Bhuckory Shashi, Lahtinen Satu, Höysniemi Niina, Guo Jiajia, Qiu Xue, Soukka Tero, Hildebrandt Niko
Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France.
EMEA Clinical Service Operations, NAMSA, 38670 Chasse-sur-Rhône, France.
Nano Lett. 2023 Mar 22;23(6):2253-2261. doi: 10.1021/acs.nanolett.2c04899. Epub 2023 Feb 2.
Upconversion nanoparticles (UCNPs) have been frequently applied in Förster resonance energy transfer (FRET) bioanalysis. However, the understanding of how surface coatings, bioconjugation, and dye-surface distance influence FRET biosensing performance has not significantly advanced. Here, we investigated UCNP-to-dye FRET DNA-hybridization assays in HO and DO using ∼24 nm large NaYF:Yb,Er UCNPs coated with thin layers of silica (SiO) or poly(acrylic acid) (PAA). FRET resulted in strong distance-dependent PL intensity changes. However, the PL decay times were not significantly altered because of continuous Yb-to-Er energy migration during Er-to-dye FRET. Direct bioconjugation of DNA to the thin PAA coating combined with the closest possible dye-surface distance resulted in optimal FRET performance with minor influence from competitive quenching by HO. The better comprehension of UCNP-to-dye FRET was successfully translated into a microRNA (miR-20a) FRET assay with a limit of detection of 100 fmol in a 80 μL sample volume.
上转换纳米粒子（UCNPs）已被频繁应用于荧光共振能量转移（FRET）生物分析中。然而，对于表面涂层、生物共轭以及染料与表面的距离如何影响FRET生物传感性能的理解尚未取得显著进展。在此，我们使用包裹有薄层二氧化硅（SiO）或聚丙烯酸（PAA）的约24 nm大的NaYF:Yb,Er UCNPs，研究了在水和重水中UCNP到染料的FRET DNA杂交分析。FRET导致了强烈的距离依赖性荧光强度变化。然而，由于在铒到染料的FRET过程中镱到铒的能量持续迁移，荧光衰减时间没有显著改变。将DNA直接与薄的PAA涂层进行生物共轭，并结合尽可能近的染料与表面距离，产生了最佳的FRET性能，且受水的竞争性猝灭影响较小。对上转换纳米粒子到染料的FRET的更好理解成功转化为一种微小RNA（miR - 20a）FRET分析方法，在80 μL样品体积中的检测限为100 fmol。
