The development of superior functional enzyme mimics (nanozymes) is essential for practical applications, including point-of-care diagnostics, biotechnological applications, biofuels, and environmental remediation. Nanozymes with the ability to control their catalytic activity in response to external fuels offer functionally valuable platforms mimicking nonequilibrium systems in nature. Herein, we fabricated a supramolecular coordination bonding-based dynamic vesicle that exhibits multienzymatic activity. The supramolecular nanozyme shows effective laccase-like catalytic activity with a K M value better than the native enzyme and higher stability in harsh conditions. Besides, the nanostructure demonstrates an efficient peroxidase-like activity with NADH peroxidase-like properties. Generation of luminescence from luminol and oxidation of dopamine are efficiently catalyzed by the nanozyme with high sensitivity, which is useful for point-of-care detections. Notably, the active nanozyme exhibits dynamic laccase-mimetic activity in response to pH variation, which has never been explored before. While a neutral/high pH leads to the self-assembly, a low pH disintegrates the assembled nanostructures and consequently turns off the nanozyme activity. Altogether, the self-assembled Cu 2+based vesicular nanostructure presents a pH-fueled dissipative system demonstrating effective temporally controlled multienzymatic activity.

Covalent organic frameworks (COFs), also called “Organic Zeolites,” are crystalline porous organic polymers with robust and pre‐designable architecture and high crystallinity. They can be structurally controlled and functionally managed, due to the availability of diverse organic functionalities, covalent linkages and topologies. The current review briefly outlines their design strategies and comprehensively discusses their applications in the carbon‐carbon bond formation reactions. The reactivity of COF‐based catalysts with their homogeneous counterparts, catalyst stability, role of matrix, tailored organocatalysts and substituent effect on the reaction parameters, chemo‐/stereo‐/regioselectivity, shape/size selectivity are also discussed. Finally, the challenges and future prospects of functionalized COF‐based catalysts are discussed. These discussions will provide a better understanding of the role of COF‐based catalysts in the C−C bond formation and will also open doors to the design and synthesis of more robust, sustainable and benign catalytic systems, which might play a key role in organic synthesis and catalysis.

High internal phase emulsions (HIPEs) are non-equilibrium systems with distorted liquid droplet shapes consisting of high volume of internal phase (>74% v/v), enabling high loading of pharmaceutics and useful viscoelastic properties. Stability of the HIPEs is low and requires a high volume of surfactants in the continuous phase, which is environmentally unfriendly. Utilization of hydrogel as the continuous phase to stabilize HIPEs would offer a robust method to produce stable HIPE gels displaying reconfigurable and biocompatible properties, as well as access the huge repertoire of different biocompatible hydrogels. Herein, we introduce a new gel-immobilized HIPE (HIPEG) using chiral G-quadruplex (GQ) based hydrogel with external stimuli-responsive dual-drug release behavior, which is scarce for HIPEs. The hydrophilic and hydrophobic compartments of HIPEGs allow encapsulation of different drugs in both the compartments, with stimuli-responsive diffusion mediated release. Encapsulation of natural oils and antibiotics produces synergistic antimicrobial effects on both Gram positive (MRSA) and Gram negative (P. aeruginosa) bacterial strains. Moreover, we demonstrate biocatalytic reaction networks utilizing compartmentalized enzyme dyads. Notably, the ideal viscoelastic property of HIPEGs enables 3D bioprinting into different shapes, making the scaffold potential for tissue engineering applications. Altogether, our approach offers a one-step route to stimuli-responsive HIPE microcompartments immobilized in GQ hydrogels with endogenous reactivity and high viscoelasticity, and provides a viable step towards the development of biocompatible soft materials with tailorable functionality.

Keywords: Palladium, Sonogashira, Heterogeneous catalysis, supported nanoparticles