Metal–Organic Frameworks for Preserving the Functionality of Plasmonic Nanosensors

Abstract

Preserving the functionality of nanosensors is critical for their reliable performance under harsh environmental conditions. Biofunctionalized plasmonic nanostructures are an important class of bionanoconjugates for biosensing, bioimaging and nanotherapeutics. Plasmonic nanostructures and biomolecules exhibit poor thermal stability over time. Here, we report a class of metal organic framework, zeolitic imidazolate framework-8 (ZIF-8), as a protective coating for preserving plasmonic nanostructures and plasmonic bionanoconjugates at elevated temperature. Gold nanobipyramids (AuNBPs) with sharp tips are attractive plasmonic nanotransducers with high sensitivity but are prone to structural change and loss of sensitivity. This work reports the first observation that ZIF-8 can preserve the structure of AuNBPs, and corresponding strong electromagnetic field enhancement and high refractive index sensitivity. In addition, ZIF-8 coating enables nearly 100% retention of biorecognition capability of antibodies immobilized on the AuNBP surface after exposure to 60°C for 48 hours. The efficacy, versatility, and facile implementation of ZIF-8 coating offer great promise for the preservation of nanosensors.

Wearable plasmonic paper–based microfluidics for continuous sweat analysis

“…Antibodies were used for the specific detection of cortisol, a stress biomarker (19,22). However, enzymes and antibodies are prone to degrade over time and lose their functionality after exposure to harsh environments and contamination (23)(24)(25)(26). Therefore, continuous measurements of chemical analytes with high sensitivity, selectivity, and environmental stability remain challenging.…”

“…Up to date, substantial progress has been made in the fabrication of various SERS substrates to provide high sensitivity, uniformity, and stability for reliable quantification of analytes at a very low concentration (27,34). To further improve sample collection efficiency, flexible SERS substrates, such as plasmonic paper and foams, have been developed (24,26,(35)(36)(37)(38)(39)(40)(41)(42)(43). Recent works show that SERS offers highly sensitive and specific trace detection in sweat using silver nanowires or silver nanocubes as SERS substrates (35,36).…”

Self‐Assembly of Oriented Antibody‐Decorated Metal–Organic Framework Nanocrystals for Active‐Targeting Applications

“…[11][12][13][14][15] MOFs have been combined with Abs, either via encapsulation or site-specific conjugation, for biobanking and immunosensing applications. [11][12][13][16][17][18][19][20][21][22] For instance, [17] to protect the protein from temperature and solvents, Abs were encapsulated within zeolitic imidazolate frameworks (ZIFs [23] ). To improve biodetection, Abs were biotinylated on the COOHrich MOF surface.…”

Assembly of gold nanorods functionalized by zirconium-based metal–organic frameworks for surface enhanced Raman scattering

“…26 ZIF-8 coated Au nanobipyramids were presented as SERS probes for 4-aminothiophenol detection. 27 Although the SERS activity of MOF-encapsulated nanocrystals have been demonstrated, it remains challenging to create numerous plasmonic hotspots at the nanoparticle junctions while maintaining the MOF structures.…”