True FRET‐Based Sensing of pH via Separation of FRET and Photon Reabsorption
True FRET‐Based Sensing of pH via Separation of FRET and Photon Reabsorption
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DOI：
10.1002/adom.202200242
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发表时间：
2022-05
影响因子：
9
通讯作者：
Conrad Corbella Bagot;E. Rappeport;Ananda Das;Taleb Ba Tis;W. Park
中科院分区：
文献类型：
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作者：
Conrad Corbella Bagot;E. Rappeport;Ananda Das;Taleb Ba Tis;W. Park
基于Förster共振能量转移（FRET）的器件由于其高度局部化的响应性而被广泛研究为潜在的生物传感器。特别是，染料缀合的上转换纳米颗粒（UCNP）是最有前途的基于FRET的传感器候选者之一。UCNP具有允许比率传感的多模式发射曲线，并且通过将生物敏感染料缀合到其表面，该曲线可用于测量生物参数的局部变化。然而，UCNP能量分布的复杂性质以及发射光子的重吸收必须考虑在内，以便正确地感测目标参数。据作者所知，没有提出的基于UCNP的传感器可以准确地处理这些复杂问题。在这篇文章中，作者通过创建一种基于FRET的传感器来测量pH值，从而解释了这些复杂性。这种传感器利用了Thuronium（Tm3+）掺杂的UCNP和荧光染料异硫氰酸荧光素（FITC）。首先证明光子重吸收是475 nm Tm3+发射的严重问题，从而限制了其在基于FRET的传感中的使用。然后，它表明，通过采取的646和800 nm的发射，而不是更流行的475 nm的发射的比率，它是可以测量pH值专门通过FRET。
Förster resonance energy transfer (FRET)‐based devices have been extensively researched as potential biosensors due to their highly localized responsivity. In particular, dye‐conjugated upconverting nanoparticles (UCNPs) are among the most promising FRET‐based sensor candidates. UCNPs have a multi‐modal emission profile that allows for ratiometric sensing, and by conjugating a biosensitive dye to their surface, this profile can be used to measure localized variations in biological parameters. However, the complex nature of the UCNP energy profile as well as reabsorption of emitted photons must be taken into account in order to properly sense the target parameters. To the authors’ knowledge, no proposed UCNP‐based sensor has accurately taken care of these intricacies. In this article, the authors account for these complexities by creating a FRET‐based sensor that measures pH. This sensor utilizes Thulium (Tm3+)‐doped UCNPs and the fluorescent dye fluorescein isothiocyanate (FITC). It is first demonstrated that photon reabsorption is a serious issue for the 475 nm Tm3+ emission, thereby limiting its use in FRET‐based sensing. It is then shown that by taking the ratio of the 646 and 800 nm emissions rather than the more popular 475 nm one, it is possible to measure pH exclusively through FRET.