Nanophotonics 2015
Supplementary Material
Open Access
Yuchao Li, Hongbao Xin, Chang Cheng, Yao Zhang*, and Baojun Li*
Optical separation and controllable delivery of
cells from particle and cell mixture
1 Analysis of optical forces in
water, phosphate buffered
saline, and blood plasma
To analyze the effects of different surrounding solutions on
the optical force, numerical simulations based on finite element method (FEM) were carried out. In the simulations,
the 5 µm cells or 5 µm PMMA particles were suspended in
water, phosphate-buffered saline (PBS) and blood plasma
that were commonly used surrounding solutions for living cells. The refractive indices of water, PBS, and blood
plasma were set to be 1.330, 1.335 [1], and 1.350 [2], respectively, and the optical power of laser beam launched
into the fiber probe was 39 mW. The optical force F was
then calculated as a function of D A , as shown in Figure S2,
where D A is axial distance of the cell or particle to the fiber
probe tip. The results show that the optical force is decreased when the cells or particles are suspended in PBS
or blood plasma solution, of which the refractive indices
are slightly higher than water, but the differences are relatively small. The force is decreased by ~2% and ~5% in
PBS and blood plasma, respectively, compared with that
in water. Therefore, to maintain the same optical force for
the separation as that in water, the optical power needed
to be merely increased by 1–2 mW when applied in PBS and
blood plasma.
Figure S1: Optical microscope image of separation of human cancer cells and yeast cells with different sizes. Cells I, II and III are
separated into three chains.
Figure S2: Optical forces F on the 5 µm cells or PMMA particles in
water, PBS and blood plasma solutions as a function of distance
DA .
2 Optical separation of cells with
bigger size and internal
complexity
*Corresponding Author: Yao Zhang: State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275, China; Email:
[email protected]
*Corresponding Author: Baojun Li: State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275, China; Email:
[email protected]
Yuchao Li, Hongbao Xin, Chang Cheng: State Key Laboratory of
Optoelectronic Materials and Technologies, School of Physics and
Engineering, Sun Yat-Sen University, Guangzhou 510275, China
By launching a 980-nm laser beam into the ATF, human
cancer cells and yeast cells with different sizes were separated into three chains, as shown in Figure S1. The ~25-µm
cells (cell I), ~15-µm cells (cell II) and ~10-µm cells (cell III)
were separated with distances of L1 = 20.4 µm and L2 =
28.3 upµm. This experiment confirmed that the cells with
bigger size (about 10–30 µm) and internal complexity can
also be separated by the presented method.
© 2015 Baojun Li et al., licensee De Gruyter Open.
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License.
2 | Baojun Li et al.
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