Functionalized silver nanoparticles for SERS amplification with enhanced reproducibility and for ultrasensitive optical fiber sensing in environmental and biochemical assays

Abstract

Silver nanoparticles for SERS amplification with enhanced reproducibility and for ultrasensitive optical fiber sensing in a biochemical assay.

Stacking‐order Reversed Multilayers of ZIF‐8 and Silver Nanoparticles for the SERS Detection of Organic Dye Species

“…This implies that ZIF‐8 is the outermost layer of Ag/ZIF‐8 multilayer SERS substrates, which protects the Ag layer from oxidation when stored in the air and improves their stability for detecting target molecules. Furthermore, the stability of the Ag/ZIF‐8 multilayer was found to be greater than that of the SERS substrates based on the Ag single‐layer, which had previously been examined [53] …”

“…The presence of identical peaks in the Ag/ZIF-8 samples indicates that the Ag NPs were successfully produced, with the peaks at 2q as 38.15°and 44.36°corresponding to planes (111) and ( 200). [53] The area under the Ag peak of the Ag/ZIF-8 structure is significantly reduced compared to the reverse structure due to the presence of secondary species (ZIF-8) on the covered surface, but no significant changes deviated in the peaks.…”

“…The appearance of strong peaks in two structure samples indicates that the produced ZIF‐8 has high crystallinity, which is consistent with previous studies, [47,52] where the peaks at 2$${\theta }$$ as 7.30, 10.35, 12.70, 14.80, 16.40, and 18.00° correspond to planes (110), (200), (211), (220), (310), and (222), respectively (Figure 2c–d). The presence of identical peaks in the Ag/ZIF‐8 samples indicates that the Ag NPs were successfully produced, with the peaks at 2$${\theta }$$ as 38.15° and 44.36° corresponding to planes (111) and (200) [53] . The area under the Ag peak of the Ag/ZIF‐8 structure is significantly reduced compared to the reverse structure due to the presence of secondary species (ZIF‐8) on the covered surface, but no significant changes deviated in the peaks.…”

“…Proton exchange between the Zn complex and the hydroxyl groups on the glass surface, [74,75] then the ZIF‐8 crystals film has grown since imidazole deprotonated to interact with Zn 2+ ions onto the surface after 1 hour of soaking [76,77] . According to our research reports, Ag NPs were fixed on the sample for 2 hours by strong electrostatic attractive force, then establishing the ZIF‐8/Ag structure [53] . The OH‐modified glass surface, on the other hand, was studied in the transformation to the functional group amine (−NH 2 ) by 3‐aminopropyltriethoxysilane [78,79] .…”

“…Finally, the mixture was washed repeatedly with methanol using centrifugation at 8500 rpm for 5 minutes and then dried under a vacuum. The preparation of Ag NPs by chemical reduction is described in detail in [53] …”