Ligand‐Driven Annular‐Epitaxial Growth of CuS‐Au Heterostructures as Trinity Plasmonic Nanozyme for Multimode Diagnosis of Pathogenic Bacteria

Abstract

Abstract This study presents a novel method to control the site‐selective growth of Au nanostars on CuS nanodisc substrate, it indicates that the surfactant ligands play a key role in the architecture control, only CTAC and homologous series with appropriate affinity to CuS can direct the annular‐epitaxial growth of Au nanoparticles on the CuS, which demonstrates superior peroxidase (POD)‐mimic and SERS activity. Mechanistic studies indicate that plasmon‐enhanced catalytic and SERS activity can be attributed to the spatially separated CuS‐Au heterostructure, which supports the light‐triggered hot electron‐hole pairs production and localized surface plasmon resonance hotspots. For practical biosensing, the CuS‐Au heterostructures assembled lateral flow assay (LFA) was used for SERS/catalytic colorimetric/photothermal three‐mode detection of Streptococcus pneumoniae and Klebsiella pneumoniae, with visually colorimetric mode at 103 CFU/mL and quantitative SERS/photothermal modes at 2–102 CFU/mL within 15 min, 15 clinical samples were used to validate the assay, the result was 100% concordant to the results of quantitative real‐time PCR. This study provides a unique avenue to controllably produce plasmon‐enhanced nanozyme, which can provide multi‐mode signals for LFA application and meet the requirements of different scenarios.

Keywords

• annular‐epitaxial growth
• CuS‐Au heterostructures
• ligand‐driven
• multimode diagnosis of pathogenic bacteria
• trinity plasmonic nanozyme