Determination of Intracellular Esterase Activity Using Ratiometric Raman Sensing and Spectral Phasor Analysis.

Carboxylesterases (CEs) are a class of enzymes that catalyze the hydrolysis of esters in a variety of endogenous and exogenous molecules. CEs play an important role in drug metabolism, in the onset and progression of disease, and can be harnessed for prodrug activation strategies. As such, the regulation of CEs is an important clinical and pharmaceutical consideration. Here, we report the first ratiometric sensor for CE activity using Raman spectroscopy based on a bisarylbutadiyne scaffold. The sensor was shown to be highly sensitive and specific for CE detection and had low cellular cytotoxicity. In hepatocyte cells, the ratiometric detection of esterase activity was possible, and the result was validated by multimodal imaging with standard viability stains used for fluorescence microscopy within the same cell population. In addition, we show that the detection of localized ultraviolet damage in a mixed cell population was possible using stimulated Raman scattering microscopy coupled with spectral phasor analysis. This sensor demonstrates the practical advantages of low molecular weight sensors that are detected using ratiometric Raman imaging and will have applications in drug discovery and biomedical research.

羧酸酯酶（CEs）是一类能够催化多种内源性和外源性分子中酯水解的酶。CEs在药物代谢以及疾病的发生和发展中起着重要作用，并且可用于前药激活策略。因此，对CEs的调控是临床和药学上的一个重要考量。在此，我们报道了首个基于二芳基丁二炔支架的利用拉曼光谱检测CE活性的比率型传感器。该传感器对CE的检测显示出高度的敏感性和特异性，且细胞毒性较低。在肝细胞中，可以对比率型的酯酶活性进行检测，并且通过在同一细胞群中使用用于荧光显微镜的标准活性染色进行多模态成像验证了该结果。此外，我们表明，利用受激拉曼散射显微镜结合光谱相量分析，可以检测混合细胞群中的局部紫外线损伤。这种传感器展示了使用比率型拉曼成像检测的低分子量传感器的实际优势，并将在药物研发和生物医学研究中得到应用。