The Higher Educational Key Laboratory for Nano Biomedical Technology of Fujian Province, School of Pharmacy, Fujian Medical University, Fuzhou, 350122, China.
College of Ecological Environment and Urban Construction, Fujian University of Technology, Fuzhou, 350108, China.
Biosens Bioelectron. 2022 May 15;204:114070. doi: 10.1016/j.bios.2022.114070. Epub 2022 Feb 5.
In this work, we report on a portable photoelectrochemical (PEC) sensing system for telomerase activity detection based on dual biomineralized ZIF-8 nanoparticles (NPs)-medicated conversion of chemical energy to electricity and terminal deoxynucleoside transferase (TdTase)-catalyzed elongation of Y-junction DNA structure. Two kinds of biomineralized ZIF-8 NPs including glucose oxidase (GOx)-encapsulated ZIF-8 (GZIF) and horseradish peroxidase (HRP)-encapsulated ZIF-8 (HZIF) are involved in this assay system. The recognition of telomerase is started with telomerase-catalyzed elongation of a telomerase substrate (TS) primer, which generates a longer elongation chain to trigger the formation of a Y-junction DNA structure. The Y-junction DNA with abundant 3'-OH terminal and small steric hindrance facilitates the implement of TdTase-catalyzed elongation reaction, in which the branches of Y-junction DNA are elongated and endowed with biotin moiety to capture streptavidin-modified GZIF (SA-GZIF). The signal transduction is then achieved on a luminol/HZIF/CdS-based photoelectrode. Once the HO produced from GZIF-catalyzed hydrolysis of glucose is introduced to the photoelectrode, chemiluminescence of HRP-luminol-HO-p-iodo-phenol (PIP) system confined in HZIF is activated to excite photocurrent of CdS NPs, which is then recorded by a portable digital multimeter (DMM). The developed PEC sensing system possesses a wide calibration range from 50 to 5000 HeLa cells and a low detection limit of 46 cells. Significantly, the sensing platform is successfully applied to evaluate the telomerase activity in resected bladder tumor tissues. This work not only provides a diagnostic tool for telomerase-related diseases but also open a new avenue for establishing PEC assay methods using metal-organic framework (MOF) NPs.
在这项工作中，我们报告了一种基于双生物矿化 ZIF-8 纳米粒子（NPs）将化学能转化为电能和末端脱氧核苷酸转移酶（TdTase）催化 Y 型 DNA 结构延伸的光电化学（PEC）传感系统，用于端粒酶活性检测。该测定系统涉及两种生物矿化 ZIF-8 NPs，包括葡萄糖氧化酶（GOx）包裹的 ZIF-8（GZIF）和辣根过氧化物酶（HRP）包裹的 ZIF-8（HZIF）。端粒酶的识别始于端粒酶催化端粒酶底物（TS）引物的延伸，该延伸生成更长的延伸链以触发 Y 型 DNA 结构的形成。具有丰富 3'-OH 末端和较小空间位阻的 Y 型 DNA 有利于 TdTase 催化的延伸反应的实施，其中 Y 型 DNA 的分支被延伸并赋予生物素部分以捕获链霉亲和素修饰的 GZIF（SA-GZIF）。然后，信号转导在基于鲁米诺/HZIF/CdS 的光电电极上实现。一旦从 GZIF 催化的葡萄糖水解中引入产生的 HO 到光电电极，HRP-鲁米诺-HO-对碘苯酚（PIP）系统在 HZIF 中的化学发光被激活以激发 CdS NPs 的光电流，然后由便携式数字多用表（DMM）记录。所开发的 PEC 传感系统具有从 50 到 5000 个 HeLa 细胞的宽校准范围和 46 个细胞的低检测限。值得注意的是，该传感平台成功应用于评估切除的膀胱肿瘤组织中的端粒酶活性。这项工作不仅为与端粒酶相关的疾病提供了一种诊断工具，而且为建立使用金属有机框架（MOF）NPs 的 PEC 分析方法开辟了新途径。
