Fabrication of amine-functionalized metal-organic frameworks with embedded palladium nanoparticles for highly sensitive electrochemical detection of telomerase activity

As a critical biomarker for early cancer diagnostics, telomerase activity has attracted extensive attention concerning its monitoring and detection. Herein, a simple and sensitive electrochemical biosensor is constructed for the detection of telomerase activity based on the electrocatalysis of Pd nanoparticles anchored on amine functionalized Cr-based metal-organic frameworks (Pd/MIL101-NH2) as a redox mediator. 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 Pd/MIL101-NH2 towards oxidation of acetaminophen, this biosensor shows wide dynamic correlation of telomerase activity from 5 x 10(2) to 1.62 x 10(7) HeLa cells mL(-1) and the limit of detection was calculated to be 11.25 HeLa cells mL(-1), providing a powerful platform for detecting telomerase activity.