Tunable NIR-II emitting silver chalcogenide quantum dots using thio/selenourea precursors: preparation of an MRI/NIR-II multimodal imaging agent
作者:Karishma Bhardwaj、Sajan Pradhan、Siddhant Basel、Mitchell Clarke、Beatriz Brito、Surakcha Thapa、Pankaj Roy、Sukanya Borthakur、Lakshi Saikia、Amit Shankar、Graeme J. Stasiuk、Anand Pariyar、Sudarsan Tamang
DOI:10.1039/d0dt02974b
日期:——
Aqueous-stable, Cd- and Pb-free colloidal quantum dots with fluorescence properties in the second near-infrared region (NIR-II, 1000–1400) are highly desirable for non-invasive deep-tissue optical imaging and biosensing. The low band-gap semiconductor, silver chalcogenide, offers a non-toxic and stable alternative to existing Pd, As, Hg and Cd-based NIR-II colloidal quantum dots (QDs). We report facile access
在第二近红外区域(NIR-II,1000–1400)具有荧光特性的水稳定,无Cd和Pb的胶体量子点,对于非侵入式深层组织光学成像和生物传感是非常需要的。低带隙半导体硫属元素银提供了无毒且稳定的替代品,可替代现有的基于Pd,As,Hg和Cd的NIR-II胶体量子点(QD)。我们报告使用易于制备的硫代/硒脲前体及其类似物,利用Ag 2 X(X = S,Se)QD轻松访问NIR-II发射窗口。这些量子点的水相转移具有很高的荧光量子产率守恒性(保留率高达〜90%)和胶体稳定性。具有可调荧光和高T 1的双峰NIR-II / MRI造影剂通过分别将50个和120个一水合Gd(III)络合物接枝到两个分子上,制得了每个QD 408 mM -1 s -1(尺寸约为2.2 nm)和990 mM -1 s -1每个QD(尺寸约为4.2 nm)弛豫不同尺寸的Ag 2 S QD。纳米晶体的尺寸对于调节Gd有效载荷和弛豫性至关重要。