Metal-Organic Frameworks/Heterojunction Structures for Surface-Enhanced Raman Scattering with Enhanced Sensitivity...

Area of Science:

• Materials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Metal-organic frameworks (MOFs) are promising for Surface-Enhanced Raman Scattering (SERS) due to tunable structures and high surface area.
• Current MOF-based SERS substrates lack sufficient sensitivity for ultrasensitive detection.
• Developing enhanced MOF structures is crucial for improving the limit of detection (LOD).

Purpose of the Study:

• To develop a novel MOFs/heterojunction structure for enhanced SERS detection.
• To achieve ultrasensitive detection with a lower limit of detection (LOD) compared to existing MOF substrates.
• To demonstrate the applicability of the developed SERS substrate in practical applications like medicine screening.

Main Methods:

• Fabrication of an in situ ZIF-67/Co(OH)₂ heterojunction on a nanocellulose paper (nanopaper) substrate.
• Characterization of the heterojunction structure and its SERS performance.
• Extension of the heterojunction strategy to other MOFs (e.g., HKUST-1) and application in medicine screening (omeprazole detection).

Main Results:

• The in situ ZIF-67 nanoplate achieved an LOD of 0.98 nmol/L for Rhodamine 6G with a Raman enhancement of 1.43 × 10⁷.
• The heterojunction structure demonstrated a 100-fold improvement in SERS performance compared to pure ZIF-67.
• The MOFs/heterojunction structure facilitated efficient photoinduced charge transfer, enhancing SERS detection capabilities.

Conclusions:

• The developed MOFs/heterojunction nanoplates represent a significant advancement in SERS substrate design for ultrasensitive detection.
• This approach offers tailorability and high anti-interference ability, providing versatile options for MOF-based SERS applications.
• The study highlights the potential of MOFs/heterojunctions for sensitive detection in fields like pharmaceutical analysis.