Rapid detection of pathogens using antibody-coated microbeads with bioluminescence in microfluidic chips

Abstract

Detection of pathogens was demonstrated in a polydimethylsiloxane (PDMS)/glass microfluidic chip with which microbead-based immunoseparation platform and the bioluminescence technology were integrated. Escherichia coli (E. coli) O157:H7 was used as the model bacteria. The microchamber in microfluidic chip was filled with glass beads coated with antibodies which could capture specific organism, and the capture efficiency of the chip for the bacteria was about 91.75% approximately 95.62%. Then the concentration of bacteria was determined by detecting adenosine triphosphate (ATP) employing bioluminescence reaction of firefly luciferin-lucifera-ATP on chip. The method allowed reliable detection of E. coli O157:H7 concentrations from 3.2 x 10(1) cfu/microL to 3.2 x 10(5) cfu/microL within 20 min. This research demonstrated excellent reproducibility, stability, and specificity, and could accurately detect the pathogenic bacteria in food samples. The microfluidic chip and the equipments used in this method are easy to miniaturize, thus the method has great potential to be developed to a portable device for rapid detection of pathogens.

On-chip sample preparations for Point-of-Care cellular analysis of blood

“…A striking advantage is that the reversibly crosslinked alginate can be dissolved to release captured cells for further analysis. Microbeads are another carrier for antibody immobilization: a group of densely packed micobeads in a microchannel was able to capture E. coli with excellent efficiency from 91−95 % [87]. beads for E. coli capture.…”

“…The thickness step of the channel ensures monolayer formation and prevents washing away of beads. i) copyright 2007 Nature publishing [80]; ii) copyright 2010 American Chemistry Society [82]; iii) copyright 2010 Springer [87].…”

Miniaturized Detection Systems

“…Microfluidic chips with antibody-coated microbeads inside the microchannels overcome the potential limitations of the low surface area of planar microchannels, and have been applied for the immunoseparation of E. coli. 59 A flow-through immunomagnetic separation (IMS) for Cryptosporidium and…”

Microfluidic concentration of bacteria by on-chip electrophoresis

“…Antibody-coated particles have been used to selectively bind to the target species. These particles are trapped in microchannels by physical barrieres 9 or magnetic fields. [10][11][12] The capture efficiency strongly depends on the quality of the coatings and proper mixing of particles and analytes.…”