Arvind Kumar

The unique physicochemical properties of ionic liquids allow them to interact specifically with the targeted analyte. When combined with the multifunctional features of MOFs, ionic liquids can enhance their efficacy for selective and precise detection. To our knowledge, sensors based on the integration of MOFs with ionic liquids are largely unexplored. Additionally, there exist numerous semiconductor-based sensors for H2S, yet fluorescence-based sensing remains a potential sensing pursuit. The present study introduces a sequential fluorescence nanosensor with augmented performance for both zirconium ions Zr(IV) and H2S developed from cadmium-based MOF (PUC-12) and ionic liquid trihexyl(tetradecyl)phosphonium bromide (IL1). Comprehensive characterization utilizing PXRD, TGA, HR-TEM, TRFS, FE-SEM, FT-IR analysis, etc., revealed the robust structural and functional attributes of PUC-12 and the nanocomposite (PIL-15). PIL-15 demonstrated remarkable selectivity and sensitivity (LOD = 0.25 μM; Ksv value = 0.24 × 106 M–1) for Zr(IV) ion detection in aqueous samples. The synergistic interplay of Zr(IV) and PIL-15 facilitated an innovative fluorescence-based turn “off–on–off” nanosensor for H2S (LOD = 1.7 μM; Ksv = 0.32 × 107 M–1), distinguishing itself from conventional semiconductor-based sensors. Mechanistic insights into the sensing processes were meticulously investigated using BET surface area analysis, XPS, and zeta potential analysis, providing a comprehensive understanding of the possible interactions. The nanosensor with a size of 33.14 nm demonstrated efficient stability (depicted by ICP-MS analysis) and sensing activities not only in aqueous media but also in H2S-responsive detection in a biological environment as well. The results were validated using RAW 264.7, an immortalized mouse macrophage cell line, achieving a detection limit (LOD) of 5.45 μM. A filter paper-based test was further performed, confirming the reliability and portability of the sensing platform. The functioning of the proposed sensor is illustrated through an IMPLICATION logic gate system. Additionally, the sensor exhibited potential for real-world applications by successfully detecting H2S in wine samples, emphasizing its versatility and practicality.

Microemulsions (MEs) comprising of cholinium dodecylbenzene sulphonate Cho[DBS], a bio‐based ionic liquid surfactant as an emulsifier, hydrophobic deep eutectic solvent (HDES) as nonpolar phase, and water as a polar component are constructed. Negative value of ∆G estimated from isothermal titration calorimetry (ITC) plots indicate spontaneous aggregation of Cho[DBS] both in water and HDES. The aggregates of Cho[DBS] in HDES and water show the critical micellar concentration (cmc) of ≈4.26 and ≈2.4 mMm, respectively. Cho[DBS] shows a better emulsifying capacity with a high monophasic region in the ternary phase diagram. MEs are utilized as nanoreactors for the sustainable synthesis of nano‐sized fluorescent carbon nanoparticles (FCNPs) with precise control over size and morphology. FCNPs are characterized using PXRD, Raman, XPS, HR‐TEM, UV–vis, and Fluorescence spectroscopic techniques. FCNPs exhibited remarkable properties viz. adjustable luminescence, good solubility, and biocompatibility. FCNPs are applied for fluorometric sensing of nitroaromatic compounds (NACs) and antibiotics through a quenching response originating from the inner filter effect, with a fast response nanomolar detection, and are found highly selective toward TNP (NAC), NFT, and NZF (antibiotics).

A MOF based eutectogel with antibacterial and antioxidant attributes, along with hemocompatibility, is used for the encapsulation and sustained release of curcumin.

Proteins are highly labile molecules, thus requiring the presence of appropriate solvents and excipients in their liquid milieu to keep their stability and biological activity. In this field, ionic liquids (ILs) have gained momentum in the past years, with a relevant number of works reporting their successful use to dissolve, stabilize, extract, and purify proteins. Different approaches in protein-IL systems have been reported, namely, proteins dissolved in (i) neat ILs, (ii) ILs as co-solvents, (iii) ILs as adjuvants, (iv) ILs as surfactants, (v) ILs as phase-forming components of aqueous biphasic systems, and (vi) IL-polymer-protein/peptide conjugates. Herein, we critically analyze the works published to date and provide a comprehensive understanding of the IL-protein interactions affecting the stability, conformational alteration, unfolding, misfolding, and refolding of proteins while providing directions for future studies in view of imminent applications. Overall, it has been found that the stability or purification of proteins by ILs is bispecific and depends on the structure of both the IL and the protein. The most promising IL-protein systems are identified, which is valuable when foreseeing market applications of ILs, e.g., in "protein packaging" and "detergent applications". Future directions and other possibilities of IL-protein systems in light-harvesting and biotechnology/biomedical applications are discussed.

Spirocyclic carbonates: A simple and efficient organocatalytic approach for the chemical fixation of CO ₂ with spiroepoxy oxindoles has been demonstrated. The catalytic protocol may provide additional possibilities to new applications.

Lignin is an amorphous, heterogeneous, aromatic biopolymer that is obtained from nature.

A waste-free chemical process involving comparatively greener solvents with recyclability is one of the desired goals of sustainable development. In this regard, task-specific ionic liquids (TSILs) emerge as groundbreaking solution, acting as both eco-friendly catalysts and reusable solvents in numerous industrial reactions. Herein, we exemplify the use of a family of phosphorus anion-based ionic liquids (ILs) having alkyl ammonium, pyridinium or lutidinium cations for successful isomerization of α-pinene oxide (APO) to industrially applicable trans-carveol with 74% selectivity and 99% conversion. This is the first time that we achieved isomerization of α-pinene oxide (APO) to trans-carveol with a very high selectivity as compared to campholeneic aldehyde in ionic liquid media. The mechanism for this conversion is well correlated with the physical properties (conductivity, density, molecular volume, standard entropy, and lattice energy) of the synthesized ionic liquids. The derived parameters from primary physical properties and Kamlet–Taft parameters provide strong support for greater reactivity and selectivity. The synthesized TSILs are chemically stable, easy to separate, and reusable for multiple runs without compromising the conversion of PO. The designed process fulfils the green metrics criteria by having 100% atom economy with an E-factor of 1.