Highly sensitive amperometric detection of bilirubin using enzyme and gold nanoparticles on sol-gel film modified electrode

► The enzyme incorporated AuNPs on sol-gel film electrode is highly sensitive toward the electro-oxidation of bilirubin. ► The electrocatalytic oxidation current of bilirubin increased linearly from 1 to 5000 μM at enzyme-modified electrode with a correlation coefficient of 0.9960. ► Using an amperometric method, the detection limit of bilirubin was found to be 1.4 nM (S/N = 3). ► The practical application of the modified electrode was demonstrated by measuring the concentration of bilirubin in blood serum.