Yu Ji, Yang Anneng, Wang Naixiang, Ling Haifeng, Song Jiajun, Chen Xi, Lian Yadong, Zhang Zhishan, Yan Feng, Gu Min
National Laboratory of Solid State Microstructures and Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, P.R. China.
Nanoscale. 2021 Feb 7;13(5):2868-2874. doi: 10.1039/d0nr08453k. Epub 2021 Jan 19.
Caspase-3 is an important proteolytic enzyme that cleaves several key substrates in apoptotic processes, resulting in DNA fragmentation, the degradation of nuclear proteins, and the formation of apoptotic bodies. However, it is challenging to detect caspase-3 due to its low expression levels in cells. In this work, organic electrochemical transistors (OECTs) are used in the detection of caspase-3 for the first time. A self-assembled monolayer of the peptide is bonded to the Au gate electrode (GE) of an OECT via gold-sulphur bonds. It is found that the transfer curve of the transistor shifts to a lower gate voltage due to the modulation of the surface potential of the GE by the peptides. Then, the device is used in the detection of caspase-3 in aqueous solutions and shows a detection limit of 0.1 pM. Due to its high sensitivity, the device can detect caspase-3 in induced apoptotic HeLa cells. The system is low-cost, conveniently used and applicable for biological and medical monitoring where caspase-3 detection and quantification are required.
半胱天冬酶-3是一种重要的蛋白水解酶，可在凋亡过程中切割多种关键底物，导致DNA片段化、核蛋白降解以及凋亡小体的形成。然而，由于其在细胞中的低表达水平，检测半胱天冬酶-3具有挑战性。在这项工作中，首次将有机电化学晶体管（OECT）用于半胱天冬酶-3的检测。肽的自组装单层通过金硫键与OECT的金栅电极（GE）结合。发现由于肽对GE表面电位的调制，晶体管的转移曲线向较低的栅极电压移动。然后，该装置用于检测水溶液中的半胱天冬酶-3，检测限为0.1 pM。由于其高灵敏度，该装置可以检测诱导凋亡的HeLa细胞中的半胱天冬酶-3。该系统成本低、使用方便，适用于需要检测和定量半胱天冬酶-3的生物和医学监测。
