Revista de técnicas analíticas y bioanalíticas

Abstracto

Immobilization of P22 Bacteriophage Tailspike Protein on Si Surface for Optimized Salmonella Capture

Sarang Dutt, Jamshid Tanha, Stephane Evoy and Amit Singh

Bacteriophage based technology has gained interest in developing pathogen detection platforms for biosensing applications. In this study, P22 phage tail spike proteins (TSPs) have been immobilized on Si surfaces for optimized capture of host Salmonella enteric serovar Typhimurium. It was then demonstrated that roughening of the Si surface before the TSP immobilization improves the bacterial capture 2-fold compared to a flat Si surface. Coarse, medium, fine and superfine size ridges were patterned on the Si surface using block copolymer layer and plasma etching and each surface was functionalized by TSPs for bacterial capture. The capture density increased with decreasing size of the ridge until it reached an optimum for fine ridges; the capture density decreased when the surface ridges were superfine and deep. This method shows a 22-fold and 3-fold increase in bacterial capture density compared to a Cys- and a His6-tag based oriented TSP immobilization, respectively. Bovine serum albumin (BSA) was used as a surface protective layer to prevent non-specific binding of bacteria and E. coli cells were used as control to demonstrate the specificity of recognition. Negligible binding was observed for control bacteria in presence of TSPs and the host bacteria in the absence of TSP on the surfaces.