Oriented T4 Bacteriophage Immobilization for E- coli Bacteria as A Potential Bioterrorism Agent Detection Based on Surface Plasmon Resonance Method

As a potential biological weapon, Escherichia coli (E. coli) is one of the most dangerous types of bacteria used in bioterrorism, which is responsible for many foodborne illnesses. In this study, a surface plasmon resonance biosensor (SPR) was designed to detect E. coli using oriented immobilization of T4 bacteriophage.

The surface of the gold disc was first modified with streptavidin. Then, the T4 bacteriophage was biotinylated. Optimization of biotin levels was performed using bacteriophage activity. After confirmation of bacteriophage biotinylation using the dynamic light scattering (DLS) method, T4 bacteriophage was oriented immobilized on the gold disk through the interactions between streptavidin and biotin.

The equilibrium dissociation constant (KD) was found to be 10-17, which showed the great affinity of bacteriophage to interact with E. coli. Using the designed biosensor, E. coli was detected in the concentration range of 101 to 109 bacteria per ml.

Label-free and fast detection of E. coli are the advantages of the proposed biosensor.