Molecules with ionizable protons, with different proton transfer efficiencies in the excited and ground states, show excited state prototropism (ESPT). In suitable proton donating/accepting environments, ESPT of a molecule can result in the observation of emissions from different prototropic species, each characterized by different emission spectra and different emission lifetimes. In condensed media, the immediate environment around the ESPT molecule can significantly influence the emission spectral parameters of different prototropic species. This forms the basis of ESPT based fluorescence sensing. The concept of ESPT has been widely used for probing dynamical and structural information of micro-heterogeneous media like micelles, polymers, lipid bilayer membranes, etc. ESPT molecules like naphthol and intra-molecular ESPT (ESIPT) molecules like hydroxyflavones etc., are said to be good multi-state fluorescent molecular probes if (i) the partitioning of these molecules to a micro-heterogeneous organized medium is more efficient, and (ii) the molecules possess distinct excitation and emission wavelengths corresponding to their different prototropic forms. The fluorescence of different prototropic forms shows a sensitive response towards the change in the local environment around the micro-heterogeneous organized medium concerning the physical properties, local structure, and dynamics. This review mainly comprises the work carried out on ESPT fluorescence molecular probing of biomimetic liposomes/lipid bilayer membranes from 1990 onwards.

中文翻译：

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基于激发态质子转移的荧光分子探针及其在研究脂质双层膜中的应用。

具有可电离质子的分子在激发态和基态下具有不同的质子传递效率，表现出激发态的原生质性（ESPT）。在合适的质子供体/接受环境中，分子的ESPT可以观察到来自不同质子体物种的发射，每种均以不同的发射光谱和不同的发射寿命为特征。在冷凝介质中，ESPT分子周围的周围环境会显着影响不同质子体物种的发射光谱参数。这构成了基于ESPT的荧光传感的基础。ESPT的概念已被广泛地用于探测动力学和微异质介质状胶束，聚合物，脂质双层膜，结构信息等。如果（i）将这些分子分配到微非均质的有组织的介质更有效，则可以说ESPT分子（如萘酚）和分子内ESPT（ESIPT）分子（如羟基黄酮等）是好的多态荧光分子探针。 （ii）分子具有对应于其不同质子形式的不同激发和发射波长。不同质子传递形式的荧光显示出对微观异质组织介质周围局部环境变化的敏感响应，涉及物理特性，局部结构和动力学。该综述主要包括从1990年开始对仿生脂质体/脂质双层膜进行ESPT荧光分子探测的工作。