A microfluidic device integrating plasmonic nanodevices for Raman spectroscopy analysis on trapped single living cells

[Display omitted] ► The microfluidic device integrates cell microfluidic traps and nanodevices. ► The used materials are compatible with Raman spectroscopy measurements. ► The device allows to trap single cells in correspondence of nanodevices. ► Raman measurements are performed for characterizing cell conditions. ► We propose an efficient method for label free single cell analysis. In this work we developed a microfluidic device integrating nanoplasmonic devices combined with fluidic trapping regions. The microfuidic traps allow to capture single cells in areas where plasmonic sensors are placed. In this way it is possible to perform Enhanced Raman analysis on the cell membranes. Moreover, by changing direction of the flux it is possible to change the orientation of the cell in the trap, so that it is possible to analyze different points of the membrane of the same cell. We shows an innovative procedure to fabricate and assembly the microfluidic device which combine photolithography, focused ion beam machining, and hybrid bonding between a polymer substrate and lid of Calcium fluoride. This procedure is compatible with the fabrication of the plasmonic sensors in close proximity of the microfluidic traps. Moreover, the use of Calcium fluoride as lid allows full compatibility with Raman measurements producing negligible Raman background signal and avoids Raman artifacts. Finally, we performed Raman analysis on cells to monitor their oxidative stress under particular non physiological conditions.