Nano–bio hybrid catalysts have emerged as a promising platform for sustainable energy conversion by integrating the high selectivity of enzymes with the structural robustness and conductivity of nanomaterials. In recent years, the growing demand for clean energy technologies has driven the development of biohybrid systems capable of efficient electron transfer, enhanced catalytic activity, and improved operational stability. This review comprehensively discusses the design principles, mechanistic foundations, and performance metrics of enzyme–nanomaterial interfaces for energy-related applications. We first outline the fundamentals of enzymatic redox catalysis and the limitations of free enzymes in practical systems. Subsequently, we examine the functional roles of nanomaterials including carbon-based materials, metal and metal oxide nanoparticles, and two-dimensional platforms such as MXenes in facilitating enzyme immobilization and promoting direct or mediated electron transfer. Special emphasis is placed on engineering strategies at the bio–nano interface, including immobilization techniques, surface functionalization, and structural tuning to optimize catalytic efficiency. The review further highlights representative hybrid systems based on laccase, glucose oxidase, peroxidase, and hydrogenase enzymes, and evaluates their applications in biofuel cells, solar–bio hybrid systems, green oxidation reactions, and self-powered biosystems. Stability challenges, deactivation mechanisms, and enhancement strategies such as polymer coatings, cross-linking, and nanoconfinement are critically analyzed. Finally, emerging directions including artificial enzymes, AI-guided catalyst design, and self-healing bioelectrodes are discussed to provide a forward-looking perspective on next-generation sustainable bioelectrocatalytic systems.

Triple-negative breast cancer (TNBC) is an aggressive and clinically heterogeneous breast cancer subtype characterized by the absence of estrogen receptor, progesterone receptor, and HER2 overexpression, limited targeted treatment options, early relapse, and frequent development of therapy resistance. Although TNBC often shows initial sensitivity to chemotherapy, durable responses are commonly undermined by the emergence of adaptive resistant cell states rather than solely by fixed genetic mutations. This review synthesizes the role of epigenetic plasticity as a central mechanism that enables TNBC cells to dynamically reprogram transcriptional identity, survive therapeutic stress, and transition between epithelial, mesenchymal, stem-like, immune-evasive, and drug-tolerant persister phenotypes. Key epigenetic mechanisms include aberrant DNA methylation, histone acetylation and methylation, BET/BRD4-dependent transcriptional regulation, EZH2-mediated repression, SWI/SNF-dependent chromatin remodeling, non-coding RNA networks, and three-dimensional genome reorganization. These processes regulate tumor suppressor silencing, DNA-damage repair, epithelial–mesenchymal plasticity, cancer stem-cell maintenance, metabolic adaptation, immune-checkpoint regulation, and minimal residual disease. The review also highlights the translational relevance of epigenetic biomarkers, including DNA methylation signatures, circulating epigenetic markers, chromatin-accessibility profiles, and single-cell epigenomic approaches for diagnosis, prognosis, therapy prediction, and monitoring resistance evolution. Finally, therapeutic strategies targeting epigenetic plasticity are discussed, including DNMT, HDAC, BET, EZH2, KDM, and LSD1 inhibitors, with emphasis on rational combination approaches involving chemotherapy, PARP inhibitors, immunotherapy, and metabolic targeting. Overall, epigenetic plasticity represents both a major driver of TNBC resistance and a therapeutically exploitable vulnerability, provided those future strategies account for tumor heterogeneity, adaptive cell-state transitions, biomarker-guided patient selection, and combination-based treatment design.

Pharmaceutical pollutants have emerged as a critical class of aquatic micropollutants due to their continuous release, persistence, and potential impacts on ecosystems and human health. Conventional wastewater treatment systems are often insufficient to achieve complete removal, necessitating the development of advanced oxidation processes (AOPs), such as Fenton and Fenton-like systems. These processes rely on the generation of reactive oxygen species (ROS), including hydroxyl radicals (•OH), superoxide species, singlet oxygen, and, in some heterogeneous systems, high-valent iron-oxo intermediates, which collectively enable the degradation of structurally diverse and recalcitrant pharmaceutical compounds. Recent advances have highlighted the pivotal role of nanomaterials as catalysts in enhancing Fenton-based processes. Nanostructured catalysts, including iron-based nanoparticles (NPs), metal oxides, carbon-based materials, and bimetallic composites, offer high surface area, tunable redox properties, and improved electron transfer, leading to enhanced catalytic efficiency and mineralization rates. Importantly, the integration of green synthesis approaches using plant extracts, microorganisms, and biopolymers provides environmentally benign routes for nanomaterial fabrication while introducing functional surface groups that improve catalytic performance. Mechanistically, pharmaceutical degradation in Fenton systems involves complex pathways driven by multiple ROS species, including •OH, superoxide radicals, and singlet oxygen, leading to the formation of intermediate products and eventual mineralization. However, challenges such as NP aggregation, metal leaching, incomplete mineralization, and potential toxicity of intermediates remain critical considerations. This review critically evaluates the occurrence of pharmaceutical pollutants, the fundamentals of Fenton and Fenton-like processes, and the design and application of green-synthesized nanomaterials as efficient catalysts. It further explores degradation mechanisms, operational parameters, and sustainability considerations, highlighting future directions for scalable, environmentally responsible water treatment technologies.

As demand for clean fuels increases, there is growing interest in catalytic technologies that combine the functional properties of enzymes with the robustness and flexibility of nanomaterials. Nevertheless, the term “nanozyme” is often used to describe nanoscale heterogeneous catalysts and electrocatalysts regardless of proof of enzyme-like activity, which complicates understanding of renewable-energy technology development. This review discusses the difference between nanozymes and conventional nanocatalysts using common criteria of structure, kinetics, and mechanisms, and provides the methodology for substituting enzymes with nanozymes for renewable fuels. The relevant catalytic systems are classified based on the natural enzymes they imitate, including hydrogenase-like nanozymes for production of hydrogen, laccase-like nanozymes used as cathodes of biofuel cells, hydrolase- and cellulase-like nanozymes for biomass saccharification, formate dehydrogenase-like nanozymes for the conversion of carbon dioxide to formate, and carbonic anhydrase-like nanozymes for hydration and capture of CO₂. In contrast, only nanoscale materials with features such as defect-mediated activity, surface adsorption, or electron-transfer enhancement are relevant to conventional catalysts unless other evidence simulating enzymatic processes has been presented. Enzymatic features, including enzyme-inspired coordination sites, enzyme-substrate cavities, relay organizations of protons, and spatial layouts of catalytic active sites, are main methods of improving the performance and efficiency of the catalyst. However, non-standard categorization of catalytic products, insufficient mechanistic justification of nanozymatic nature, no standardized ways of testing, high toxicity of materials, and limitations of scale-up affect the transfer of the product to the processing industries significantly. Therefore, a consolidated understanding of natural activation, catalyst design, catalytic mechanisms, and quantitative energy efficiency results in the creation of valid frameworks for the design of validated nanozymes in the area of environmentally friendly energy processing. The increasing global demand for sustainable energy has intensified the search for efficient, robust catalytic systems for renewable fuel production. At the same time, conventional catalysts, including natural enzymes and noble metal-based materials, continue to suffer from limitations such as poor stability, high cost, and limited scalability under industrial conditions. In this context, nanozyme-based catalysts have emerged as a promising alternative by integrating enzyme-like catalytic activity with the structural tunability, durability, and cost-effectiveness of nanomaterials. This review provides a comprehensive overview of recent advances in nanozyme-based catalysts for renewable fuel applications, beginning with the fundamental definition and classification of nanozymes based on their enzyme-mimicking activities. The review discusses mechanistic insights, emphasizing electron-transfer processes, active-site engineering, and catalytic pathways governing key energy reactions, including the hydrogen evolution reaction (HER), oxygen evolution and reduction reactions (OER/ORR), CO₂ reduction, and biomass conversion into biofuels. The role of diverse material platforms, including metal-based, carbon-based, and hybrid nanozymes, is critically analyzed in terms of catalytic efficiency, selectivity, and stability. In addition, recent developments in computational modeling, particularly density functional theory (DFT), are highlighted for their contribution to predictive catalyst design and atomic-level mechanistic understanding. Despite these advantages, challenges related to toxicity, scalability, and real-world applicability remain significant barriers. Overall, nanozymes represent a next-generation catalytic platform with strong potential for sustainable fuel production, and future research should focus on in situ and in operando characterization, rational material design, and integration with renewable energy systems to support their transition to industrial deployment.