Microscope-based label-free microfluidic cytometry.

A microscope-based label-free microfluidic cytometer capable of acquiring two dimensional light scatter patterns from single cells, pattern analysis of which determines cellular information such as cell size, orientation and inner nanostructure, was developed. Finite-difference time-domain numerical simulations compared favorably with experimental scatter patterns from micrometer-sized beads and cells. The device was capable of obtaining light scattering patterns from the smallest mature blood cells (platelets) and cord blood hematopoietic stem/progenitor cells 
(CD34 + cells) and myeloid precursor cells.

Thermo-kinetics study of laser-induced desorption of self-assembled monolayers from gold: case of laser micropatterning.

Laser-induced desorption of self-assembled monolayers (SAMs) from gold surfaces within context of the direct laser patterning methodology was investigated through combining results of a heat diffusion thermal model with desorption kinetics of alkanethiol SAMs. It was found that contrast plots of experimental scanning electron microscopy (SEM) images, which are correlated to surface coverage of SAMs desorbed after laser irradiation, agreed with the theoretically predicted surface composition of SAMs. The surface composition of SAM was then interpreted in terms of the wetting property of the resulting surface.

Direct patterning of self-assembled monolayers on gold using a laser beam.

The development of a methodology to manipulate surface properties of a self-assembled monolayer (SAM) of alkanethiol on a gold film using direct laser patterning is the objective of this paper. The present study demonstrates proof of the concept for the feasibility of laser patterning monolayers and outlines theoretical modeling of the process to predict the resulting feature size. This approach is unique in that it eliminates the need for photolithography, is noncontact, and can be extended to other systems such as SAMs on silicon wafers or potentially polymeric substrates.