Yang Ying, Ma Yuanqing, Gooding J Justin
School of Chemistry and Australian Centre for NanoMedicine, University of New South Wales, Sydney 2052, Australia.
Faraday Discuss. 2025 Feb 17;257(0):333-343. doi: 10.1039/d4fd00111g.
Recently it has been shown that electrochemistry, instead of using high intensity lasers, can be used to modulate the intensity of emission of fluorophores and even switch fluorophores between their ON and OFF states as required for single molecule localisation microscopy. This modulation of fluorescence does not necessarily correlate with direct oxidation and reduction of the dyes. Questions arise from this unexpected observation related to what is the electrochemistry that occurs, what are the important variables in switching fluorophores electrochemically and what range of dyes can be modulated with electrochemistry. Herein we seek to answer some of these questions. We demonstrate how to effectively modulate the fluorescence intensity of organic dye-labelled cell samples on an indium tin oxide surface using electrochemistry with redox-active mediators present in an oxygen scavenger buffer. We showed the electrochemical fluorescence modulation is sensitive to the applied potential and the excitation laser intensity, indicating the possibility of coupled photochemical and electrochemical reactions occurring. We also compared the electrochemical fluorescence modulation of representative oxazine, rhodamine, and cyanine dyes using ATTO 655, Alexa Fluor 488, and Alexa Fluor 647. Different dyes with distinctly different structural cores show fluorescence modulation to different extents. The electrochemical fluorescence modulation will be applicable in fluorescence imaging techniques as well as biosensing.
最近研究表明，电化学方法可用于调节荧光团的发射强度，甚至能根据单分子定位显微镜的需要，将荧光团在其开启和关闭状态之间切换，而无需使用高强度激光。这种荧光调制不一定与染料的直接氧化和还原相关。这一意外发现引发了一些问题，比如发生的是什么电化学过程，电化学切换荧光团时的重要变量有哪些，以及哪些范围的染料可以用电化学方法进行调制。在此，我们试图回答其中一些问题。我们展示了如何在含有氧化还原活性介质的氧清除缓冲液中，通过电化学方法有效地调节氧化铟锡表面上有机染料标记的细胞样本的荧光强度。我们发现电化学荧光调制对施加的电位和激发激光强度敏感，这表明可能发生了光化学反应和电化学反应的耦合。我们还使用ATTO 655、Alexa Fluor 488和Alexa Fluor 647比较了代表性的恶嗪、罗丹明和花菁染料的电化学荧光调制。具有明显不同结构核心的不同染料显示出不同程度的荧光调制。电化学荧光调制将适用于荧光成像技术以及生物传感。
