and source of the enzyme. The limit of detection of 4-substituted phenols also varied according to substrate and the source of enzyme used in the assay. The lowest detectable concentration of 4-substituted phenol was 2.5 M 4-hydroxyphenoxyacetic acid in the presence of mushroom tyrosinase and MBTH and 2.5 M 2-(4-hydroxyphenyl) ethanol in the presence of cell extract of Pseudomonas putida F6 and MBTH.
Grant Approved
�76,184.28
Research Hub
Green and Circular Economy
Research Theme
Waste and Resources Management
Initial Projected Completion Date
n/a