title: Aptamer-based sensing for thrombin in red region via fluorescence resonant energy transfer between NaYF₄:Yb,Er upconversion nanoparticles and gold nanorods.
abstract: In this work, we design a FRET system for sensitive and selective determination of thrombin in red region, in which NaYF₄:Yb,Er upconversion nanoparticles (UCNPs) act as donor and gold nanorods (Au NRs) act as acceptor. NaYF₄:Yb,Er UCNPs with a strong emission at 661 nm were successfully synthesized by tuning the doped ions ratio. Carboxyl-functionalized NaYF₄:Yb,Er UCNPs and Au NRs were then prepared and conjugated with the thrombin aptamers, respectively. The fluorescence emission band of NaYF₄:Yb,Er UCNPs (λ(max)=661 nm) highly overlaps with the absorption band of Au NRs(λ(max)=666 nm), which benefits from the large tunability of the spectrum band of Au NRs. A FRET system was then formed when thrombin was added to the mixture of NaYF₄:Yb,Er UCNPs and Au NRs, which were both modified thrombin aptamers. The fluorescence quenching efficiency of NaYF₄:Yb,Er UCNPs was increased in a thrombin concentration-dependent manner, which built the principle of thrombin quantification. The linear range was 2.5-90 nM in an aqueous buffer, and 3.75-112.5 nM in spiked human serum samples for thrombin. It also demonstrates a high selectivity to other biological species due to the specific binding. The measurement of thrombin in human plasma is satisfying, suggesting that the FRET system is of practical value in a complex biological sample matrix in red region.
authors: Anhui Key Laboratory of Chemo-Biosensing, Key Laboratory of Functional Molecular Solids, Ministry of Education, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, PR China.
authors: Hongqi
authors: H
authors: Chen
authors: Fei
authors: F
authors: Yuan
authors: Shaozhen
authors: S
authors: Wang
authors: Juan
authors: J
authors: Xu
authors: Yiyan
authors: Y
authors: Zhang
authors: Lun
authors: L
authors: Wang
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D004871:Erbium / Q000737:chemistry*; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D005459:Fluorides / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D006801:Humans; D053758:Nanoparticles / Q000737:chemistry*; D043942:Nanotubes / Q000737:chemistry; D012680:Sensitivity and Specificity; D013917:Thrombin / Q000032:analysis*; D015018:Ytterbium / Q000737:chemistry*; D015019:Yttrium / Q000737:chemistry*
chemical_list: D052157:Aptamers, Nucleotide; C525362:sodium yttriumtetrafluoride; C081676:thrombin aptamer; D015019:Yttrium; D006046:Gold; D004871:Erbium; D013917:Thrombin; D015018:Ytterbium; D005459:Fluorides