Polypeptide-mediated switchable microarray of bacteria.

This paper describes a feasible solution for the bacterial cell death and contamination from cell division that occurs in microfluidic applications. The method adopts a smart thermoresponsive surface, highly resolved micropatterns, and surface-functionalized bacteria tagged with thermoresponsive molecules. We developed a method for controllable bacterial attachment and detachment using an elastin-like polypeptide (ELP). To create a smart surface with switchable properties, the surface of a glass substrate was conjugated with thermoresponsive ELP molecules. The attachment of bacterial cells to the ELP surface was induced by the hydrophobic affinity of the ELPs on the glass surface to tagged ELPs on the bacterial surface. A cell-repellent polymer was micropatterned to create a highly resolved space for specific bacterial adhesion. Reversible bacterial attachment and detachment was achieved by controlling the thermoresponsive phase transition of ELP molecules. Five different types of bacteria were successfully conjugated with ELPs and arrayed on the surface. The viability of the bacteria that had attached to the surface was evaluated by determining colony forming units of released bacteria on an agar plate.