Abstract:

In recent years, significant advances have been made in the field of genetically encoded fluorescent sensors. Fluorescent protein-based sensors have seen continuous improvements in performance, with researchers employing protein engineering techniques to develop brighter and more photostable fluorescent protein variants, as well as extending their emission spectra into the far-red region for deeper tissue imaging. Concurrently, innovative sensing mechanisms have emerged, such as the incorporation of genetically encoded unnatural fluorescent amino acids to construct miniaturized fluorescent reporter molecules, and strategies utilizing protein conformational changes or Förster resonance energy transfer (FRET) to sensitively detect biological signals. Researchers have also developed highly specific fluorescent sensors targeting particular biomarkers, including genetically encoded sensors for detecting ions, metabolites, or enzyme activities, providing powerful tools for precise monitoring of cellular physiological processes. Meanwhile, RNA fluorescent aptamers, another major category of genetically encoded sensors, have achieved substantial progress in structural optimization and functional expansion. Newly screened and engineered fluorescent aptamers exhibit enhanced affinity and specificity toward their fluorescent ligands, significantly improving fluorescence activation efficiency. Certain aptamer-ligand complexes now exhibit brightness comparable to, or even exceeding, traditional fluorescent proteins. Various combinations of aptamers and fluorophores currently cover emission spectra ranging from visible to near-infrared. These RNA-based sensors have successfully enabled the labeling and visualization of endogenous RNA molecules in living cells, facilitating real-time tracking of RNA localization and dynamics. Furthermore, combining fluorescent aptamers with small-molecule recognition aptamers has enabled the creation of novel fluorescent "switch" sensors, whose fluorescence is activated through conformational changes triggered by the presence of specific metabolites. Both types of genetically encoded sensors demonstrate substantial value in disease diagnosis. For instance, fluorescent protein-based biosensors can monitor abnormal fluctuations of intracellular metabolites and signaling molecules, such as glucose or ATP levels, aiding in the elucidation of metabolic characteristics in diseases like diabetes and cancer. Utilizing improved near-infrared fluorescent proteins and fluorescent aptamers in vivo allows deeper tissue penetration and facilitates early detection of pathological changes, such as tumors. Additionally, fluorescent sensors specifically designed for pathological states-such as oxidative stress, pH imbalance, or particular enzyme activities—can directly report disease signals at the cellular level, supporting precise diagnostics. Overall, these advancements significantly enhance the sensitivity and specificity of biological imaging and molecular diagnostics. Looking forward, as sensor performance continues to improve and new sensing principles emerge, genetically encoded fluorescent sensors will play increasingly prominent roles in more complex biological systems and clinical diagnostics, exhibiting tremendous potential for future applications.

Key words: genetically encoded fluorescent sensors, fluorescent proteins, fluorescent aptamers, molecular imaging, disease diagnosis

摘要：

近年来，遗传编码荧光探针在结构优化与疾病诊断应用中取得了快速发展。通过蛋白质工程，荧光蛋白在光稳定性、灵敏度和光谱范围方面显著提升，并涌现出多种新型传感机制，实现了离子、代谢物及神经递质等生理信号的实时可视化。与此同时，荧光RNA在折叠稳定性、激活效率和亮度上不断突破，多色工具箱的建立使 RNA 动态成像成为可能。这两类探针已广泛应用于肿瘤代谢、糖尿病及神经疾病研究，在代谢监测、病理状态识别和早期诊断等方面展现出独特优势，推动了疾病机制解析与诊断技术进步。未来，随着探针性能持续优化和设计创新，遗传编码荧光探针有望在基础研究和临床转化中发挥更大作用，为精准诊断和个性化医疗提供有力支持。

关键词: 遗传编码荧光探针, 荧光蛋白, 荧光RNA, 分子成像, 疾病诊断