An Xiangyang, Zhang Yuemei, Wang Jing, Kong De-Ming, He Xi-Wen, Chen Langxing, Zhang Yukui
College of Chemistry, Nankai University, Tianjin 300071, P. R. China.
Tianjin Key Laboratory of Biosensing and Molecular Recognition, Nankai University, Tianjin 300071, P. R. China.
ACS Omega. 2021 Jun 30;6(27):17501-17509. doi: 10.1021/acsomega.1c01983. eCollection 2021 Jul 13.
Cytochrome (Cyt ), one of the most significant proteins acting as an electron transporter, plays an important role during the transferring process of the energy in cells. Apoptosis, one of the major forms of cell death, has been associated with various physiological regularity and pathological mechanisms. It was found that Cyt can be released from mitochondria to cytosol under different pathological conditions, triggering subsequent cell apoptosis. Herein, we developed a fluorescence nanoprobe based on negatively charged CuInS-ZnS-GSH quantum dots (QDs) for the sensitive determination of Cyt . CuInS-ZnS-GSH QDs with high photochemical stability and favorable hydrophilicity were prepared by a simple hot reflux method and emit a bright orange-red light. The electron-deficient heme group in Cyt is affiliated with the electron-rich CuInS-ZnS-GSH QDs through the photo-induced electron transfer process, resulting in a large decrease in fluorescence intensity of QDs. A good linearity for concentration of Cyt in the range of 0.01-7 μmol L is obtained, and the detection limit of Cyt is as low as 1.1 nM. The performance on the detection of Cyt in spiked human serum and fetal bovine serum samples showed good recoveries from 85.5% to 95.0%. Furthermore, CuInS-ZnS-GSH QDs were applied for the intracellular imaging in HeLa cells showing an extremely lower toxicity and excellent biocompatibility.
细胞色素（Cyt）是最重要的电子传递蛋白之一，在细胞能量传递过程中发挥着重要作用。细胞凋亡是细胞死亡的主要形式之一，与多种生理规律和病理机制相关。研究发现，在不同病理条件下，Cyt可从线粒体释放到细胞质中，引发后续细胞凋亡。在此，我们开发了一种基于带负电荷的CuInS-ZnS-GSH量子点（QDs）的荧光纳米探针，用于灵敏测定Cyt。通过简单的热回流法制备了具有高光化学稳定性和良好亲水性的CuInS-ZnS-GSH QDs，其发射明亮的橙红色光。Cyt中缺电子的血红素基团通过光诱导电子转移过程与富电子的CuInS-ZnS-GSH QDs结合，导致QDs荧光强度大幅下降。在0.01-7 μmol L范围内，Cyt浓度具有良好的线性关系，Cyt的检测限低至1.1 nM。在加标人血清和胎牛血清样品中检测Cyt的性能显示，回收率在85.5%至95.0%之间。此外，CuInS-ZnS-GSH QDs应用于HeLa细胞的细胞内成像，显示出极低的毒性和优异的生物相容性。
