Probing the spatiotemporal response of individual intracellular proteins and multi-peptide complexes is
essential in understanding the integrated response of cells. Although dynamic information can be captured
using optical microscopy, most conventional spatial resolutions are limited to around 200 nm, which is
significantly greater than the size of molecules. One mode of microscopy that overcomes this resolution
limitation is the electron microscope, which enables in situ protein labeling and allows for single or
sub-nanometer resolution to be obtained. Transmission electron microscopy though is limited by the inability to
capture dynamic molecular responses. Here, we have demonstrated the ability to use quantum dots for both
modes of microscopy through a single labeling technology, which allows both dynamic and high resolution
visualization with optical and electron microscopy. We visualized core-shell CdSe/ZnS quantum dots within
<i>Dictyostelium discoideum</i> using both microscopy modes through a bacterial nutrient protocol, which enables
the quantum dots to enter living cells without the need of an artificial transporter system for assisted
internalization. Optical imaging was first used to visualize the spatiotemporal behavior of actin filaments using
phalloidin conjugated quantum dots. The same cells were then imaged using a transmission electron
microscope to examine the detailed intracellular distribution down to a single nanometer size scale. These
results have potential applications in a variety of areas including biophysics, cell motility, cancer metastasis,
and cell structure.
To fabricate the more complex structures, developing simplified methods will create greater utility for researchers.
Herein, we present a method to build three-dimensional structures through the optical method combined with
photoactivation chemistry and Al<sub>2</sub>O<sub>3</sub> nanopore membrane. This phase transition reaction in this material was initiated by
the UV-light energy from the fluorescent microscope. This method merges an optical approach along with phase shifting
chemical restructuring through the transition of the chemical from an aqueous to a solid phase. We also fabricated the
square three-dimensional microstructure based on this method. This method has potential applications in a variety of
fields, which include building three-dimensional complex structures such as microfluidics, lab-on-chip and small-scale
scaffolds for tissue engineering.