Aptamer-based sensing for thrombin in red region via fluorescence resonant energy transfer between NaYF4:Yb,Er upconversion nanoparticles and gold nanorods

作者：Chen, Hongqi; Yuan, Fei; Wang, Shaozhen; Xu, Juan; Zhang, YiYan; Wang, Lun^*

来源：Biosensors and Bioelectronics, 2013, 48: 19-25.

DOI：10.1016/j.bios.2013.03.083

• Upconversion nanoparticles
• Au nanorods
• FRET
• Thrombin
• Aptamer sensor

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 (lambda(max) = 661 nm) highly overlaps with the absorption band of Au NRs(lambda(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.

• 出版日期2013-10-15
• 单位安徽师范大学