The point of care testing (POCT) of telomerase activity is critical for early diagnosis of cancer. Herein, a colorimetric method was developed for visual detection of telomerase activity via hydrogen peroxide test strip. It is based on the telomerase-controlled in-situ formation of hydrogen peroxide. Firstly, biotinylated telomerase substrate (TS) primer was attached on the surface of magnetic beads (MBs) via the streptavidin-biotin reaction to form MB-TS complex. Then, TS primers were elongated by telomerase to form long telomere elongated products (TEP) which contains TTAGGG repeat units. The in-situ formed MB-TEP complex specifically hybridized with glucose oxidase modified cDNA (GOD-cDNA). After magnetic separation and washing, the MB-TEP/GOD-cDNA complex incubated with glucose solution to in-situ produce hydrogen peroxide which was detected by hydrogen peroxide test strip. One long TEP hybridized with multiple GOD-cDNAs, which enriched GOD to highly efficiently catalyze glucose for generating hydrogen peroxide. Thus, the visual assay achieved sensitive detection of telomerase activity, and the limit of detection (LOD) reached as low as 10 HeLa cells/μL by naked eyes and 4.5 HeLa cells/μL by absorbance measurements. Therefore, it offers a sensitive and low-cost method for visual detection of telomerase activity, which also, widens the application of commercial hydrogen peroxide test strip in the development of non-H₂O₂ biosensors.

端粒酶活性的即时检测（POCT）对于癌症的早期诊断至关重要。在此，开发了一种比色法，用于通过过氧化氢试纸条目测端粒酶活性。它基于端粒酶控制的过氧化氢原位形成。首先，通过链霉亲和素-生物素反应将生物素化的端粒酶底物（TS）引物附着在磁珠（MBs）的表面上，形成MB-TS复合物。然后，TS引物被端粒酶拉长形成包含TTAGGG重复单元的长端粒拉长产物（TEP）。原位形成的MB-TEP复合物与葡萄糖氧化酶修饰的cDNA（GOD-cDNA）特异性杂交。经过磁分离和洗涤后，MB-TEP / GOD-cDNA复合物与葡萄糖溶液一起孵育以原位产生过氧化氢，用过氧化氢试纸检测。一个长的TEP与多个GOD-cDNA杂交，后者富集了GOD以高效催化葡萄糖生成过氧化氢。因此，目测法实现了端粒酶活性的灵敏检测，肉眼观察到的检出限（LOD）低至10 HeLa细胞/μL，吸光度测量检出限（LOD）达到4.5 HeLa细胞/μL。因此，它为目视检测端粒酶活性提供了一种灵敏且低成本的方法，这也扩大了商业化过氧化氢试纸在非H研发中的应用。富含GOD，可高效催化葡萄糖生成过氧化氢。因此，目测法实现了端粒酶活性的灵敏检测，肉眼观察到的检出限（LOD）低至10 HeLa细胞/μL，吸光度测量检测限达到了4.5 HeLa细胞/μL。因此，它为目视检测端粒酶活性提供了一种灵敏且低成本的方法，这也扩大了商业化过氧化氢试纸在非H研发中的应用。富含GOD，可高效催化葡萄糖生成过氧化氢。因此，目测法实现了端粒酶活性的灵敏检测，肉眼观察到的检出限（LOD）低至10 HeLa细胞/μL，吸光度测量检测限达到了4.5 HeLa细胞/μL。因此，它为目视检测端粒酶活性提供了一种灵敏且低成本的方法，这也扩大了商业化过氧化氢试纸在非H研发中的应用。₂ O ₂生物传感器。