Novel composites of nano-metal–organic frameworks (IRMOF-3) and silver nanoparticles for the ultra-sensitive performance of SERS sensing and optical fiber modes

Rapid chemical detection of drugs of abuse in biological fluids such as blood and saliva is a concern within medicine and law enforcement. As an outcome, a label-free detection platform takes biological fluid samples with concentrations ranging from extremely high to very low. We obtained experimentally the limit of detection (LOD) of glycerol concentration, corresponding to a minimum resolvable refractive index of 3.4 × 10−7 RIU (refractive index unit). We applied the microfluidic device sensors to the quantitating concentration dopamine solutions. The experiment was recorded in real-time as the concentration of analyte injected exposed to the fiber core surface resulted in a sensitive change in optical power transmission. The presented sensors also exhibited reasonably good reproducibility and higher sensitivity, providing the LOD as 1.02 × 10−11 M. A relatively simple scheme procedure is proposed for the simultaneous detection and quantitative assessment of rhodamine B using surface-enhanced Raman spectroscopy with a limit of detection of 10−12 M and a relative standard deviation of 5.78% across a detection concentration range mainly from 10−5 M to 10−12 M. The obtained results demonstrate the potential of nano-metal–organic framework materials as large-area, label-free optical fiber sensors and SERS-based platforms for biomedical sensing and environmental applications. •The rapid and simple synthesis of IRMOF-3/Ag composites, the lack of equipment needed, and low cost.•The IRMOF-3 carrier's porous hollow allows the large load of Ag NPs to provide many "hot dots".•Ability Raman enhancement is demonstrated through limit of detection for rh B and MB at 10-12 M and 10-9 M, respectively.•IRMOF-3/Ag composites-base optic fiber sensor has sensitivity to dopamine molecules at 1.02 × 10-11 M.