Dense Layer of Bacteriophages Ordered in Alternating Electric Field and Immobilized by Surface Chemical Modification as Sensing Element for Bacteria Detection.

Faster and more sensitive environmental monitoring should be developed to face the worldwide problem of bacterial infections. To remedy this issue, we demonstrate a bacteria-sensing element that utilizes dense and ordered layers of bacteriophages specific to the given bacteria strain. We combine (1) the chemical modification of a surface to increase the surface coverage of bacteriophages (2) with an alternating electric field to greatly increase the number of properly oriented bacteriophages at the surface. Usually, in sensing elements, a random orientation of bacteriophages results in steric hindrance, which results in no more than a few percent of all receptors being available. An increased number of properly ordered phages results in the optimal performance of phage receptors, manifesting in up to a 64-fold increase in sensitivity and a limit of detection as low as 100 CFU mL-1. Our sensing elements can be applied for selective, sensitive, and fast (15 min) bacterial detection. A well-studied pair T4 bacteriophage-bacteria Escherichia coli, was used as a model; however, the method could be adapted to prepare bacteriophage-based sensors for detection of a variety of bacterial strains.