Ramakrishna Mission Vidyamandira, Belur Math, Howrah 711202, India.
Center for Bio/Molecular Science and Engineering, Code 6900, U.S. Naval Research Laboratory, Washington, DC 20375, USA.
Sensors (Basel). 2020 May 21;20(10):2909. doi: 10.3390/s20102909.
Bioluminescence resonance energy transfer (BRET) is the non-radiative transfer of energy from a bioluminescent protein donor to a fluorophore acceptor. It shares all the formalism of Förster resonance energy transfer (FRET) but differs in one key aspect: that the excited donor here is produced by biochemical means and not by an external illumination. Often the choice of BRET source is the bioluminescent protein luciferase, which catalyzes the oxidation of a substrate, typically coelenterazine, producing an oxidized product in its electronic excited state that, in turn, couples with a proximal fluorophore resulting in a fluorescence emission from the acceptor. The acceptors pertinent to this discussion are semiconductor quantum dots (QDs), which offer some unrivalled photophysical properties. Amongst other advantages, the QD's large Stokes shift is particularly advantageous as it allows easy and accurate deconstruction of acceptor signal, which is difficult to attain using organic dyes or fluorescent proteins. QD-BRET systems are gaining popularity in non-invasive bioimaging and as probes for biosensing as they don't require external optical illumination, which dramatically improves the signal-to-noise ratio by avoiding background auto-fluorescence. Despite the additional advantages such systems offer, there are challenges lying ahead that need to be addressed before they are utilized for translational types of research.
生物发光共振能量转移（BRET）是生物发光蛋白供体向荧光团受体的非辐射能量转移。它具有Förster 共振能量转移（FRET）的所有形式，但在一个关键方面有所不同：这里的激发供体是通过生化手段产生的，而不是通过外部照明产生的。通常，BRET 源的选择是生物发光蛋白荧光素酶，它催化底物的氧化，通常是腔肠素，产生其电子激发态的氧化产物，进而与邻近的荧光团偶联，导致从受体发出荧光。与本讨论相关的受体是半导体量子点（QD），它具有一些无与伦比的光物理性质。除其他优点外，QD 的大斯托克斯位移特别有利，因为它允许轻松准确地解构受体信号，这在使用有机染料或荧光蛋白时很难实现。QD-BRET 系统在非侵入性生物成像和生物传感探针中越来越受欢迎，因为它们不需要外部光学照明，这通过避免背景自发荧光极大地提高了信噪比。尽管此类系统具有额外的优势，但仍存在一些挑战需要解决，然后才能将其用于转化研究。
