期刊
APPLIED SPECTROSCOPY
卷 61, 期 11, 页码 1191-1201出版社
SAGE PUBLICATIONS INC
DOI: 10.1366/000370207782597175
关键词
laser; photothermal effects; thermal lens; gold nanoparticles; threshold sensitivity
资金
- NIBIB NIH HHS [EB 00873, EB 005123] Funding Source: Medline
An approach for mode-mismatched two-beam (pump-probe) photothermal lens detection of multipoint light-absorbing targets in solution (e.g., gold nanoparticles) is developed for continuous-wave intensitymodulated laser-excitation mode. A description of the blooming of the thermooptical element (thermal lens) upon absorption of the excitation laser radiation is based on the summation of individual thermal waves from multiple heat sources. This description makes it possible to estimate the irregularities of the temperature (and, thus, the refractive index) profile for a discrete number of nanoparticles in the irradiated area and a change in the concentration and particle size parameters. Experimental results are in good agreement with theoretical dependences of the photothermal signal on nanoparticle size and concentration and excitation laser power. Calibration plots for particles from 2 to 250 nm show long linear ranges, limits of detection of gold nanoparticles at the level of hundreds of nanoparticles with the current setup, and the photothermallens sensitivity coefficient increases as a cubic function of particle size. Further improvements are discussed, including increasing the sensitivity thresholds up to one nanoparticle in the detected volume.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据