title: A microfluidic bioreactor with in situ SERS imaging for the study of controlled flow patterns of biofilm precursor materials.
abstract: A microfluidic bioreactor with an easy to fabricate nano-plasmonic surface is demonstrated for studies of biofilms and their precursor materials via Surface Enhanced Raman Spectroscopy (SERS). The system uses a novel design to induce sheath flow confinement of a sodium citrate biofilm precursor stream against the SERS imaging surface to measure spatial variations in the concentration profile. The unoptimised SERS enhancement was approximately 2.5 × 10(4), thereby improving data acquisition time, reducing laser power requirements and enabling a citrate detection limit of 0.1 mM, which was well below the concentrations used in biofilm nutrient solutions. The flow confinement was observed by both optical microscopy and SERS imaging with good complementarity. We demonstrate the new bioreactor by growing flow-templated biofilms on the microchannel wall. This work opens the way for in situ spectral imaging of biofilms and their biochemical environment under dynamic flow conditions.
authors.affiliation: Département de Chimie, Université Laval, 1045 Avenue de la Médecine, Québec, QC G1V 0A6, Canada. jesse.greener@chm.ulaval.ca.
authors.forename: François
authors.initials: F
authors.lastname: Paquet-Mercier
authors.forename: Nahid Babaei
authors.initials: NB
authors.lastname: Aznaveh
authors.forename: Muhammad
authors.initials: M
authors.lastname: Safdar
authors.forename: Jesse
authors.initials: J
authors.lastname: Greener
mesh_terms: D018441:Biofilms; D019149:Bioreactors; D002951:Citrates / Q000032:analysis / Q000737:chemistry; D057230:Limit of Detection; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods; D000077559:Sodium Citrate; D013057:Spectrum Analysis; D013059:Spectrum Analysis, Raman / Q000295:instrumentation* / Q000379:methods
chemical_list: D002951:Citrates; D000077559:Sodium Citrate