[Analytical Chemistry] A facile droplet-chip-time-resolved ICPMS on-line system for determination of
Single cell analysis is a significant research field in recent years reflecting heterogeneity of cells in biological system. In this work, a facile droplet chip was fabricated and on-line combined with time-resolved inductively coupled plasma mass spectrometry (ICPMS) via a micro-flow nebulizer for the determination of zinc in single HepG2 cells. On the focusing geometric designed PDMS microfluidic chip, the aqueous cell suspension was ejected and divided by hexanol to generate droplets. The droplets encapsulated single cells remain intact during the transportation into ICP for subsequent detection. Under the optimized conditions, the frequency of droplet generation is 3-6×106 min-1, and the injected cell number is 2500 min-1, which can ensure the single cell encapsulation. ZnO nanoparticles (NPs) were used for the quantification of zinc in single cells, and the accuracy was validated by conventional acid digestion-ICPMS method. The ZnO NPs incubated HepG2 cells were analyzed as model samples, and the results exhibit the heterogeneity of HepG2 cells in the uptake/adsorption of ZnO NPs. The developed on-line droplet-chip-ICPMS analysis system achieves stable single cell encapsulation and has high throughput for single cell analysis. It has the potential in monitoring the content as well as distribution of trace elements/NPs at single cell level.
Han Wang, Beibei Chen, Man He, and Bin Hu Anal. Chem., Just Accepted Manuscript DOI: 10.1021/acs.analchem.7b00134 Publication Date (Web): April 11, 2017 Copyright © 2017 American Chemical Society