Electrochemistry of cholesterol biosensor based on a novel Pt-Pd bimetallic nanoparticle decorated graphene catalyst

► A new biosensor with enhanced sensitivity was developed for detection of cholesterol. ► Using Pt-Pd-CS-GS hybrid nanocomposites functionalized glassy carbon electrode. ► Accelerated direct electron transfer from the redox enzyme to the electrode surface. ► Reveal the specific cholesterol catalytic activity of the biosensor.