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

Graphical abstract A simple and sensitive electrochemical biosensor is constructed for the detection of telomerase activity based on the electrocatalysis of Pd/MIL101-NH 2 as a redox mediator. Highlights • A sensitive electrochemical biosensor is constructed for the detection of telomerase activity based on Pd/MIL101-NH 2. • This biosensor shows low limit of detection and wide dynamic correlation of telomerase activity. • The proposed method was enzyme-free and PCR-free without the requirement of any additional separation steps. Abstract 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-NH 2) 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-NH 2 towards oxidation of acetaminophen, this biosensor shows wide dynamic correlation of telomerase activity from 5 × 102 to 1.62 × 107 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. [ABSTRACT FROM AUTHOR]