最近最好的2019中文,最好看免费中文,最好免费观看高清在线,中文字幕在线观看,中文字幕2019年最好看电视剧,最好看的免费观看高清视频,最好看的电影2019中文字幕,最好看的2019年中文视频,最好看的MV中文字幕国语电影,最好看的中文字幕国语电视剧,最好看的2018国语在线,最好看免费中文在线看电视剧网站

Enhanced near-infrared photoacoustic imaging of silica-coated rare-earth doped nanoparticles

作者： Yang Sheng^{a, f}, Lun-De Liao^{b, c}, Aishwarya Bandla^{c, d}, Yu-Hang Liu^{c, e}, Jun Yuan^c, Nitish Thakor^{c, d, e}, Mei Chee Tan^a

^a Engineering Product Development, Singapore University of Technology and Design, 8 Somapah Road, Singapore 487372, Singapore

^b Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, 35 Keyan Rd., Zhunan Town, Miaoli County 35053, Taiwan, ROC

^c Singapore Institute for Neurotechnology (SINAPSE), National University of Singapore, 28 Medical Drive, #05-COR, Singapore 117456, Singapore

^d Department of Biomedical Engineering, National University of Singapore, 21 Lower Kent Ridge Rd, Singapore 119077, Singapore

^e Department of Electrical and Computer Engineering, National University of Singapore, 21 Lower Kent Ridge Rd, Singapore 119077, Singapore

^f School of Materials Science and Engineering, Changzhou University, Changzhou, Jiangsu 213164, PR China

摘要：Near-infrared photoacoustic (PA) imaging is an emerging diagnostic technology that utilizes the tissue transparent window to achieve improved contrast and spatial resolution for deep tissue imaging. In this study, we investigated the enhancement effect of the SiO2 shell on the PA property of our core/shell rare-earth nanoparticles (REs) consisting of an active rare-earth doped core of NaYF4:Yb,Er (REDNPs) and an undoped NaYF4 shell. We observed that the PA signal amplitude increased with SiO2 shell thickness. Although the SiO2 shell caused an observed decrease in the integrated fluorescence intensity due to the dilution effect, fluorescence quenching of the rare earth emitting ions within the REDNPs cores was successfully prevented by the undoped NaYF4 shell. Therefore, our multilayer structure consisting of an active core with successive functional layers was demonstrated to be an effective design for dual-modal fluorescence and PA imaging probes with improved PA property. The result from this work addresses a critical need for the development of dual-modal contrast agent that advances deep tissue imaging with high resolution and signal-to-noise ratio.