Light induced DEP for immobilizing and orienting Escherichia coli bacteria. (January 2016)

• Record Type: Journal Article
• Authors: Miccio, Lisa; Marchesano, Valentina; Mugnano, Martina; Grilli, Simonetta; Ferraro, Pietro
• Is Part Of: Optics and lasers in engineering. Volume 76(2016)
• Page Start: 34
• Page End: 39
• Publication Date: 2016-01
• Subjects: Photorefractive effect -- Lithium Niobate -- Dielectrophoresis -- Bacteria patterning; Lasers in engineering -- Periodicals; Optical measurements -- Periodicals; Optics -- Periodicals; Lasers en ingénierie -- Périodiques; Mesures optiques -- Périodiques; Optique -- Périodiques; 621.36605
• DOI: 10.1016/j.optlaseng.2015.03.025
• Languages: English
• ISSNs: 0143-8166

Abstract

Abstract: Manipulating bacteria and understanding their behavior when interacting with different substrates are of fundamental importance for patterning, detection, and any other topics related to health-care, food-enterprise, etc. Here, we adopt an innovative dielectrophoretic (DEP) approach based on electrode-free DEP for investigating smart but simple strategies for immobilization and orientation of bacteria. Escherichia coli DH5-alpha strain has been selected as subject of the study. The light induced DEP is achieved through ferroelectric iron-doped lithium niobate crystals used as substrates. Due to the photorefractive (PR) property of such material, suitable light patterns allow writing spatial-charges-distribution inside its volume and the resultant electric fields are able to immobilize E. coli on the surface. The experiments showed that, after laser irradiation, about 80% of bacteria is blocked and oriented along a particular direction on the crystals within an area of few square centimeters. The investigation presented here could open the way for detection or patterning applications based on a new driving mechanism. Future perspectives also include the possibility to actively switch by light the DEP forces, through the writing/erasing characteristic of PR fields, to dynamically control biofilm spatial structure and arrangement. Highlights: Light induced DEP allows to immobilize E. coli . Lithium Niobate is funcionalized to trap bacteria cell on its surface. Manipulation of bacteria at large scale is demonstrated.