AVS 60th International Symposium and Exhibition
    Biomaterial Interfaces Wednesday Sessions
       Session BI+AI+AS+BA+IA+NL+NS+SP-WeA

Paper BI+AI+AS+BA+IA+NL+NS+SP-WeA2
Imaging Hydrated Schewanella p. Biofilm in a Microfluidic Reactor by ToF-SIMS

Wednesday, October 30, 2013, 2:20 pm, Room 201 B

Session: Characterization of Biointerfaces
Presenter: X.Y. Yu, Pacific Northwest National Laboratory
Authors: X.Y. Yu, Pacific Northwest National Laboratory
M. Marshall, Pacific Northwest National Laboratory
B. Liu, Pacific Northwest National Laboratory
Z. Zhu, Pacific Northwest National Laboratory
L. Yang, Pacific Northwest National Laboratory
E. Hill, Pacific Northwest National Laboratory
S. Belchik, Pacific Northwest National Laboratory
Correspondent: Click to Email
We recently developed a microfluidic interface that enables direct probing of liquid surface in vacuum using ToF-SIMS and SEM. The device contains a 100 nm thick silicon nitride (SiN) membrane as the detection area (1.5 ´ 1.5 mm2) and the microchannels fabricated from polydimethylsiloxane (PDMS) using soft lithography. The unique aspect of our approach is that the detection window is an aperture of 2-3 m m diameter, which allows direct detection of the liquid surface and use surface tension to hold the liquid within the aperture. Its application in ToF-SIMS as an analytical tool was evaluated. In this paper, we present new results of using the microfluidic flow cell to grow Schewanella p. biofilm and characterize the biofilm subsequently using ToF-SIMS in the hydrated environment. Depth profiling was used to drill through the SiN membrane and the biofilm grown on the substrate. A controlled media sample was used to compare with the wet biofilm sample. In addition, dry samples deposited on clean silicon wafer were studied to show the difference between wet and dry samples. Multivariate statistical analysis including Principle Component Analysis was used to investigate observations. Our results indicate that imaging biofilm in the hydrated environment using ToF-SIMS is possible using the unique microfluidic device for the first time. Moreover, characteristic biofilm fragments were observed in the wet sample than in dry sample, illustrating the advantage of imaging biofilm in the hydrated state.