单颗粒荧光闪烁现象、机理与应用

Phenomenon,Mechanism and Applications of Single Particle Fluorescence Blinking

荧光闪烁现象是指单个荧光生色团在稳定的激发光照射下,其荧光发射具有出乎意料的间歇性,即荧光强度在"亮态"和"暗态"之间随机、显著、频繁转换。这一现象首先在有机荧光分子、荧光蛋白和半导体量子点中被发现,随后的研究表明其在多种类型的荧光纳米材料中具有一定的普遍性。荧光闪烁现象极大地促进了人们对分子与半导体光物理过程的认识和理解,为荧光材料在生物传感与成像、光电器件等领域的深入应用带来了机遇和挑战。该文简要描述了荧光闪烁现象的主要特征和研究现状,系统介绍了其光物理机制。通过对几类典型材料荧光闪烁特性的综述,着重讨论了其在多个应用领域中的利与弊,并对今后的发展方向进行了展望。

Fluorescence blinking means that,even under the constant illumination,the fluorescence emission of a single fluorophore exhibits surprising intermittency,i.e.the random,significant and frequent switching between“bright”and“dark”states.This phenomenon was first discovered in organic fluorescent molecules,fluorescent proteins and semiconductor quantum dots.Subsequent studies showed that it was often observed in versatile types of fluorescent nanomaterials.Fluorescence blinking has not only deepened greatly the fundamental understanding on the photophysical processes of molecules and semiconductors,but also brought opportunities and challenges for the in-depth applications of fluorescent materials in broad fields such as biosensing,imaging and optoelectronic devices.In this review,the main characteristics and research status of fluorescence blinking are briefly described,and the photophysical mechanism behind it is also systematically introduced.By reviewing the fluorescence blinking characteristics of several kinds of typical nanomaterials,the advantages and disadvantages of fluorescence blinking are discussed.Finally,the future trend in this field is prospected.