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Analytica 2016
September 28-30, 2016
Volume 7, Issue 5(Suppl) J Anal Bioanal Tech 2016
ISSN: 2155-9872 JABT, an open access journal
conferenceseries .com
September 28-30, 2016 Orlando, USA
7th International Conference and Exhibition on
Analytical & Bioanalytical Techniques
J Anal Bioanal Tech 2016, 7:5(Suppl)
D2Dx-From diameter to diagnostics: Gold nanoparticle-enabled dynamic light scattering assay for
chemical and biological target detection and analysis
Tianyu Zheng
University of Central Florida, USA
Dynamic light scattering (DLS) is an analytical technique used routinely to measure the hydrodynamic sizes of particles
with diameters in the nanometer region. Gold nanoparticles are known for their exceptional light scattering properties.
By combining the strong light scattering property of gold nanoparticle probes with the size measurement capability of DLS, a
new technique named as D2Dx (from diameter to diagnostics) for chemical and biological target detection and analysis was
developed. Gold nanoparticles can be surface-modified with various chemical ligands, antibodies or other binding molecules
to form gold nanoparticle probes. The binding of chemical or biological target analytes with their specific gold nanoparticle
probes can lead to nanoparticle cluster formation, and subsequently, an average particle size increase of the assay solution.
Such particle size increases can be measured by DLS, and correlated to the quantity of the target analytes. D2Dx is a single-
step homogeneous solution assay, easy to perform, of low cost, and has excellent sensitivity and reproducibility. So far, this
technique has been applied successfully for quantitative detection and analysis of a wide range of chemical and biological
targets, including proteins, DNAs, viruses, carbohydrates, small chemicals, toxic metal ions, food and environmental toxins.
In this talk, I will explain the principle of D2Dx, give an overview on the application potentials of this technique in biomedical
research, food safety and environmental protection, and then present several specific examples of using D2Dx for protein
detection and analysis.
Environmental estrogens: An analytical challenge
Yuegang Zuo, Si Zhou, Yuejuan Lin and Yiwei Deng
1University of Massachusetts Dartmouth, USA
2University of Michigan-Dearborn, USA
Estrogenic compounds, particularly the synthetic estrogenic steroids-ethinyl estradiol (EE2) and mestranol (MeEE2) and
natural hormone steroids-estrone (E1), estradiol (E2) and estriol (E3), have attracted a great deal of scientific and public
attention during recent years due to their occurrence in surface waters and sewage treatment plant effluents and their potential
adverse effects on the development and reproduction of fish, wildlife and even human beings. In this presentation, we will
focus on our research on the occurrence, sources, and microbial and photochemical degradation of both synthetic and natural
estrogenic steroids in fresh and marine aquatic environments and their effects on public health during the past decade. To
face analytical challenges for determining trace amounts of estrogenic steroids in natural waters, GC-MS and HPLC analytical
methods have been developed.The developedmethods were applied to the water samples periodically collected fromwastewater
treatment plants, lakes, Acushnet River and Buzzards Bay. The interested compounds were detected in several of water samples
in nano to micro-gram per liter concentration range, can certainly cause fish feminization and may also contribute to the
observed declines in American lobster population in Buzzards Bay. Microbial and photochemical degradation of E1, E2, E3,
EE2 and MeEE2 have been also investigated in seawater as well as in waste, lake and river waters as a comparison. The microbial
degradation of synthetic steroid estrogens is extremely slow with a half-life of longer than 70 days in seawater. However, the
photo degradation of these compounds is much faster with a half-life of 17 hours for EE2 and 19 hours for MeEE2. Humic
and other dissolved organic substances significantly accelerate the sunlight-induced photo degradation of estrogenic steroids.
Transition metal Fe(III), nitrate and nitrite can further catalyze the photochemical decomposition of these steroids.