Related Experiment Video
Updated: Dec 31, 2025

Synthesis of Ligand-free CdS Nanoparticles within a Sulfur Copolymer Matrix
Published on: May 1, 2016
Emission Spectral Properties of Cadmium Sulfide Nanoparticles with Multiphoton Excitation
Joseph R Lakowicz1, Ignacy Gryczynski1, Gregorz Piszczek1
1Department of Biochemistry and Molecular Biology, Center for Fluorescence Spectroscopy, University of Maryland School of Medicine, 725 West Lombard Street, Baltimore, Maryland 21201.
Abstract:
We describe the luminescence spectral properties of CdS nanoparticles with multiphoton excitation. Three types of CdS nanoparticles were examined which were a CdS/dendrimer composite which displays high anisotropy, Cd2+-enriched nanoparticles which display two emission maxima, and polyphosphate-stabilized nanoparticles which display long wavelength emission. Illumination with long wavelengths near 700-790 nm resulted in two-photon excitation. Essentially the same emission spectra and intensity decays were observed with one-photon and two-photon excitation. Comparison with fluorescein indicates the NPs display large two-photon cross sections near 100 GM. The CdS/dendrimer and Cd2+-enriched CdS nanoparticles displayed large anisotropy values with two-photon excitation, substantially larger than with one-photon excitation. It appears that semiconductor nanoparticles are comparable to organic fluorophores which display the same spectral properties with one-photon and two-photon excitation.
Related Concept Videos
Atomic Emission Spectroscopy: Overview
Molecular Spectroscopy: Absorption and Emission
Atomic Emission Spectroscopy: Instrumentation

