Synthesis and Characterization of GO/ZIF-67 Nanocomposite: Investigation of Catalytic Activity for the Determination of Epinine in the Presence of Dobutamine

Abstract

In this study, we prepared graphene oxide (GO)/ZIF-67 nanocomposites. Therefore, GO/ZIF-67 nanocomposites were used as a modifier on a screen-printed electrode (GO/ZIF-67/SPE) for studying the electrochemical behavior of epinine in phosphate buffer saline (PBS) at pH 7.0 with voltammetry techniques. The GO/ZIF-67/SPE showed greater electrocatalytic activities than the bare SPE. As a result, the GO/ZIF-67/SPE was utilized for additional electrochemical examinations. The epinine concentration determination was in the range 9.0 × 10−8 M to 5.0 × 10−4 M, and the limit of detection (LOD) as well as the limit of quantification (LOQ) equaled 2.0 and 6.6 nM, respectively. From the scan rate study, the oxidation of epinine was found to be diffusion-controlled, and the simultaneous detection of epinine and dobutamine were well achieved with the differential pulse voltammetric (DPV) technique. Moreover, the stability and reproducibility of epinine at the GO/ZIF-67/SPE was studied, and the use of the GO/ZIF-67/SPE to detect epinine and dobutamine in real samples was furthermore successfully demonstrated.

Interrogating Encapsulated Protein Structure within Metal–Organic Frameworks at Elevated Temperature

“…Diffractograms for both the biocomposites (BSA@ZIF-8 and BSA@ZIF-67) and pure MOFs (ZIF-8 and ZIF-67) were similar to each other and showed strong agreement with the simulated pattern (Figure a,d), as well as those previously reported in the literature for ZIF-8 and ZIF-67. , The biocomposite patterns were nearly identical to those of the pure ZIF, except for a slight decrease in the apparent signal-to-noise ratio. This behavior has been observed in other biocomposites formed from proteins and MOFs , and is likely caused by heterogeneous (i.e., anisotropic) incorporation of BSA within the host framework, resulting in mild disruption of the constructive scattering.…”

Cobalt–Nickel Layered Double Hydroxides on Electrospun MXene for Superior Asymmetric Supercapacitor Electrodes

“…To further confirm the formation of CoNi-LDH, the Raman scattering spectra of Co-MOF@MX-CNF and CoNi-LDH@MX-CNF are shown in Figure b . In addition to the peak at 258 cm –1 associated with MXene, new peaks have emerged at 219 cm –1 , 334 cm –1 , 380 cm –1 , and 683 cm –1 corresponding to the vibrational mode of the 2-methylimidazolate ligand and the Co–N bond. − This substantiates the successful synthesis of Co-MOF on MX-CNF. After the etching-deposition-growth process, the Raman peaks of the Co-MOF@MX-CNF precursor disappeared, and CoNi-LDH@MX-CNF exhibits a broad peak of the Ni-O/Co-O symmetric stretching mode at 525 cm –1 . , The characteristic peaks of the Co-MOF precursor are conspicuously absent in the Raman spectra of the resultant CoNi-LDH@MX-CNF, implying complete conversion of Co-MOF.…”

XRD and Spectroscopic Investigations of ZIF—Microchannel Glass Plates Composites

“…For the ZIF-67-1 sample, the peaks had an excellent match with the COD 4118891 database card, confirming that ZIF-67, Co(mIm) 2 , had been synthesised. ZIF-67-1 demonstrated excellent agreement with the previously published ZIF-67 material with the main peaks at index as 7.9° (011), 10.6° (002), 12.9° (112), 14.7° (022), 16.5° (013), 18.4° (222), 22.0° (114), 24.6° (233), 25.9° (002), 26.4° (134), 29.6° (044), 31.2° (244), and 32.3° (235) [ 41 ]. This ZIF phase corresponds to the SOD (sodalite-like) topology with high surface area [ 42 ].…”