PEGylated Au-core-Ag-shell Nanorods as Optical Coherence Tomography Signal Nanoamplifiers

Optimizing contrast enhancement in optical coherence tomography (OCT) is essential for producing specific image signals and realizing its potential use in various biomedical imaging fields besides ophthalmology and cardiology. Using nanoparticles as selective signal nanoamplifiers will be helpful to highlight the lesion sites and identify cancerous changes that are difficult to diagnose currently. In this study, a quantitatively detailed analysis on the improvement of contrast enhancement and penetration depth of Au-core-Ag-shell nanorods (Au@Ag NRs) as OCT contrast agent was performed. The average A-scan data of the tissue was extracted and investigated. The signal to noise ratio (SNR) and relative 1/e light penetration depth were also calculated. Our measurements revealed that, after intravenous delivery, the visibility of the tumor site was most obvious when treated with Au@Ag NRs. And the maximum value of 1/e penetration depth of Au@Ag NRs grew by 25 % when compared to that of gold nanorods (Au NRs).National Basic Research Program of China [2011CB707504, 2010CB933903]; National Natural Science Foundation of China [81171377]SCI(E)ARTICLEzhoucq@sjtu.edu.cn61381-13891