Sensitive molecular detection using fluorescence-enhancing core-shell nanoparticles

荧光纳米颗粒探针如量子点和染料掺杂的二氧化硅纳米颗粒（NPs）由于其更高的发光和增强的化学和生物物理稳定性而越来越多地用于生物分析化学中。特别地，染料掺杂的二氧化硅NP可以使用简单的溶胶-凝胶化学在水性介质中非常容易地制备。然后，这些发光NP可以用寡核苷酸、抗体等功能化，并用作各种分析物的光学标记。然而，在这些NP中使用的荧光团的量子效率由于自猝灭（即，在相邻荧光团之间发生的信号损失）而大大降低，并且这种现象限制了染料掺杂的NP中的有效荧光团浓度和可实现的检测灵敏度。

Fluorescent nanoparticle probes such as quantum dots and dye-doped silica nanoparticles (NPs) are used increasingly in bioanalytical chemistry, due to their higher luminescence and enhanced chemical and photophysical stability. Dye-doped silica NPs, in particular, can be prepared very easily in aqueous media using straightforward sol-gel chemistry. These luminescent NPs can then be functionalized with oligonucleotides, antibodies, etc. and used as optical markers for various analytes. However, the quantum efficiency of the fluorophores used in these NPs is strongly diminished by self-quenching (i.e. signal losses occurring between neighboring fluorophores) and this phenomenon limits the effective fluorophore concentration in dye-doped NPs and the achievable detection sensitivity.