Measuring Concentration of Heavy Metals in Waste Water Using Biosensor

Heydarian Dolatabadi, Ehsan | 2021

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 54631 (06)
  4. University: Sharif University of Technology
  5. Department: Chemical and Petroleum Engineering
  6. Advisor(s): Alemzadeh, Iran; Kalantarian, Asadollah
  7. Abstract:
  8. Wastewater, especially with heavy metal contamination, is a global environmental concern. Numerous techniques have been tested for online controlling and monitoring the concentration of heavy metal ions; yet, there are many challenges in performing these techniques. Biosensor is cheap, easily available, simple, fast, selective, sensitive, and repeatable so it is an excellent alternative for the detection and quantification of hazardous particles in the wastewater. In this study, a Nano biosensor with high detection of copper ions has been fabricated. PEDOT:PSS as a highly conductive polymer is coupled with gold nanoparticles to modify the surface of graphite electrode and results in higher sensitivity of the biosensor. The urease enzyme is the bioreceptor due to its inactivation in the presence of copper ions. FTIR and XRD tests were used to determine the bindings and functional groups of the polymer and nanoparticles. SEM test also depicted the morphology of the materials. Electrochemical characterization of the biosensor has been examined via two methods. Cyclic voltammetry and square wave voltammetry have been applied for every step of the study and different concentrations of copper ions as analytes. Optimization of response times showed that in 20 minutes, the maximum current response was achieved. Optimization of urea concentration and determination of kinetic parameter for enzymatic reaction has been carried out. By using Linweaver-Burk equation, sensitivity is 1.03×10-5 A. mM−1cm−2, Km=2.3 mM and Imax=1.37×10-5 A.cm-2. The detection limit concentration for this study is 0.093 µM.
  9. Keywords:
  10. Electrochemical Biosensors ; Urease ; Copper (II) Ion ; Gold Nanoparticle ; Biosensor ; Conductive Polymer ; PEDOT:PSS Conductive Polymer

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