Facile Synthesis of β-Lactoglobulin-Functionalized Reduced Graphene Oxide and Trimetallic PtAuPd Nanocomposite for Electrochemical Sensing

Abstract

The use of graphene has leapt forward the materials field and the functional modification of graphene has not stopped. In this work, β-lactoglobulin (BLG) was used to functionalize reduced graphene oxide (RGO) based on its amphiphilic properties. Also, trimetallic PtAuPd nanoparticles were reduced to the surface of BLG-functionalized RGO and formed BLG-PtAuPd-RGO nanocomposite using facile synthesis. Transmission electron microscopy, energy-dispersive X-ray spectroscopy and Fourier transform infrared spectra were used to characterize the nanocomposite. Electrocatalytic analysis was evaluated through cyclic voltammetry and chronoamperometry methods. We developed a glucose sensor by fabricating GOD-BLG-PtAuPd-RGO/glassy carbon (GC) electrode. It presented a remarkable sensitivity of 63.29 μA mM−1 cm−2 (4.43 μA mM−1), a wider linear range from 0.005 to 9 mM and a lower detection limit of 0.13 μM (S/N = 3). Additionally, the glucose sensor exhibited excellent testing capability in human serum samples.

Keywords

• graphene
• β-lactoglobulin
• PtAuPd alloy
• electrochemical sensing
• glucose sensor