Functionalized Metal-Organic Framework for Selective Fluorometric Detection of Sodium Dodecyl Sulfate and Vitamin B 12 Using MOF@Cotton Composites and Lewis Base-Catalyzed Condensation Reaction

• Published in: Inorganic chemistry 2023-06, Vol.62 (22), p.8605-8614
• Main Authors: Ghosh, Subhrajyoti, Krishnan, Jayaraman, Karthik, Veerappan, Dhakshinamoorthy, Amarajothi, Biswas, Shyam
• Format: Article
• Language: English
• Subjects: Lewis Bases; Metal-Organic Frameworks - chemistry; Sodium Dodecyl Sulfate; Vitamin B 12; Vitamins
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.3c00631

A zirconium(IV)-based metal-organic framework (MOF) fluorophore containing the 2,5-diaminoterephthalic acid (H BDC-(NH) ) linker was synthesized and characterized. The physicochemically stable, porous ( = 504 m g ) MOF ( ) exhibited selective and sensitive fluorescence turn-on behavior toward the sodium dodecyl sulfate (SDS) surfactant and turn-off response toward vitamin B . This is the first ever reported MOF-based dual optical sensor of SDS and vitamin B . Other competitive analytes did not interfere in the detection of both the analytes. Along with the lowest ever reported limit of detection (LOD) values (LOD for SDS = 108 nM and LOD for vitamin B = 45.3 nM), displayed short response time for SDS (50 s) and vitamin B (5 s) detection. The MOF was able to detect SDS in various real water samples and vitamin B in various bio-fluids (urine and serum) and pH media. A MOF-coated cotton composite was fabricated, which displayed a visible color change under UV light even after treating it with a nanomolar concentration of both the analytes. The sensor displayed excellent reusability up to five cycles of sensing. Various experimental outcomes evidenced that the electrostatic interaction between the -NH groups of the linker and the -SO group of SDS is the possible reason for the selective SDS sensing. For vitamin B , the energy transfer from the probe to vitamin B resulted in fluorescence quenching. In addition, the catalytic performance of was investigated in the condensation reaction between benzaldehyde derivatives with cyanoacetamide with high yields in ethanol at 70 °C. The solid was used for three cycles with no decrease in its activity and selectivity. PXRD and FESEM analysis before and after the reaction suggested the retention of the crystallinity of , thus indicating catalyst stability.