A label-free electrochemical biosensor for ultra-sensitively detecting telomerase activity based on the enhanced catalytic currents of acetaminophen catalyzed by Au nanorods.

Affiliation

Key Laboratory of Analytical Science and Technology of Hebei Province, College of Chemistry and Environmental Science, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, Ministry of Education, Hebei University, 071002 Baoding, PR China. Electronic address: [Email]

Abstract

An electrochemical biosensor was designed for the determination of telomerase activity using an enzyme-free, PCR-free, and convenient electrochemical strategy. In this work, the electrochemical biosensor was constructed through the functionalization of Au nanorods with a carboxylic group (AuNRs-3) and subsequent immobilization with capture DNA (cDNA) for sensing telomerase activity. Upon telomerase triggered extension, the telomerase activity is related to the amount of the adsorbed electrocatalyst, leading to the different electrochemical signals for readout. Integrating with the efficient electrocatalysis of AuNRs-3-cDNA towards oxidation of acetaminophen, the prepared biosensor exhibits a wide dynamic correlation of telomerase activity from 1 × 102 to 1.04 × 107 HeLa cells mL-1 with a sensitivity of 2.68 HeLa cell mL-1 and the limit of detection was calculated to be 52.81 HeLa cells mL-1 under the optimal experimental conditions. Furthermore, the application of this electrochemical biosensor would provide the great potential for analysis of telomerase activity, revealing a powerful platform for early diagnosis of cancers.

Keywords

Au nanorods,Electrochemical biosensor,Telomerase activity,Ultra-sensitivity detecting,