荧光水凝胶传感器及其传感响应机制研究进展

Fluorescent Polymeric Hydrogels Sensors and Their Sensing Mechanisms: a Review

荧光水凝胶是一类具有三维交联网络、荧光发射性能的新型高分子复合材料,能够在外界目标分析物的刺激下发生荧光强度或荧光发射颜色的改变。因此,荧光水凝胶能够作为定量检测目标分析物浓度的重要工具,并且表现出良好的荧光稳定性与检测便携性。近年来,研究人员开发出了多种基于不同类型响应机制的荧光水凝胶传感探针,并应用于各种类型目标分析物的检测。在传统的荧光水凝胶传感器的设计过程中,大多数是基于目标分析物与水凝胶内部的荧光材料间高度的特异性识别功能,这需要目标分析物与荧光材料之间的高度一一对应关系,限制了此类荧光水凝胶传感器的检测广泛性。然而,通过间接性作用构建的荧光水凝胶能够引入一个中间媒介作为桥梁进一步实现各类目标分析物的特异性识别与响应。该种级联响应目标分析物的方式打破了传统荧光水凝胶传感器的局限性。本文根据荧光水凝胶传感体系构建过程中所涉及到的信号响应机制,将荧光水凝胶传感器分为三大类,主要包括直接响应型、竞争性响应型、非竞争性响应型,这对于启发人们构建新型荧光水凝胶传感器具有重要的参考意义。最后,对荧光水凝胶传感器在检测领域所面临的机遇与挑战进行了总结与展望。

Fluorescent hydrogel is a new type of polymer composite with three-dimensional cross-linked networks and fluorescence emission properties. The fluorescence intensity or fluorescence emission color can change under the stimulation of external target analytes. Hence, fluorescent hydrogel can serve as an essential tool for the quantitative detection of target analyte concentration, while also offering good fluorescence stability and detection portability. In recent years, researchers have developed various fluorescent hydrogel sensing probes based on different types of response mechanisms, and have applied them in the detection of various types of target analytes. The design of traditional fluorescent hydrogel sensors is typically based on a highly specific recognition function between the target analytes and fluorescent material inside the hydrogel, which requires a high one-to-one correspondence between the target analytes and fluorescent material, limiting the detection range of such fluorescent hydrogel sensors. However, fluorescent hydrogels based on indirect interaction can introduce an intermediate medium as a bridge to further achieve specific recognition and response to various target analytes. This cascade response to target analytes overcomes the limitations of conventional fluorescent hydrogel sensors. Based on the signal response mechanisms involved in the fabrication of fluorescent hydrogel sensing systems, the fluorescent hydrogel sensors are classified into three major categories in this paper: direct response, competitive response, and non-competitive response. This paper provides important insights for the fabrication of new fluorescent hydrogel sensors. Finally, the prospects and challenges associated with fluorescent hydrogel sensors in the field of detection are summarized and discussed.