Herein we report on a novel magneto-controlled photoelectrochemical (PEC) sensor for sensitive detection of telomerase activity based on an electron-acceptor elimination strategy. For telomerase activity sensing, a telomerase substrate (TS) primer is anchored on the surface of magnetic beads (MBs). Under telomerase catalysis, the TS primer is extended to generate longer G-rich single strand DNA, which can bind with hemin to form G-quadruplex/hemin complexes. Based on this mechanism, the resulting MBs are used to capture hemin molecules in electrolyte solution and reduce their concentration. Since hemin acts as electron acceptor for a p-CuBi₂O₄ nanorod-based photocathode, a decrease in hemin concentration will lead to a decreasing photocurrent signal. By recording the decay of the photocurrent, the telomerase activity can be monitored with high sensitivity. Under optimal conditions, the developed sensor allows measurement of telomerase activity in cell extracts over the range 100–2000 HeLa cells with the limit of detection (LOD) as low as 53 cells (S/N = 3). The practicability of the developed method is also demonstrated by using it to screen telomerase inhibitors.

在这里，我们报告了一种新型的磁控光电化学（PEC）传感器，可基于电子受体消除策略灵敏地检测端粒酶活性。为了检测端粒酶活性，将端粒酶底物（TS）引物锚固在磁珠（MBs）的表面上。在端粒酶催化下，TS引物被延伸以产生更长的富含G的单链DNA，其可以与血红素结合形成G-四链体/血红素复合物。基于此机制，所得的MB用于捕获电解质溶液中的血红素分子并降低其浓度。由于血红素充当p -CuBi ₂ O _4的电子受体基于纳米棒的光阴极，血红素浓度的降低将导致光电流信号的降低。通过记录光电流的衰减，可以以高灵敏度监测端粒酶活性。在最佳条件下，开发的传感器可以测量100–2000 HeLa细胞范围内的细胞提取物中的端粒酶活性，检测限（LOD）低至53个细胞（S / N = 3）。通过使用该方法筛选端粒酶抑制剂，也证明了该方法的实用性。