Silica-coated Ln3+-doped LaF3 nanoparticles as robust down- and upconverting biolabels
Silica-coated Ln3+-doped LaF3 nanoparticles as robust down- and upconverting biolabels
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DOI：
10.1002/chem.200600224
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发表时间：
2006-07-24
影响因子：
4.3
通讯作者：
van Veggel, Frank C. J. M.
中科院分区：
文献类型：
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作者：
Sivakumar, Sri;Diamente, Peter R.;van Veggel, Frank C. J. M.
本报告描述了近单分散（40纳米）、二氧化硅包覆的LaF₃:Ln(3+)纳米粒子的制备及其与异硫氰酸荧光素 - 亲和素（FITC = 异硫氰酸荧光素）的生物共轭。在LaF₃核中掺杂选定的发光Ln(3+)离子使粒子能够在可见光到近红外区域（λ = 450 - 1650纳米）显示一系列发射谱线。首先，使用Tb³⁺和Eu³⁺离子通过能量下转换过程分别产生绿色（λ = 541纳米）和红色（λ = 591和612纳米）发射。其次，使用Nd³⁺通过能量下转换过程在λ = 870、1070和1350纳米处产生发射谱线，Er³⁺通过能量下转换过程在λ = 1540纳米处产生发射谱线。此外，当与Yb³⁺共掺杂（λ(ex)= 980纳米）时，Er³⁺离子通过上转换过程产生绿色和红色发射，Tm³⁺离子在λ = 800纳米处产生发射。亲和素具有结合的荧光团（FITC）作为报告分子，其生物共轭是通过用3 - 氨丙基三甲氧基硅烷对二氧化硅粒子进行表面改性，然后与生物素 - N - 羟基琥珀酰亚胺活化酯反应形成酰胺键来实现的，从而赋予粒子生物活性。相对于未生物素化的二氧化硅粒子，FITC信号增加了25倍或更多，这表明FITC - 亲和素与二氧化硅粒子的非特异性结合极小。
The preparation of nearly monodisperse (40 nm), silica-coated LaF3:Ln(3+) nanoparticles and their bio-conjugation to FITC-avidin (FITC= fluorescein isothiocyanate) is described in this report. Doping of the LaF3 core with selected luminescent Ln(3+) ions allows the particles to display a range of emission lines from the visible to the near-infrared region (lambda= 450-1650 nm). First, the use of Tb3+ and Eu3+ ions resulted in green (lambda= 541 nm) and red (lambda = 591 and 612 nm) emissions, respectively, by energy downconversion processes. Second, the use of Nd3+ gave emission lines at lambda=870, 1070 and 1350 nm and Er 31 gave an emission line at lambda = 1540 nm by energy downconversion processes. Additionally, the Er 31 ions gave green and fed emissions and TM3+ ions gave an emission at = 800 nm by upconversion processes when codoped with Yb3+ (lambda(ex)= 980 nm). Bioconjugation of avidin, which has a bound fluorophore (FITC) as the reporter, was carried out by means of surface modification of the silica particles with 3-aminopropyltrimethoxysilane, followed by reaction with the biotin-N-hydroxysuccinimide activated ester to form an amide bond, imparting biological activity to the particles. A 25-fold or better increase in the FITC signal relative to the non-biotinylated silica particles indicated that there is minimal nonspecific binding of FITC-avidin to the silica particles.