Investigation Of Oriented Immobilization Of Bacteriophage For Fabrication Of Free Label Biosensor

Abstract

One of the dangerous human pathogens is Escherichia coli (E. coli). It causes life-threatening difficulties such as bloody diarrhea and renal failure. The study and preparation of E. coli biosensors are very important and required for diagnostic laboratories. Therefore, we studied oriented immobilized E. coli bacteriophage for label-free biosensor of E. coli bacteria detection and oriented immobilized bacteriophage was investigated in many methods such as FESEM, DLS, UV-Vis spectroscopy, and electrochemistry. For oriented immobilization of phage on the electrode, it was necessary to optimize the concentration of biotin. So, the biotin concentration was optimized by plaque-forming a unit, which was 8.5 mg/ml biotin. The stages of bacteriophage immobilization on the electrode were studied with FESEM, DLS, and CVs. Also, the effect of pH changes on bacteriophage/Au electrodes were studied in a wide range and pH=7 was the candidate. E. coli bacteria were measured by LCR meter in the capacitance method. It detected E. coli in the wide concentration range from 4×10² to 1.4×10⁴ N/mL.  We prepared label-free, inexpensive, cheap, rapid, and renewable E. coli biosensors by immobilizing oriented bacteriophage on modified gold bacteriophage biosensors. It seems that this system has the ability to be used as a platform for other pathogens.