Bimetallic PdCu nanoparticle decorated three-dimensional graphene hydrogel for non-enzymatic amperometric glucose sensor

A bimetallic PdCu nanoparticle (NP) decorated three-dimensional graphene hydrogel (PdCu/GE) was developed by a simple one-step hydrothermal method. The PdCu/GE hybrids exhibited an interconnected microporous framework with PdCu NPs dispersed and encapsulated within the GE layers. The PdCu/GE hybrids showed significant electrocatalytic activity toward glucose oxidation due to the synergistic effect of PdCu NPs and GE sheets in the alkaline solution containing chloride ions, presenting a substantial increase in the oxidation current and decrease in the onset potential of oxidation compared to the monometallic modified GE hybrids. At an applied potential of −0.4 V, the PdCu/GE modified electrode with optimized bimetallic ratio presented quick respond to glucose oxidation with a wide linear range up to 18 mM and a reproducible sensitivity of 48 μA (mg mM)−1 in the presence of chloride ions. Furthermore, the PdCu/GE modified electrode exhibited high selectivity to glucose and resistance against poisoning by commonly interfering species such as dopamine, ascorbic acid, uric acid, acetamidophenol and some monosaccharides. The PdCu/GE hybrid hydrogels with 3D micropores were therefore promising for the future development of non-enzymatic amperometric glucose sensors with improved electrochemical performances.