Advances in Science and Technology Vol. 117

Abstract: This paper reports the G-rich ssDNA for the colorimetric detection of cancer cells. The ssDNA-1 sequence has explored for the potential application of “Turn-On” colorimetric sensor for selective and sensitive detection of cancer cells. While complementary G-rich DNA strand form G-quadruplex with hemin molecule, which is more effective to catalyze the peroxidase mimicking activity towards TMB chromogenic substrate. The ssDNA-1 exhibits good selectivity for cancer cells. The colorimetric intensity of TMB was enhanced upon interaction of leukemic lymphoblasts cancer cells. The effect of pH has turned the selective sensing performances of the biosensor for detecting cancer cells with a lower detection limit of 0.54 nM, 0.18 nM, and 0.2 nM respectively.

Abstract: In this work, a diagnostic application was performed by utilizing magnetic nanoparticles for the bio-sensing. A novel Fe₃O₄ nanostructure was synthesized in this paper using a simple hydrothermal method, the Fe₃O₄ nanoparticles are successfully controlled to provide a more dynamic site for catalytic reaction. FTIR-analysis, scanning electron microscopy (SEM), X-ray diffraction (XRD) was used to examine the morphology of the synthesized nanoparticles. The findings showed that a unique Fe₃O₄ nanostructure was obtained nanoparticles confined in nanosphere. The relative catalytic kinetics of Fe₃O₄ nanostructure has followed Michaelis–Menten behaviours, according to an analysis of peroxidase-like activity. An effective approach for colorimetric sensing of glucose was formulated on the bases of efficient peroxidase-mimicking activity of Fe₃O₄ nanoparticles. The synthesized Fe₃O₄ nanoparticles are very hopeful for the application of bio-sensors.

Abstract: It's still a challenge to detect cholesterol more rapidly and easily. As a result, using a colorimetric sensor to detect cholesterol may result in the development of a ready-to-use. This research shows how a TiO₂ nanoparticles may be utilized as a peroxidase mimic to detect H₂O₂ and free cholesterol. The TiO₂ Nanoparticles was carefully studied in terms of structural, morphological, and functional characteristics. In the existence of cholesterol oxidase, and the proposed approach comprises detecting H₂O₂ produced during cholesterol oxidation. The TiO₂ nanoparticles sensor has shown good cholesterol detection sensitivity with a LOD as low as 0.061 M and a linear response in the 0.1 mM to 50 mM range.

Abstract: A colorimetric approach for the quantitative detection of H2S based on a NiO@r-GO composite was developed in this study and is simple, quick, and low-cost. Bimetallic porous material NiO@r-GO with iodide adsorption into their framework have been shown to boost catalytic activity. In this study, we present a new method for enhancing NiO@r-GO peroxidase-like activity. Comparatively, the kinetic measurements of NiO@r-GO demonstrate that it has a great affinity for substrates, facilitating electron transport, as opposed to HRP. Improvements in the activity of NiO@r-GO are attributable to the synergistic effect of the two compounds and to the speedy electron transfer process. This method is very sensitive for H₂S colorimetric technique with a LOD of 0.58 nM.

Abstract: In this study, we developed a carbon-dot-based sensor, which is particularly sensitive to ascorbic acid. It was possible to generate carbon dots (CDs) by utilising a renewable resource: Curcuma longa, which is abundantly available. The carbon dots produced from curcuma longa have particle diameters of 0.6 nm and are extremely brilliant in appearance. It has been proven that the fluorescence of carbon dots is inhibited in the presence of dopamine and ascorbic acid, with dopamine being more sensitive to the fluorescence than ascorbic acid. There were no significant differences between the minimal detection limits for dopamine and ascorbic acid, which were 33 μM, respectively. The Stern-Volmer plot was used to establish the quenching of ascorbic acid. It is one of the potential technique for sensing ascorbic acid.

Abstract: Patients must take significant doses of drugs to acquire the therapeutic effects required for disease therapy due to the absence of selectivity and accessibility of medicinal molecules. Drugs contain a range of drug carriers that are available to transport therapeutic chemicals to the targeted issues in the body. Mesoporous materials are choice for overcoming the aforementioned issues and producing effects in a predictable and long-term way. Because of its chemical characteristics, thermal stability, & biocompatibility, mesophoric nanoparticles are commonly utilized as release reagents. The innovative silica mesophore technology allows for efficient drug loading and administration after the target site has been reached. The additives used to manufacture MSNs can affect the property of mesoporous materials, including pore width, porosity, drug load, and surface characteristics. The need for an active surface provides for surface treatment as well as the coupling of therapeutic substances. They are widely employed in the bio-medical industry for diagnosis, target medication administration, bio-sensing, cellular absorption, and so on. The purpose of this study is, to sum up the existing level of information about mesoporous nanomaterials and their applications in diverse healthcare sectors.

Abstract: Mesoporous silica nanocomposite (MSNC) with a wall thick of around 10 nm were created using Fe₃O₄ nanoparticles as the inorganic template. In accordance with the results of SEM and BET analysis, MSNC were homogenous spherical particles with good dispersion, and their specific surface area it possible that Ibuprofen will become stuck within the MSNC carrier. Loading of drug shows a decline in a surface area from 225.08 to 69.25 m² g^-1, pore volume from 0.56 to 0.13cm g^-1 and the pore diameter from 7.96 to 6.74 nm correspondingly. The amount of Ibuprofen entrapped in the carrier was measured by UV spectroscopy and total glycerol (TG) measurement, respectively. It was determined pore size distribution of MSNC changed before and after Ibuprofen entrapment. The release profile of Ibuprofen from MSNC was characterised by a three-stage pattern with an influence on the time between each stage.