Aggregation Control of Quantum Dots through Ion-Mediated Hydrogen Bonding Shielding

作者：Liu, Jianbo; Yang, Xiaohai; Wang, Kemin^*; He, Xiaoxiao; Wang, Qing; Huang, Jin; Liu, Yan

来源：ACS Nano, 2012, 6(6): 4973-4983.

DOI：10.1021/nn300517k

• disaggregation
• F- ions
• quantum dots
• hydrogen bonding
• nonspecific adsorption

Nanoparticle stabilization against detrimental aggregation is a critical parameter that needs to be well controlled. Herein, we present a facile and rapid ion-mediated dispersing technique that leads to hydrophilic aggregate-free quantum dots (QDs). Because of the shielding of the hydrogen bonds between cysteamine-capped QDs, the presence of F- ions disassembled the aggregates of QDs and afforded their high colloidal stability. The F- ions also greatly eliminated the nonspecific adsorption of the QDs on glass slides and cells. Unlike the conventional colloidal stabilized method that requires the use of any organic ligand and/or polymer for the passivation of the nanoparticle surface, the proposed approach adopts the small size and large diffusion coefficient of inorganic ions as dispersant, which offers the disaggregation a fast reaction dynamics and negligible influence on their intrinsic surface functional properties. Therefore, the ion-mediated dispersing strategy showed great potential in chemosensing and biomedical applications.

• 出版日期2012-6
• 单位湖南大学; 化学生物传感与计量学国家重点实验室