Concave PdCu nanocubes coated with Pt Island shells for neutral glucose electrocatalysis and detection

In this study, a seed-growth method is developed to synthesise concave and core-shell PdCu/Pt nanocubes using concave PdCu nanocubes as seeds. The resulting structures include PdCu_0.2@Pt CNCI, PdCu_0.5@Pt CNCI, and PdCu@Pt CNCI (concave PdCu nanocubes coated with Pt islands), as well as PdCu_1.5@Pt SNC (stellated and core-shell nanocubes). These structures catalyse neutral d-glucose oxidation reactions (GORs). The Pt island deposition follows the trend: PdCu_1.5@Pt SNC < PdCu@Pt CNCI < PdCu_0.5@Pt CNCI < PdCu_0.2@Pt CNCI, controlled by the fractional addition of Cu during synthesis. Among these, PdCu@Pt CNCI samples demonstrate the highest mass activity (M_A) of 1.0 × 10²⁶ molecules·g^-1_Pt for sequential GOR catalysis, surpassing other PdCu/Pt catalysts. Notably, this activity is 30.3 times greater than that of Pt nanoparticles (3.3 × 10²⁴ molecules·g^-1_Pt). For transient GOR catalysis, PdCu_1.5@Pt SNC, with reduced Pt content, displays remarkable non-enzymatic glucose sensing sensitivities of 42.14 μA·mM^-1·cm^-2 and 23.43 μA·mM^-1·cm^-2 over linear ranges of 0.25-2 mM and 2-10 mM, respectively. Its high recovery rates (≥ 97.92 %) and low relative standard deviations (≤ 1.89 %) in serum and energy drink samples highlight its potential as a non-enzymatic glucose sensor.