Galvanic Replacement Synthesis of VOx@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) (VOx@EGaIn-PEG). By leveraging the excellent charge transfer properties and the low band gap of the LM surface oxide, the VOx@EGaIn-PEG heterojunction can effectively convert hydrogen peroxide into hydroxyl radicals, demonstrating excellent peroxidase-like activity and stability (Km = 490 μM, vmax = 1.206 μM/s). The unique self-healing characteristics of LM further enable the recovery and regeneration of VOx@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.