A sensitive and selective pyrosine sensor based on palygorskite-graphene modified electrode

Palygorskite-graphene composite was obtained by the electrochemical reduction of palygorskite-graphene oxide (GO), and the resulted palygorskite-graphene modified glassy carbon electrode (GCE) was used as the amperometric sensor for pyrosine determination. Compared to the graphene modified GCE, the detecting sensitivity of pyrosine was greatly improved at the palygorskite-graphene modified GCE. This was mainly attributed to the high adsorption capability of palygorskite. The effect of the mass ratio of GO to palygorskite was investigated, and the optimum mass ratio of GO to palygorskite was chosen as 2:1. The calibration curve was linear for pyrosine concentration from 21 to 598 μM, and the detection limit was as low as 5.98 nM (signal-to-noise ratio of 3). The palygorskite-graphene modified GCE also had satisfactory fabrication reproducibility, good determination precision and high detecting selectivity for pyrosine.