Methods for Fabricating Microarrays of Motile Bacteria

Abstract

Motile bacterial cell microarrays were fabricated by attaching Escherichia coli K-12 cells onto predesigned 16-mercaptohexadecanoic acid patterned microarrays, which were covalently functionalized with E. coli antibodies or poly-L-lysine. By utilizing 11-mercaptoundecyl-penta(ethylene glycol) or 11-mercapto-1-undecanol as passivating molecules, nonspecific binding of E. coli was significantly reduced. Microcontact printing and dip-pen nanolithography were used to prepare microarrays for bacterial adhesion, which was studied by optical fluorescence and atomic force microscopy. These data indicate that single motile E. coli can be attached to predesigned line or dot features and binding can occur via the cell body or the flagella of bacteria. Adherent bacteria are viable (remain alive and motile after adhesion to patterned surface features) for more than four hours. Individual motile bacterial cells can be placed onto predesigned surface features that are at least 1.3 microm in diameter or larger. The importance of controlling the adhesion of single bacterial cell to a surface is discussed with regard to biomotor design.

Immunoimmobilization of Living Salmonella for Fundamental Studies and Biosensor Applications

“…Thus, it is possible for bacteria to adhere to a positively charged substrate prepared by modifying the surface using positively charged polymers or silanes. Various bacteria have been attached to substrates decorated with polylysine (Rozhok et al 2006;Rozhok et al 2005), polyethyleneimmine (Razatos et al 1998), amino-terminated silanes (Arnoldi et al 1998), gelatin (Doktycz et al 2003) and alginate . However, unlike eukaryotic cells, bacterial cells are still very challenging to immobilize reliably and reproducibly under their physiological conditions using positively charged polymers.…”

“…However, previous work using antibodies against whole bacterial cells often resulted in low immobilization efficiency (Premkumar et al 2001;Rozhok et al 2005). A general guideline for antibody selection is to use antibodies targeting antigens on the surface of the bacterium (the outer membrane of Gram-negative and the peptidoglycan layer of Gram-positive bacteria).…”

Building communities one bacterium at a time

“…These communities require techniques for controlling their spatial organization (e.g., geometry and distance) to achieve stability. One way to impose this organization is by using a microfluidic device (16,17), such as the system described by Kim et al (7), or other techniques for controlling the position of bacteria on surfaces (18,19).…”

Fabrication of nanocomposites and hybrid materials using microbial biotemplates

“…Besides, bacterial immobilization can also take place due to the specific antigen-antibody interaction. The fabrication of microarrays of motile E. coli on gold surfaces was achieved by that method [27]. Similarly, Salmonella enterica serovar typhimurium has also been successfully patterned on substrate through specific interaction of bacterial CFA/I fimbriae with corresponding antibody [28].…”

“…This concept can be further developed to design and fabricate microdevices based [25][26][27][29][30][31] on bacterial cells to study the interactions between cells and their surroundings, biosensing and biodetection, smallmolecule screening, single-cell manipulation and analysis, biomaterials fabrication, and bioenergy synthesis [29]. For example, living bacteria were inserted into a microwell array formed at one end of an imaging fiber bundle, to be used as a biosensor for genotoxin monitoring.…”