This work reports the fabrication of magnetite (Fe₃O₄) nanoparticles (NPs) coated with various biocompatible surfactants such as glutamic acid (GA), citric acid (CA), polyethylene glycol (PEG), polyvinylpyrrolidine (PVP), ethylene diamine (EDA) and cetyl-trimethyl ammonium bromide (CTAB) via co-precipitation method and their comparative inductive heating ability for hyperthermia (HT) applications. X-ray and electron diffraction analyses validated the formation of well crystallined inverse spinel structured Fe₃O₄ NPs (crystallite size of ~ 8–10 nm). Magnetic studies confirmed the superparamagnetic (SPM) behaviour for all the NPs with substantial magnetisation (63–68 emu/g) and enhanced magnetic susceptibility is attributed to the greater number of occupations of Fe²⁺ ions in the lattice as revealed by X-ray photoelectron spectroscopy (XPS). Moreover, distinctive heating response (specific absorption rate, SAR from 130 to 44 W/g) of NPs with similar size and magnetisation is observed. The present study was successful in establishing a direct correlation between relaxation time (~ 9.42–15.92 ns) and heating efficiency of each surface functionalised NPs. Moreover, heat dissipated in different surface grafted NPs is found to be dependent on magnetic susceptibility, magnetic anisotropy and magnetic relaxation time. These results open very promising avenues to design surface functionalised magnetite NPs for effective HT applications.

Wearable tear-based biosensors have garnered substantial interest for real time monitoring with an emphasis on personalized health care. These biosensors utilize major tear biomarkers such as proteins, lipids, metabolites, and electrolytes for the detection and recording of stable biological signals in a non-invasive manner. The present comprehensive review delves deep into the tear composition along with potential biomarkers that can identify, monitor, and predict certain ocular diseases such as dry eye disease, conjunctivitis, eye-related infections, as well as diabetes mellitus. Recent technologies in tear-based wearable point-of-care medical devices, specifically the state-of-the-art and prospects of glucose, pH, lactate, protein, lipid, and electrolyte sensing from tear are discussed. Finally, the review addresses the existing challenges associated with the widespread application of tear-based sensors, which will pave the way for advanced scientific research and development of such non-invasive health monitoring devices.

Antibacterial activity of nanoparticles (NPs) and nanocomposites (NCs) has received wide spread attention in biomedical applications. In this direction, the authors prepared zinc oxide (ZnO), iron oxide (Fe ₃ O ₄ ), and their composite including reduced graphene oxide (rGO) by hydrothermal method. The structural and microstructural properties of the synthesised NPs and NCs were investigated by XRD, FT‐IR, UV‐Vis, TGA, and TEM analysis. PEG‐coated ZnO and Fe ₃ O ₄ form in hexagonal wurtzite and inverse spinel structures, respectively. ZnO forms in rod‐shaped (aspect ratio of ∼3) morphology, whereas well‐dispersed spherical‐shaped morphology of ∼10 nm is observed in Fe ₃ O ₄ NPs. The ZnO/Fe ₃ O ₄ composite possesses a homogeneous distribution of above two phases and shows a very good colloidal stability in aqueous solvent. These synthesised particles exhibited varying antibacterial activity against gram‐positive strain Staphylococcus aureus (S. aureus) and gram‐negative strain Escherichia coli (E. coli). The nanocomposite exhibits a better cidal effect on E. coli when compared to S. aureus when treated with 1 mg/ml concentration. Further, the addition of rGO has intensified the anti‐bacterial effect to a much higher extent due to synergistic influence of individual components.

The pervasiveness of cancer is a global health concern posing a major threat in terms of mortality and incidence rates. Magnetic hyperthermia (MHT) employing biocompatible magnetic nanoparticles (MNPs) ensuring selective attachment to target sites, better colloidal stability and conserving nearby healthy tissues has garnered widespread acceptance as a promising clinical treatment for cancer cell death. In this direction, multifunctional iron oxide nanoparticles (IONPs) are of significant interest for improved cancer care due to finite size effect associated with inherent magnetic properties. This review offers a comprehensive perception of IONPs-mediated MHT from fundamentals to clinical translation, by elucidating the underlying mechanism of heat generation and the related influential factors. Biological mechanisms underlying MHT-mediated cancer cell death such as reactive oxygen species generation and lysosomal membrane permeabilization have been discussed in this review. Recent advances in biological interactions (in vitro and in vivo) of IONPs and their translation to clinical MHT applications are briefed. New frontiers and prospects of promising combination cancer therapies such as MHT with photothermal therapy, cancer starvation therapy and sonodynamic therapy are presented in detail. Finally, this review concludes by addressing current crucial challenges and proposing possible solutions to achieve clinical success.

The present paper reports about the superior performance of some amine-based proton sources in enhancing the photocatalytic efficiency of Fe₂O₃–TiO₂ composite during a water-splitting reaction. The band gap of the Fe₂O₃–TiO₂ catalyst is tuned to 2.3 eV by varying the Fe content. The heterojunctions generated in the photocatalyst facilitate effective charge carrier migration suppressing the electron–hole recombination rate. The enhanced photocatalytic activity of the catalyst is studied using an experimental setup comprising a solar simulator (AAA) and a hydrogen gas chromatograph. The effect of proton sources viz, aniline hydrogen chloride (AH), diethylamine hydrogen chloride (DAH) and triethylamine hydrogen chloride (TAH), on the photocatalytic performance of the catalyst is explored and studied in detail. These proton sources serve as electron donors that stimulate photogenerated electron–hole separation that results in high quantum efficiency of the Fe₂O₃–TiO₂ photocatalyst. A very high hydrogen generation rate of 880 μmol h⁻¹ is achieved with the DAH-assisted Fe₂O₃–TiO₂, whereas it is just 323 μmol h⁻¹ with the Fe₂O₃–TiO₂ alone. The enhancement in the hydrogen generation rate is attributed to the high basic nature, distinct hole scavenging action, low electron–hole recombination rate and the swift interfacial charge – transfer process. The effect of other proton source-assisted catalysts are also discussed in detail.