A novel sensitive ACNTs–MoO2 SERS substrate boosted by synergistic enhancement effect

Abstract

Integrating chemical enhancement (CM) and electromagnetic enhancement (EM) into one substrate is of great significance, but as far as we know, little research has been done on this project. In this paper, the novel bead chain like acidified carbon nanotubes–MoO₂ (ACNTs–M) were designed by a simple two-step hydrothermal synthesis method. Benefitting from a good adsorption capacity, chemical enhancement and surface electromagnetic field enhancement effect, ACNTs–M exhibits a stunning SERS performance. The maximum enhancement factor (EF) of 5.13 × 10⁷ is obtained with R6G molecules on ACNTs–M. The limit of detection (LOD) of R6G is 10⁻¹⁰ M. In addition, ACNTs–M also exhibits SERS sensitivity of other organic dyes (CV, RhB and MB). The results of Raman signal enhancement mechanism research verified that the synergy of CM and EM is the reason for the high SERS sensitivity of ACNTs–M. We believe that our work may bring cutting edge of development of stable and highly sensitive nonmetal SERS substrates.