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Facile synthesis of Silicon quantum dot-Gadolinium: A potential fluorescent/T1-T2 multimodal imaging agent

Xiao, Fangnan, Xiao, Yue, Chen, Fangman, Liu, Xiaolin, Lin, Chentao, Chen, Jianxin, Wu, Yunkun
Talanta 2019 v.199 pp. 336-346
Danio rerio, biocompatibility, cell lines, cytotoxicity, dispersibility, fluorescence, image analysis, in vivo studies, magnetism, mice, neoplasm cells, quantum dots, silicon
Highly stable and multifunctional fluorescent quantum dots are particularly attractive in practical applications. Here, a new kind of ultra-small-sized silicon quantum dot-gadolinium (SiQD-Gd) was successfully fabricated by a newly-designed facile hydrothermal growth and chelating method. The obtained SiQD-Gd exhibited outstanding water dispersibility, stability and good fluorescent property with the quantum yield of 11.6%. SiQD-Gd displayed a low cytotoxicity in normal cell lines (HELF, HEK293F) and tumor cell lines (H1299, A549). Meanwhile, SiQD-Gd showed excellent magnetic resonance response with r1 relaxation rate of 10.5 mmol L−1·s−1 and r2 relaxation rate of 47.5 mmol L−1·s−1, which are 2.5 and 7.4 times enhanced comparing to that of the commercial MR agent Magnevist. In vivo studies showed significant contrast enhancement effect of its T1- and T2-weighted MR imaging. In addition, in vivo fluorescent imaging for mice and zebrafish indicated its potential applications in fluorescent tracking. Thus, the excellent multimodal imaging capacity and biocompatibility of SiQD-Gd make it a potential imaging agent for clinic applications.