Galvanic Replacement Synthesis of VO_x@EGaIn–PEG Core–Shell Nanohybrids for Peroxidase Mimics

The development of high-performance biosensors is a key focus in the nanozyme field, but the current limitations in biocompatibility and recyclability hinder their broader applications. Herein, we address these challenges by constructing core–shell nanohybrids with biocompatible poly(ethylene glycol) (PEG) modification using a galvanic replacement reaction between orthovanadate ions and liquid metal (LM) (VO x @EGaIn-PEG). By leveraging the excellent charge transfer properties and the low band gap of the LM surface oxide, the VO x @EGaIn-PEG heterojunction can effectively convert hydrogen peroxide into hydroxyl radicals, demonstrating excellent peroxidase-like activity and stability ( K m = 490 μM, v max = 1.206 μM/s). The unique self-healing characteristics of LM further enable the recovery and regeneration of VO x @EGaIn-PEG nanozymes, thereby significantly reducing the cost of biological detection. Building upon this, we developed a nanozyme colorimetric sensor suitable for biological systems and integrated it with a smartphone to create an efficient quantitative detection platform. This platform allows for the convenient and sensitive detection of glucose in serum samples, exhibiting a good linear relationship in the range of 10–500 μM and a detection limit of 2.35 μM. The remarkable catalytic potential of LM, combined with its biocompatibility and regenerative properties, offers valuable insights for applications in catalysis and biomedical fields.