One-step microwave-assisted ionothermal synthesis of AuNPs/CTF for sensitive surface-enhanced Raman spectroscopy detection

A one-step microwave-assisted ionothermal method (OSMAIM) was developed for the rapid synthesis of an AuNPs/covalent triazine framework (CTF) composite that integrates solid-phase extraction (SPE) with surface-enhanced Raman spectroscopy (SERS). In this method, ZnCl₂ acts as an ionothermal catalyst, facilitating rapid precursor trimerization and concurrent Au nanoparticle formation under microwave irradiation, thereby enabling efficient one-step synthesis. The resulting composite exhibits high porosity and strong SERS activity, enabling trace-level detection of target analytes. As a proof of concept, linear concentration ranges of 1.0–25 × 10⁻⁸ M for Victoria Blue (VB) and 5.0–100 × 10⁻⁸ M for Malachite Green (MG) were successfully established using the AuNPs/CTF composite. The corresponding detection limits were determined to be 0.56 nM (VB) and 0.47 nM (MG) through the 3σ methodology. This work presents a promising strategy for multifunctional SERS substrates with potential applications in environmental, food, and biomedical analysis. • One-step synthesis of AuNPs/CTF composite via microwave-assisted ionothermal method. • Dual-function AuNPs/CTF substrate integrates SPE and SERS for ultra-trace detection. • The AuNPs/CTF substrate offers sensitive, reproducible, and robust performance in real-sample analysis.