Highly sensitive detection of telomerase based on poly-adenine primer and DNA-templated copper nanoparticles

Telomerase is a potential diagnostic biomarker for a variety of cancers. Development of sensitive and convenient methods to measure the activity of telomerase is of great importance. Herein, an electrochemical method is fabricated with self-assembled poly-adenine (polyA) based primer. Target telomerase catalyzes the extension of primer and the product with multiple repeated sequences captures abundant DNA-templated copper nano-particles (CuNPs). The nanomaterials act as electrochemical signal sources. CuNPs can be further dissolved and detected with significant voltammetric responses. This developed electrochemical biosensor exhibits a wide dynamic range from 10 to 5 x 104 cell/mL and low limit of detection (2 cells/mL). The satisfactory performances are due to the excellent electrochemical properties of CuNPs and target induced enrichment effect. This method provides an effective approach for the telomerase activity monitoring in cancer diagnostics.