Synthesis of an IRMOF-1@SiO₂ Core–Shell and Amino-Functionalization with APTES for the Adsorption of Urea and Creatinine Using a Fixed-Bed Column Study

Kidney dysfunction is a clinical disease that disables the kidneys to remove the waste products and uremic toxins from the circulation and may lead to fatal kidney failure. Hemodialysis is advantageous in this circumstance since it prevents the accumulation of waste products in the body and facilitates the removal of uremic toxins. However, hemodialysis cannot entirely remove some uremic toxins, such as urea and creatinine. In this paper, a high-performance fixed-bed column for urea and creatinine removal was offered. As a result, a MOF layer was built on SiO2, which was then amino-functionalized using APTES. Numerous assays were used to characterize the final adsorbent. The adsorption of urea and creatinine was evaluated in batch and continuous conditions. Thus, it was demonstrated that the adsorption behavior of A(0.2)-IRMOF-1@SiO2 followed the Langmuir isotherm, and it exhibited the maximum adsorption capacity. The batch experiment determined that urea and creatinine had an adsorption capacity of 1325.73 and 625.00 mg·g–1, respectively. The adsorption capacity was increased, which was due to the presence of amino groups (APTES) on the MOF surface. The continuous operation was evaluated using the A(0.2)-IRMOF-1@SiO2 fixed-bed column. Thomas and Nelson’s models were examined to achieve a better understanding of the adsorption behaviors. The A(0.2)-IRMOF-1@SiO2 fixed-bed column successfully removed 92.57% of urea and 80.47% of creatinine. The separation factor for urea in comparison to creatinine was 2.40 in the A(0.2)-IRMOF-1@SiO2 fixed-bed column

Synthesis of GQD@ZIF-8 nano hybrids and its application as a lead optical sensor

The present study is aimed to investigate ZIF-8 metal organic frameworks, graphene quantum Dots, and their hybrid materials (GQD@ZIF-8) in the terms of sensing heavy metals. Brilliant property of graphene quantum Dots in fluorescence emission with a high intensity and ZIF-8 with high porosity and specific surface area (as adsorbent) were great stimulants to fabricate the aforementioned sensing system. The prepared hybrid material was successfully employed for the measurement of heavy metals such as lead in aqueous samples. The concentration of lead in various samples was measured using GQD@ZIF-8 hybrid materials via the method of single parameter during the time. In order to characterize GQD@ZIF-8 hybrid materials, Scanning Electron Microscopy (SEM), Furrier Transform Infrared spectroscopy (FT-IR), and nitrogen adsorption/ desorption (BET and BJH analysis) were employed in present study. Different parameters such as time, pH, and the concentration of adsorbent were also optimized in present study. The optimized values for concentration of adsorbent, time, and pH were found to be 0.05 mg/ml, 5 min, and 5 respectively. Importantly, limit of detection (LOD) for lead was calculated as 0.86 ppm. Low amount of LOD can be attributed to high fluorescence intensity and great specific surface area of the proposed sensor. The obtained results for LOD were compared with the other existing methods for detection of lead, presented in literature. The obtained results demonstrates that the proposed hybrid material possess high potential for detection and removal of lead from real samples

Prussian Blue Analogues-Derived Molecularly Imprinted Nanozyme Array for Septicemia Detection

Septicemia, a severe bacterial infection, poses significant risks to human health. Early detection of septicemia by tracking specific biomarkers is crucial for a timely intervention. Herein, we developed a molecularly imprinted (MI) TiO2–Fe–CeO2 nanozyme array derived from Ce[Fe(CN)6] Prussian blue analogues (PBA), specifically targeting valine, leucine, and isoleucine, as potential indicators of septicemia. The synthesized nanozyme arrays were thoroughly characterized using various analytical techniques, including Fourier transform infrared spectroscopy, X-ray diffraction, field-emission scanning electron microscope, and energy-dispersive X-ray. The results confirmed their desirable physical and chemical properties, indicating their suitability for the oxidation of 3,3′,5,5′-tetramethylbenzidine serving as a colorimetric probe in the presence of a persulfate oxidizing agent, further highlighting the potential of these arrays for sensitive and accurate detection applications. The MITiO2 shell selectively captures valine, leucine, and isoleucine, partially blocking the cavities for substrate access and thereby hindering the catalyzed TMB chromogenic reaction. The nanozyme array demonstrated excellent performance with linear detection ranges of 5 μM to 1 mM, 10–450 μM, and 10–450 μM for valine, leucine, and isoleucine, respectively. Notably, the corresponding limit of detection values were 0.69, 1.46, and 2.76 μM, respectively. The colorimetric assay exhibited outstanding selectivity, reproducibility, and performance in the detection of analytes in blood samples, including C-reactive protein at a concentration of 61 mg/L, procalcitonin at 870 ng/dL, and the presence of Pseudomonas aeruginosa bacteria. The utilization of Ce[Fe(CN)6]-derived MITiO2–Fe–CeO2 nanozyme arrays holds considerable potential in the field of septicemia detection. This approach offers a sensitive and specific method for early diagnosis and intervention, thereby contributing to improved patient outcomes