Two-dimensional and three-dimensional dynamic imaging of live biofilms in a microchannel by time-of-flight secondary ion mass spectrometry

Xin Hua; Matthew J Marshall; Yijia Xiong; Xiang Ma; Yufan Zhou; Abigail E Tucker; Zihua Zhu; Songqin Liu; Xiao-Ying Yu

doi:10.1063/1.4919807

Two-dimensional and three-dimensional dynamic imaging of live biofilms in a microchannel by time-of-flight secondary ion mass spectrometry

Biomicrofluidics. 2015 May 5;9(3):031101. doi: 10.1063/1.4919807. eCollection 2015 May.

Authors

Xin Hua, Matthew J Marshall¹, Yijia Xiong², Xiang Ma³, Yufan Zhou⁴, Abigail E Tucker¹, Zihua Zhu⁴, Songqin Liu⁵, Xiao-Ying Yu⁶

Affiliations

¹ Biological Sciences Division, Pacific Northwest National Laboratory , Richland, Washington 99354, USA.
² College of Osteopathic Medicine of the Pacific-Northwest, Western University of Health Sciences , Lebanon, Oregon 97355, USA.
³ Material Sciences, Pacific Northwest National Laboratory , Richland, Washington 99354, USA.
⁴ W. R. Wiley Environmental Molecular Science Laboratory, Pacific Northwest National Laboratory , Richland, Washington 99354, USA.
⁵ School of Chemistry and Chemical Engineering, Southeast University , Nanjing, Jiangsu Province 211189, People's Republic of China.
⁶ Atmospheric Sciences and Global Climate Change Division, Pacific Northwest National Laboratory , Richland, Washington 99354, USA.

Abstract

A vacuum compatible microfluidic reactor, SALVI (System for Analysis at the Liquid Vacuum Interface), was employed for in situ chemical imaging of live biofilms using time-of-flight secondary ion mass spectrometry (ToF-SIMS). Depth profiling by sputtering materials in sequential layers resulted in live biofilm spatial chemical mapping. Two-dimensional (2D) images were reconstructed to report the first three-dimensional images of hydrated biofilm elucidating spatial and chemical heterogeneity. 2D image principal component analysis was conducted among biofilms at different locations in the microchannel. Our approach directly visualized spatial and chemical heterogeneity within the living biofilm by dynamic liquid ToF-SIMS.