MOF-Assisted Nanocellulose Paper-Based Platform for Multiple Surface-Enhanced Raman Scattering Detection

Area of Science:

• Materials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Metal-organic frameworks (MOFs) are promising for surface-enhanced Raman scattering (SERS) due to their high surface area and functionalizable interiors.
• Photoinduced charge transfer (PICT) between MOFs and analytes amplifies SERS signals.
• Previous MOF-based SERS substrates had limited detection ranges due to analyte-specific energy level requirements.

Purpose of the Study:

• To overcome the limitations of single MOF SERS substrates by developing a multi-MOF platform for broader analyte detection.
• To enhance SERS signal amplification and selectivity through strategic MOF combinations and junction engineering.

Main Methods:

• Synthesis of a ZIF-8/Zn(OH)2 n-n junction SERS substrate for improved electron trapping and electromagnetic enhancement.
• Development of a multi-MOF SERS platform by in situ incorporation of ZIF-8 and ZIF-67 on the same substrate.
• Independent operation of ZIF-8 and ZIF-67 systems under different incident light wavelengths for selective analyte detection.

Main Results:

• The ZIF-8/Zn(OH)2 substrate achieved a 4.44 nM limit of detection for methyl orange (MO).
• The multi-MOF platform successfully detected both MO and Rhodamine 6G (R6G) independently using different wavelengths.
• Demonstrated broadened analyte detection range while preserving MOF tailorability and selectivity.

Conclusions:

• The developed multi-MOF SERS platform enables simultaneous detection of multiple analytes, significantly expanding the application scope.
• Manipulating hot electrons in MOF-based systems offers a powerful strategy for high-performance SERS substrate design.
• This approach represents a significant advancement in creating versatile and efficient SERS sensors.