Gold nanoparticles-amplified laccase-based electrochemical biosensor using graphitized carbon@boron carbide as electron transfer promoter

[Display omitted] •In-situ electrodeposited AuNPs were used as signal amplifier.•GC@B4C particles were used as electron transfer promotor of laccase.•Lac/GC@B4C/AuNPs/NF electrode had good performance for catechol detection. A novel laccase-based electrochemical biosensor was developed based on graphitized carbon coated boron carbide (GC@B4C) particles and gold nanoparticles (AuNPs) as electron transfer promoter and signal amplifier, respectively. AuNPs were in-situ electrodeposited on nickel foam (NF) electrode, and chitosan was used to immobilize laccase (Lac) and GC@B4C particles on AuNPs/NF electrode. The fabricated Lac/GC@B4C/AuNPs/NF electrode showed excellent electrocatalytic activity and good electron transfer kinetics for catechol (CC) oxidation. In addition, Lac/GC@B4C/AuNPs/NF electrode exhibited wide linear range (0.1–500 µM), high sensitivity (157.3 µA mM−1), low detection limit (25 nM), desirable selectivity, favorable stability and satisfactory reproducibility for CC detection. This work provided new idea for the construction of laccase-based electrochemical biosensors.