The rational design of colloidal interfaces with spatiotemporal control over electromagnetic coupling is essential for enhancing the sensitivity of surface-enhanced Raman scattering (SERS) sensitivity. In this study, we propose a tyramine-triggered Ag Au nanoassembly strategy, driven by enzymatic polymerization-mediated interfacial engineering. The horseradish peroxidase/H₂O₂ system induces oxidative crosslinking of tyramine-functionalized Ag nanoparticles (Ag NPs), facilitating precise assembly with antigen-immobilized Au substrates to generate plasmonic architectures. Finite-difference time-domain simulations show that the Au Ag bilayer configuration exhibits enhanced electromagnetic field intensity compared to monolayer Au NPs or Ag NPs. This enhancement is attributed to synergistic interfacial coupling at the Au Ag nanogaps and intra-layer plasmon resonance. The dynamic nanoassembly achieved ultrasensitive aflatoxin B₁ detection with a limit of detection of 0.11 pg/mL, high interference resistance, and a wide dynamic range (0.001–100 ng/mL). The quantitative detection of AFB₁ in real samples demonstrates excellent accuracy (95.7–109.7 %) and precision (RSD < 7.5 %). By integrating enzymatic colloidal control with interfacial electromagnetic engineering, this work establishes a new paradigm for field-deployable mycotoxin monitoring in complex food systems.
Polyetheretherketone (PEEK) is increasingly recognized as a promising biomaterial for orthopedic implants due to its mechanical properties that are very similar to those of human bones. However, its inherent bioinertness still poses a challenge to effective osseointegration, and surface modification of PEEK implants often faces limitations such as multi-step complexity. In this study, we innovatively developed a dopamine-triggered one-step polymerization of 3-[(3-acrylamidopropyl)dimethylammonio] propanoate (PCBAA), which in situ induced biomineralization and constructed a functional PEEK biointerfaces, directly and effectively enhancing osseointegration and antibacterial effects. The successful immobilization of PCBAA on the surface of PEEK significantly enhanced osteogenic differentiation of bone mesenchymal stem cells, as evidenced by the significant improvement in alkaline phosphatase activity and mineral deposition. Moreover, the functional biointerfaces exhibited substantialantibacterial efficacy in vitro. Micro-computed tomography (micro-CT) and histological evaluation of rat tibia implantation showed that compared to uncoated screws, the PCBAA-functionalized PEEK screws significantly enhanced new bone formation and possessed superior pull-out strength. The findings of this study suggest that the one-step polymerization of PCBAA coatings on PEEK substrates is facile and can efficiently overcome the limitations of current surface modification. The resultant PCBAA-coated PEEK biointerfaces have shown great promise in promoting osseointegration and mitigating postoperative infections for clinical outcomes of PEEK-based orthopedic implants.
危险品化学品经营许可证（带存储）