Green synthesis has gained a wide recognition as clean synthesis technique in the recent years. In the present investigation, silver nanoparticles were prepared by a novel green synthesis technique using Mangifera indica (Mango leaves) and found to be successfully used in dental applications. The prepared samples were spectroscopically characterized by XRD, PSA, SEM with EDS, and UV–Vis spectroscopy. The crystalline size and lattice strain were analyzed from the XRD data which were counter-verified by W–H plots and particle size analyzer. The XRD peaks revealed that average crystalline size of the as-synthesized Ag nanoparticles was of 32.4 nm with face-centered cubic structure. This was counter-verified by particle size analyzer and Williamson–Hall plots and found to be 31.7 and 33.21 nm in the former and latter, and the crystalline size of Ag NPs could be concluded as 32 ± 2 nm. The morphological structure of the prepared sample was studied through SEM images and the chemical composition was analyzed by the EDS data. The band energy was calculated as 393 nm from UV–Vis, which confirmed the synthesized sample as Ag nanoparticles. To improve the mechanical bonding and hardness of the dentally used glass ionomer cement (GIC), the synthesized silver nanoparticles were incorporated into GIC in 2% weight ratio. The morphology of the prepared specimens was studied using optical microscope images. Vickers microhardness and Monsanto hardness tests were performed on GIC, GIC reinforced with microsilver particles and GIC reinforced with nanosilver particles and the latter derived a promising results. The results of the Monsanto tests confirmed the increase in hardness of the GIC reinforced with AgNps as 14.2 kg/cm² compared to conventional GIC and GIC reinforced with silver microparticle as 11.7 and 9.5 kg/cm². Similarly the Vickers hardness results exhibited the enhanced hardness of GIC-reinforced AgNps as 82 VHN compared to GIC as 54 and GIC-reinforced silver microparticles as 61 VHN. The antibacterial activity of AgNPs was tested by a well-diffusion method on Escherichia coli and Staphylococcus aureus bacteria, and the obtained results exhibited a promising antibacterial activity of the as-synthesized nanoparticles.

In this work, MoO₃-CuO metal oxide composite nanopowders are prepared by simple mechanochemical assisted synthesis technique with the stoichiometric weight ratios of MoO₃ and CuO as 2.3:1 and 3.3:1, respectively. The structural and spectroscopic properties of the as-synthesised samples are characterised by XRD, SEM with EDS, FT-IR, Raman spectroscopy and TGA/DTA. X-ray diffraction pattern demonstrates the peaks correspond to orthorhombic phase of α-MoO₃ and monoclinic phase of β-CuO. The average crystalline sizes of the 2.3:1 and 3.3:1 samples were found to be 16 and 24 nm, respectively, which are supported by Williamson–Hall (W–H) calculations. The correlations between the milling rotational speeds with morphological characteristics are revealed by the SEM images. The fundamental modes of Mo=O and Cu–O were analysed by FT-IR. Raman analysis has provided the qualitative information about the structure of the mixed oxide composite. Thermogravimetry analysis and Differential Thermal Analysis (DTA) of MoO₃-CuO have revealed that the dual phase mixed oxide composite is stable up to 709 °C with a negligible weight loss. Based on the above, it can be inferred that the synthesised mixed lubricous oxide nanocomposite could be used as a solid lubricant at elevated temperatures.

Covid-19 still remains as global pandemic surging with different variants like alpha, beta, gamma, delta and most omicronin various countries resulted into SARS-CoV-2. An escalation in random testing for Covid-19 is considered as golden standard by World Health Organization (WHO) to control the spread of Corona virus. RT-PCR and nucleic acid hybridization strategies are the two highly sensitive outstanding tests used for the detection of SARS-CoV-2 in the DNA by the former and RNA/DNA by the later. Apart from the test for virus, antigen and antibodies other alternative hematological tests like CRP, Ferritine, IL-6, Blood Platelets and WBC and plasma became essential for the detection and management of Covid-19. Overcoming the limitations a rapid, efficient, low-cost and easy-to-implement test kits are in imperative need to meet the requirement. Electrochemical sensors are considered as potential, ultra-fast and point-of-care sensors used as self-testing kits. In this work, a meta review of various modified electrodes with different nanomaterials such as graphene, CNTs, and nano-dopants used as electrochemical sensors in association with testing various different parameters for detection of Covid-19. A detailed discussion on the merits and demerits of present testing patterns and scope of screen-printed electrochemical sensors modified with different nanomaterials and their advantages are presented.