High-stable Phosphorene-supported Bimetallic Pt-Pd Nanoelectrocatalyst for p-Aminophenol, β-Galactosidase, and Escherichia coli

Phosphorene (BP) is a rapidly rising star in two-dimensional (2D) layered nanomaterials beyond graphene, and its urgent issues of ambient instability still have to be resolved. Here, the bimetallic Pt-Pd nanoparticle on the BP surface was employed as multifunctional chemical and biochemical sensing platform for electrocatalytic detection of p -aminophenol (PAP), β-galactosidase (β-Gal), and Escherichia coli ( E. coli ). The BP-supported Pt-Pd nanoelectrocatalyst obtained by the electrodeposition of bimetallic Pt-Pd nanoparticle onto the BP surface was very stable in aqueous buffer containing oxygen, which displayed good voltammetric responses for PAP in a linear range of 0.02 -5 μmol·L -1 with a detection limit (LOD) of 1.41 × 10 −8 M and sensitivity 115.81 μA·μM -1 ·cm -2 . PAP could be obtained by the biochemical reaction of β-Gal in the presence of substrate PAP-β-galactopyranoside, which could realize for biochemical sensing of β-Gal in a linear range of 0.2 -0.8 mU·L -1 with a LOD of 9.35 nU·L -1 and sensitivity of 4.77 μA (mU·L -1 ) -1 ·cm -2 . The β-Gal is an indicator of total coliforms represented by E. coli that are induced by isopropyl-β-thiogalactopyranoside, which could applied for biochemical sensing of E. coli in a linear range of 6 × 106 –1.6 × 108 cfu·mL-1 with LOD of 6.65 × 10 5 cfu·mL -1 and sensitivity of 2.44 μA·(cfu·mL -1 ) -1 ·cm -2 . This work will provide experimental support for multifunctional chemical and biochemical sensing platform based on 2D layered nanomaterials decorated with bimetallic nanoelectrocatalysts.