The surface of Ti3C2 MXene nanosheets (TC NSs) was first modified with the antioxidants sodium ascorbate (SA) and dopamine (DA) (DSTC NS) to improve their stability in oxidative and hydration environments and thereby improve their bioapplications. This novel approach not only improved MXene stability by arresting oxidation but also increased the available functional groups for further functionalization with various biomolecules. The DSTC NSs were then sequentially conjugated with enzyme glucose oxidase (GOx) and photosensitizer Ce6 to render the obtained CGDSTC NSs with glucose starvation and photodynamic therapeutic properties and thus attain high efficiency in killing cancer cells through the cooperative effect. The as-synthesized CGDSTC NSs demonstrated tremendous photothermal effect with conversion efficiency of 45.1% and photodynamic (ROS generation) properties upon irradiation with 808 and 671 nm lasers. Furthermore, it was observed that the enzymatic activity of CGDSTC NSs increased upon laser irradiation due to enhanced solution temperature. During in vitro studies, the CGDSTC NSs exhibited cytocompatability to HePG2 and HeLa cells under nonstimulus conditions. However, they elicited more than 90% cell-killing efficiency in the presence of glucose and laser irradiation via the cooperative effect between starvation therapy and phototherapy. These results indicate that CGDSTC NSs could be used as potential therapeutic agents to eradicate cancers with no or few adverse effects. This surface modification approach is also simple and facile to adopt in MXene-based research.

In this study, for the first time, red-emitting CsMg x Pb 1−x I 3 quantum dots (QDs) are prepared by doping with magnesium (Mg) ions via the one-pot microwave pyrolysis technique. The X-ray diffraction and X-ray photoelectron spectroscopy results have confirmed partial substitution of Pb 2+ by Mg 2+ inside the CsPbI 3 framework. The as-synthesized CsMg x Pb 1−x I 3 QDs have exhibited excellent morphology, higher quantum yield (upto ∼89%), better photostability and storage stability than undoped CsPbI 3 . Next, the bioavailability of as-synthesized hydrophobic CsMg x Pb 1−x I 3 QDs is improved by encapsulating them into gadolinium-conjugated pluronic 127 (PF127-Gd) micelles through hydrophobic interactions (PQD@Gd). The optical properties of perovskite quantum dots (PQDs) and the presence of Gd could endow the PQD@Gd with fluorescence imaging, magnetic resonance imaging (MRI), and phototherapeutic properties. Accordingly, the MRI contrasting effects of PQD@ Gd nanoagents are demonstrated by employing T 1 and T 2 studies, which validated that PQD@Gd nanoagents had superior MR contrasting effect with a r 2 /r 1 ratio of 1.38. In vitro MRI and fluorescence imaging analyses have shown that the PQD@Gd nanoagents are internalized into the cancer cells via a caveolae-mediated endocytosis pathway. The PQD@Gd nanoagents have exhibited excellent biocompatibility even at concentrations as high as 450 ppm. Interestingly, the as-prepared PQD@Gd nanoagents have efficiently produced cytotoxic reactive oxygen species in the cancer cells under 671 nm laser illumination and thereby induced cell death. Moreover, the PQD@Gd nanoagent also demonstrated excellent photocatalytic activity toward organic pollutants under visible light irradiation. The organic pollutants rhodamine b, methyl orange, and methylene blue were degraded by 92.11, 89.21, and 76.21%, respectively, under 60, 80, and 100 min, respectively, irradiation time. The plausible mechanism for the photocatalytic activity is also elucidated. Overall, this work proposes a novel strategy to enhance the optical properties, stability, and bioapplicability of PQDs. The multifunctional PQD@Gd nanoagents developed in this study could be the potential choice of components not only for cancer therapy due to dual-modal imaging and photodynamic therapeutic properties but also for organic pollutant or bacterial removal due to excellent photocatalytic properties.

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This paper is focused on the comparative study of cactus powder, Alum, and their combination of physiochemical analyses of water sample such as TDS, pH, conductivity, salinity, and turbidity using jar test. The result indicated that percentage removal of turbidity from turbid water sample increased from 23.9% to 54% and 28.46% to 58.2% as dose increased from 0.50 to 3.50 g for both cactus powder and Alum, respectively. Cactus powder also has a marginal effect on pH value (7.33 at 0.50 g, 7.49 at 1.50 g, 7.57 at 2.50 g, and 7.57 at 3.50 g) as compared to the usage of chemical coagulants (Alum). The salinity was increased from 0.4% to 0.69 % and 0.39% to 0.98% as the dose of cactus powder and Alum increased from 0.50 g to 3.50 g, respectively. The result revealed that cactus powder is more effective in pH upholding, TDS maintenance, and salinity removal than Alum, but their combination is the most effective in terms of turbidity removal, reduction of salinity, reduction of conductivity, and reduction of TDS and has a marginal effect on dissolved oxygen (DO) value. In conclusion, the combination of Alum and cactus powder is more effective for turbidity removal, salinity removal, and pH and conductivity upholding than either of them used individually.

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