Development of acetylcholinesterase biosensor for the detection of pesticides

Download

index.pdf

Date

2010

Author

Kavruk, Murat

Metadata

Show full item record

Item Usage Stats

235
views

88
downloads

Pesticides are natural or artificial molecules aimed to kill, or mitigate any harmful organism. Although their use in agriculture provides us with an increased crop yield, remains of chemicals on the products creates health concerns in society. Organophosphates and carbamates are two groups of insecticides. Although they are far more lethal against insects and small animals, they can also cause poisoning in humans through the inhibition of acetylcholinesterase enzyme (AChE) that plays an important role in human nervous system. Therefore, the detection of these compounds is crucial. The conventional methods for the detection of these compounds are expensive, time-consuming and need expertise. In this study, a fast, disposable, cheap and accurate acetylcholinesterase biosensor was developed to detect organophosphate and carbamate-based pesticide residues. By means of adsorption method, AChE, the chromophore 5,5'-Dithio-bis(2-nitrobenzoic acid) (DTNB) and artificial substrate acetylthiocholine (ATCh) were immobilized on the supporting material. In optimization studies; from 3 to 15U/mL concentrations were experimented for AChE, 1 to 5mM DTNB and 1 to 5mM ATCh concentration gradients were used. v As a result of the optimization studies 12U/mL ACHE concentration, 5mM DTNB concentration and 5mM ATCh concentration were determined for constructing a pesticide biosensor. Detection limit of malathion, an organophosphate-based insecticide was found as 2.5ppm in 5% methanol solution. The biosensor conserved its integrity between pH 4 and 8, and gave false positive results after pH 10. Stability studies showed that, biosensor retained its activity for at least 60 days at 4°C to discrimnate between positive and negative controls.

Subject Keywords

Environmental pollution.

URI

http://etd.lib.metu.edu.tr/upload/12612403/index.pdf
https://hdl.handle.net/11511/19946

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Treatability of chromite ore processing waste by leaching Ünlü, Kahraman (SAGE Publications, 2001-06-01) Developing treatment and disposal strategies and health-based clean-up standards for chromium containing wastes continues to be an important environmental regulatory issue because of the opposing solubility and toxicity characteristics of chromium species under diverse environmental conditions. In this study, leaching characteristics of total Cr and Cr(VI) were investigated using laboratory column studies. The data obtained from the experimental studies were analysed to assess the treatability of chromite o...
A model for optimal operation of land-treatment sites for oily wastes Ünlü, Kahraman (SAGE Publications, 2001-06-01) Land treatment as a disposal technology has been extensively used for the disposal of oily wastes. Effective management of land treatment sites require optimal operation of the system in order to achieve the fastest and most complete degradation of petroleum hydrocarbons without contamination of the environment. This paper describes a model that can be used for optimising the operation of land treatment sites for oily wastes. The model is composed of system simulator and optimisation submodels. Conceptually...
Identification of waste management strategies and waste generation factors for thermal power plant sector wastes in Turkey Demir, Cansu; Yetiş, Ülkü; Ünlü, Kahraman (SAGE Publications, 2019-03-01) Thermal power plants are of great environmental importance in terms of the huge amounts of wastes that they produce. Although there are process-wise differences among these energy production systems, they all depend on the logic of burning out a fuel and obtaining thermal energy to rotate the turbines. Depending on the process modification and the type of fuel burned, the wastes produced in each step of the overall process may change. In this study, the most expected process and non-process wastes stemming ...
The effects of aquifer heterogeneity on the natural attenuation rates of chlorinated solvents Önkal, Başak; Ünlü, Kahraman; Department of Environmental Engineering (2005) Monitored natural attenuation has been particularly used at sites where petroleum hydrocarbons and chlorinated solvents have contaminated soil and groundwater. One of the important aspects of the methodology that has been recognized recently is that the mass removal rates, the most important parameter to determine effectiveness of the methodology, is controlled by the groundwater flow regime and the aquifer heterogeneity. Considering this recognition, the primary objective of this study is to quantitatively...
Modeling natural attenuation of petroleum hydrocarbons (btex) in heterogeneous aquifers Uçankuş, Tuğba; Ünlü, Kahraman; Department of Environmental Engineering (2005) Natural Attenuation can be an effective cleanup option for remediation of Groundwater contamination by BTEX. One of the important aspects of the methodology that has been recognized recently is that mass removal rates, the most important parameters used to determine effectiveness of the methodology, is controlled by groundwater flow regime, which to a large extent controlled by aquifer heterogeneity. Considering this recognition, the primary objective of this research is to quantitatively describe the relat...

Citation Formats

M. Kavruk, “Development of acetylcholinesterase biosensor for the detection of pesticides,” M.S. - Master of Science, Middle East Technical University, 2010.