|Aggregation kinetics of gold-DNA (Au-DNA) nanoparticles in aquatic environments
|Jiang, Yi (CEE)
Hong Kong Polytechnic University -- Dissertations
|Department of Civil and Environmental Engineering
|v, 41 pages : color illustrations
|Recently, gold-DNA nanoparticles (Au-DNA) exhibits application potentials in sensing, biomedical, and environmental fields, likely leading to release of such nanoparticles into environment with unclear impact on the ecosystem. To better predict the environmental fate of Au-DNA nanoparticles, a systematical investigation of their colloidal stability becomes a necessity. In this research, we synthesized gold nanoparticles functionalized by different length scales (15 - 40 nucleotides) of DNA (Au-DNA) to investigate their aggregation behaviors in typical aqueous environments. The determination of the critical coagulation concentrations (CCCs) of Au-DNA nanoparticles under various electrolytes background (NaCl, CaCl2 and MgCl2), respectively was accomplished by Time-resolved dynamic light scattering (TR-DLS). Results showed that functionalization of DNA onto gold nanoparticles significantly enhanced their colloidal stability compared to their precursive form (citrate-stabilized gold nanoparticles). Aggregation behavior of tested Au-DNA nanoparticles is affected by ionic strength, cation types, and DNA length. By analyzing the impacts of electrolytes and DNA length, it can be reasonably assumed that the aggregation of Au-DNA nanoparticles is not only affected by van der Waals attraction and electrostatic repulsion, but also steric hindrance. Furthermore, a representative natural organic matter (NOM), Suwannee River Humic Acid, was introduced to observe the impact of NOM on aggregation behavior of Au-DNA nanoparticles. Au-DNA nanoparticles displayed a further strengthened colloidal stability in the presence of SRHA, which might be due to the adsorption of humic substances onto Au-DNA nanoparticles, resulting in the increase of steric stabilization.
|All rights reserved
Files in This Item:
|For All Users (off-campus access for PolyU Staff & Students only)
As a bona fide Library user, I declare that:
- I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
- I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
- I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.
By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.
Please use this identifier to cite or link to this item: