Synergistic effect of MXene and Ag NP–decorated aligned Ag NWs on SERS

In this work, MXene and Ag nanoparticle (Ag NP)–decorated aligned Ag nanowires (Ag NWs) are applied to achieve surface-enhanced Raman scattering (SERS). MXene/Ag NP–decorated aligned Ag NWs based PDMS (polydimethylsiloxane) (MAAP) substrate is fabricated following the order of oil–water–air interfacial self-assembly of aligned Ag NWs, then surface modification of Ag NPs, and drop-casting of MXene last. The synergistic effect of MXene and Ag NP–decorated Ag NWs confers the MAAP substrate with high sensitivity, universality (limit of detection of 10⁻¹⁰ M for rhodamine 6G and crystal violet, 10⁻⁹ M for malachite green), and reproducibility. Based on the existence of PDMS, the MAAP substrate exhibits a good flexibility, and it maintains a high Raman activity after stretching and bending for 100 times. In addition, the surface covering MXene prevents Ag NWs decorated by Ag NPs from oxidation, which made the MAAP substrate still have a relatively high Raman activity. The fabricated MAAP substrate enriches the family members of MXene-based SERS substrates and displays an application value in SERS on irregular surfaces.