Gold nanoparticles are capped under the IRMOF-3 platform for in-situ surface-enhanced Raman scattering technique and optic fiber sensor

Integrating noble-metal and organic-inorganic hybrid crystalline porous materials for Raman signal augmentation is crucial for surface-enhance Raman spectroscopy. This study effectively generated gold nanoparticles / metal-organic frameworks (Au NPs/IRMOF-3) hybrids. The activity of Au NPs/IRMOF-3 double component substrate was significantly enhanced under localized surface plasmon resonance (LSPR) because the hot electrons produced on Au NPs surface were incorporated with IRMOF-3 and utilized the porous structure to capture the analyte. Development much hot spots of great significance for surface-enhanced Raman scattering (SERS) technique, herein, we developed an Au NPs/IRMOF-3-based nanosensor for rhodamine B (RhB) sensing by using in-situ SERS technique. X-ray diffraction (XRD) spectrometry, surface morphology analysis, optical properties, and energy-dispersive X-ray (EDX) spectroscopy were used to examine the layer-by-layer deposited substrate. The Au NPs/IRMOF-3 multilayers generated chemical and electromagnetic amplification of Raman signals of Rhodamine B at a low concentration and high enhancement factor. In the presence of dopamine molecules, due to the strong specific affinity between the modified surface out-layer of fiber sensor and the target molecules, resulting in the obvious change of the optical power transmission signals, which can be used for dopamine sensing with high sensitivity and stability (limit of detection is 1.42 × 10 -18 M with a wide linear range from 10 -17 to 6 × 10 -8 M of dopamine). The Au NPs/IRMOF-3 nanosensor can be used as an ideal platform for real applications, especially for some gases or low-weight molecules in the future. • Using a traditional synthesis approach, low cost, and high synthesis efficiency. • This sensor has high homogeneity and a stable arrangement structure. • Determination of Rhodamine B at low detection limit of 10 -9 M along with an enhancement factor of 6.54 × 10 9 . • Limit of detection is 1.42 × 10 -18 M and measurement range with a linear response from 10 −17 to 10 −8 M.