Preparation of molecular imprinting electrochemical sensors based on carbon nitride nanotube/polyoxometalate hybrid for lindane determination

Organochlorine compounds like gamma-lindane (γ-LND) are higly toxic and harmuful ubiquitous contaminants in the environment. In this thesis, new molecular imprinted electrocehemical sensors on polyoxometalate (POM, H3PW12O40)/carbon nitride nanotubes (C3N4 NTs) composite were prepared for γ-LND detection. Up to now, the traditional methods were developed for the determination of organochloro pesticides such as gas chromatography (GC), liquid chromatography-mass spectroscopy (LC-MS) and high performance liquid chromatography (HPLC). However, a long analysis time and costly instrumentations are needed on these methods. In addition, these methods require highly skilled personnel and elaborate sample preparation. Therefore, there is a need to develop more sensitive, economically viable and faster for the analysis of these pesticides. Especially, electroanalytical techniques based on nanomaterial are frequently used because of their various advantages such as selective and sensitive and stable response production. In this thesis study, the structures of C3N4 NTs and H3PW12O40/C3N4 NTs composite were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), x-ray photoelectron spectroscopy (XPS), fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Then, γ-LND imprinted electrodes were prepared in the presence of 100.0×10-3 M pyrrole containing 25.0×10-3 M γ-LND. The analytical results have revealed that 1.0×10-10 - 1.0×10-8 M and 2.0×10-11 M were found as linearity range and the detection limit (LOD). Finally, the imprinting electrochemical sensor was applied to orange juice samples having high recovery for γ-LND detection.