Determination of Cloxacillin Residues using Design and Development of theElectrochemical Nanosensor based on Molecular Imprinted Polymer

Cloxacillin is an antibiotic useful for the treatment of a number of bacterial infections. It issemisynthetic and in the same class as penicillin [1]. Numerous Methods have been described fordetermination of Cloxacillin in food samples by Reversed-Phase High-Performance LiquidChromatography, FT-NIR spectroscopy and electrochemistry. Electrochemical analysis is moreattractive due to its simplicity, high sensitivity, fast response and relatively low cost [2]. On theother hand, molecularly imprinted polymers (MIPs) are tailor made materials with selectiverecognition properties toward a chosen guest molecule or related compounds similar to thatdisplayed by antibodies but without their experimental restrictions. These materials are preparedby the polymerization of a suitable monomer and a cross-linker agent in the presence of atemplate molecule [3]. Since, the application of electropolymerization for synthesis of MIP todetermination of cloxacillin residues in milk and animal tissue has not previously been reported.The aim of this work is development a procedure for separation and determination of Cloxacillinin dairy products based on electropolymerization of aniline layer on carbon ceramic electrode forcreation of MIP. Firstly, a multiwall carbon nanotube modified carbon ceramic composite wasprepared via sol gel. Next, presented composite was prepared into carbon ceramic electrode. Thesurface electrodes were coated with electropolymerization by a layer of molecular imprintedpolymer from polyaniline. Electropolymerization was preformed out in presence of Cloxacillinthrough applying potential in range of -0.2 to 1.1 V, at scan 6 cycles. The specialty site forCloxacillin was created in surface after extraction of Cloxacillin inside polymeric matrix. The morphology of electrode coated with molecular imprinted polymer was studied by scanningelectronic microscopy (Fig 1). Separation and determination of accumulated Cloxacillin onsurface electrode was optimized by changing parameters include pH solution, accumulation timeand temperature. The high anodic signal was obtained when presented nanosensor was allocatedin solution include 1.0 mM Cloxacillin and 0.1 M phosphate buffer with pH= 3.8 and 35 °C for95 min.The electrochemical behavior of proposed sensor was evaluated in different concentration ofCloxacillin, which their DPVs depicted in Fig 2 and its linear range and detection limit obtained120 – 600 nM and 48.0 nM, respectively.