Molecular Recognition Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792, South Korea; Department of Material Science and Engineering, Yonsei University, Seodaemun-gu, Seoul, 120-749, South Korea.
Sensor System Research Center, KIST, Seoul, 02792, South Korea.
Biosens Bioelectron. 2020 Feb 15;150:111921. doi: 10.1016/j.bios.2019.111921. Epub 2019 Nov 26.
Upconversion nanoparticles (UCNPs) are promising materials for biological applications based on luminescence resonance energy transfer (LRET). In contrast to classical RET donors such as quantum dots, gold nanoparticles, UCNPs can emit near-infrared (NIR) upon the NIR irradiation, which provides enhanced signal-to-noise due to strong penetration and low autofluorescence in the NIR region known as the diagnostic window. Here we report the first efficient NIR-to-NIR signal-based LRET system for the detection of progesterone, chosen as a proof-of-concept target, via homogeneous competitive immunoassay. To enhance the efficiency of LRET, we constructed inert-core/active-shell/inert-ultrathin shell UCNPs (NaYF@NaYF:Yb,Tm@NaYF) as an LRET donor and a compact progesterone/horseradish peroxidase/IRdyeQC-1 (P-HRP-dyes) complex as an LRET acceptor. The designed donor and acceptor showed significantly improved LRET efficiencies (95% and 85% for donor and acceptor, respectively) compared with conventional donor and acceptor (70% and 50%, respectively). Using the developed NIR-to-NIR LRET system, progesterone was successfully detected with a background-free signal and low limit of detection (1.36 pg/ml in ten-fold diluted human serum). We believe that the efficient NIR-to-NIR signal-based LRET system developed here has potential as a simple probe for homogeneous competitive immunoassay, with the ability to rapidly detect biomarkers.
上转换纳米粒子（UCNPs）是基于荧光共振能量转移（LRET）的生物应用的有前途的材料。与经典的 RET 供体（如量子点、金纳米粒子）相比，UCNPs 在近红外（NIR）照射下可以发射近红外光，由于在被称为诊断窗口的近红外区域具有较强的穿透性和低自发荧光，因此可以提供增强的信号噪声比。在这里，我们报告了第一个基于近红外到近红外信号的高效 LRET 系统，用于通过均相竞争性免疫测定检测孕激素，孕激素被选为概念验证靶标。为了提高 LRET 的效率，我们构建了惰性核/活性壳/惰性超薄壳 UCNPs（NaYF@NaYF：Yb，Tm@NaYF）作为 LRET 供体和紧凑的孕激素/辣根过氧化物酶/IRdyeQC-1（P-HRP-染料）复合物作为 LRET 受体。与传统的供体和受体（分别为 70%和 50%）相比，设计的供体和受体显示出明显提高的 LRET 效率（分别为 95%和 85%）。使用开发的近红外到近红外 LRET 系统，成功地以无背景信号和低检测限（在十倍稀释的人血清中为 1.36 pg/ml）检测到孕激素。我们相信，这里开发的高效基于近红外到近红外信号的 LRET 系统具有作为均相竞争性免疫测定的简单探针的潜力，具有快速检测生物标志物的能力。
