利用（1）H NMR 光谱法测定纳米颗粒粒径。

Nanoparticle size determination by (1)H NMR spectroscopy.

机构信息

Instituto Regional de Investigación Científica Aplicada (IRICA) and Departamento de Química Orgánica, Facultad de Química, Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain.

出版信息

J Am Chem Soc. 2009 Oct 21;131(41):14634-5. doi: 10.1021/ja9065442.

DOI:10.1021/ja9065442

PMID:19785420

Abstract

High-resolution solution (1)H NMR spectroscopy has been used to characterize the size of Pd dendrimer-encapsulated nanoparticles (DENs). The Pd nanoparticles measured by this technique contain 55, 147, 200, or 250 atoms, and they are encapsulated within sixth-generation, hydroxyl-terminated poly(amidoamine) PAMAM dendrimers (G6-OH). Detailed analysis of the NMR data shows that signals arising from the innermost protons of G6-OH(Pd(n)) decrease significantly as the size of the encapsulated nanoparticles increase. A mathematical correlation between this decrease in the integral value and the theoretical number of Pd atoms in the nanoparticle is extracted. It enables the elucidation of the size of Pd DENs by (1)H NMR spectroscopy. NMR pulse-field gradient spin-echo experiments demonstrate that G6-OH with and without DENs have identical hydrodynamic radii, which excludes the presence of dendrimer/nanoparticle aggregates.

摘要

高分辨率溶液（1）H NMR 光谱已被用于表征钯树状大分子包裹纳米粒子（DENs）的尺寸。通过该技术测量的钯纳米粒子包含 55、147、200 或 250 个原子，它们被包裹在第六代、羟基末端的聚（酰胺-胺）PAMAM 树状大分子（G6-OH）内。对 NMR 数据的详细分析表明，随着包裹的纳米粒子尺寸的增加，来自 G6-OH（Pd(n)）的最内层质子的信号显著降低。从该积分值的减少中提取出与纳米粒子中钯原子理论数量之间的数学相关性。它通过（1）H NMR 光谱阐明了钯 DENs 的尺寸。NMR 脉冲场梯度自旋回波实验表明，具有和不具有 DENs 的 G6-OH 具有相同的流体力学半径，这排除了树状大分子/纳米粒子聚集体的存在。