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

Area of Science:

• Materials Science
• Analytical Chemistry
• Nanotechnology

Background:

• Integrating chemical (CM) and electromagnetic (EM) enhancement into a single substrate is crucial for advanced Surface-Enhanced Raman Spectroscopy (SERS).
• Limited research exists on substrates combining both CM and EM enhancement mechanisms.
• Development of stable and highly sensitive nonmetal SERS substrates is an ongoing challenge.

Purpose of the Study:

• To design and synthesize a novel substrate integrating CM and EM enhancement for superior SERS performance.
• To investigate the SERS capabilities of the new substrate for detecting organic dyes.
• To elucidate the enhancement mechanisms responsible for the observed SERS sensitivity.

Main Methods:

• A two-step hydrothermal synthesis method was employed to create bead chain-like acidified carbon nanotubes-MoO2 (ACNTs-M).
• The substrate's SERS performance was evaluated using various organic dyes, including R6G, CV, RhB, and MB.
• Raman signal enhancement mechanisms were analyzed to understand the synergistic effects of CM and EM.

Main Results:

• The ACNTs-M substrate demonstrated excellent SERS performance with a maximum enhancement factor (EF) of 5.13 × 10^7 for R6G.
• A low limit of detection (LOD) of 10^-10 M for R6G was achieved.
• The substrate exhibited high SERS sensitivity for other organic dyes, confirming its broad applicability.

Conclusions:

• The synergistic combination of CM and EM in ACNTs-M is responsible for its high SERS sensitivity.
• The developed ACNTs-M substrate shows significant potential for creating stable and highly sensitive nonmetal SERS platforms.
• This work contributes to advancing the field of SERS by offering a novel, high-performance substrate.