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In recent years, graphene-based materials complexed with drugs have been developed for application in cancer therapy, aimed at gaining synergistic effect. Here, we have prepared graphene oxide (GO) and graphene quantum dots (GQDs) with curcumin (Cur) in three different ratios (1:1, 1:3, and 1:5 w/v). We showed a successful complexation of GO and GQDs with Cur through various spectroscopy and microscopy techniques. The optical density of the complex through UV−vis spectroscopy showed less than 10% (for GQDs-Cur) and less than 20% (for GO-Cur) aggregation in 48 h, which confirms the stability of the complex. The UV−vis result estimates the loading efficiency of Cur to be 80 ± 1 and 83 ± 1% for GO-Cur and GQDs-Cur respectively. We tested the complexes GO-Cur and GQDs-Cur in different ratios as an anticancer drug against human breast cancer cell lines MCF-7 and MDA-MB-468 through the MTT assay. Following 48 h of incubation with the cell lines, a cell viability of more than 75% was observed in the case of GQDs & GO, while it was 40% in the case of Cur at a concentration of 100 μg/mL. The 1:1, 1:3, and 1:5 ratios of complexes enforced cell death ∼60, ∼80, and ∼95% at 100 μg/mL after 48 h of treatment, respectively. The optical images of cancerous cells treated with GO, GQDs, Cur, GO-Cur, and GQDs-Cur, at three different time intervals (0, 24, and 48 h), corroborated well with the results from the MTT assay in terms of the percentage of dead cells. The fluorescence images show a successful delivery of Cur drug inside the cancerous cell. The possible mechanism of killing of the cancerous cell with the complexes GO-Cur and GQDs-Cur is discussed. Moreover, this study opens a window to determine the mechanism of killing the cancerous cell.

Nanocrystalline Fe50Ni50 alloy is prepared using the sol-gel route in an amorphous silica host at different volume fractions (φ). The average particle size is 8.9 nm having log-normal distribution = 0.19, which is confirmed by transmission electron microscopy for φ = 1%. The blocking temperature (TB) is 30 K, as observed in dc magnetization. The frequency-dependent peak-shift in ac susceptibility satisfies Néel-Arrhenius formalism with more reasonable physical parameters than Vogel-Fulcher and dynamical scaling formalisms. Analysis of the relaxation dynamics below TB points toward weak interparticle interaction, signifying superparamagnetic behavior. Relaxation dynamics following stretched exponential function implies that it is involved with the activation against multiple anisotropy barriers, which is correlated to the distribution of particle size. Memory effects are observed in different experimental protocols below TB, which has been discussed pertaining to superparamagnetic behavior.

Self-assembled hierarchical nanostructures are slowly superseding their conventional counterparts for use in biosensors. These morphologies show high surface area with tunable porosity and packing density. Modulating the interfacial interactions and subsequent particle assembly occurring at the water-and-oil interface in inverse miniemulsions, are amongst the best strategies to stabilize various type of hollow nanostructures. The paper presents a successful protocol to obtain CeO2 hollow structures based biosensors that are useful for glucose to protein sensing. The fabricated glucose sensor is able to deliver high sensitivity (0.495 μA cm−2 nM−1), low detection limit (6.46 nM) and wide linear range (0 nM to 600 nM). CeO2 based bioelectrode can also be considered as a suitable candidate for protein sensors. It can detect protein concentrations varying from 0 to 30 µM, which is similar or higher than most reports in the literature. The limit of detection (LOD) for protein was ∼0.04 µM. Therefore, the hollow CeO2 electrodes, with excellent reproducibility, stability and repeatability, open a new area of application for cage-frame type particles.