Measurement of Human Urine Specific Gravity Using Nanoplasmonics: A Paradigm Shift from Scales to Biosensors

Urine Specific Gravity (U SG ) is a direct indicator of the osmolarity of the urine and therefore it can be considered as a nonspecific marker of several underlying diseases which result in changes in hydration levels of the body. Here, a biosensor based on the principle of localized surface plasmon resonance (LSPR) is developed, which utilizes its refractive index sensing properties to measure U SG with a sensitivity of 79.21 nm U SG −1unit. Additionally, the sensor can measure the serum protein content within the urine. Traditionally, handheld refractometers are used to measure U SG which are operated as calibrated refractive index scales rather than a sensor. A simple experiment demonstrating the advantage of a sensor over scale, with LSPR as the transduction method, is also conducted to highlight the enhanced sensitivity of a sensor over a scale. Finally, analysis of results with an unsupervised machine learning algorithm, principal component analysis (PCA), demonstrate the feasibility of automating or perhaps adding artificial intelligence to such sensors, thereby exemplifying a potential paradigm shift from refractive index scales to sensors in U SG measurement

Study of Daucus carota ssp. Sativus and Butea monosperma to analyse their Applicability in Pharmaceutical Industry as Antimicrobial Agents

Human Beings have been using plant products to heal the Wounds and Diseases from the inception of humankind. Even when it was not known that microorganisms exist, People have been using antimicrobial agents prepared from plants. These antimicrobial products were prepared by extracting the plant in a suitable solvent. Antimicrobial property is conferred to plants by the presence of various phytochemicals which are the products of several Secondary metabolic pathways. The aim of this project was to decipher the potential use of Daucus carota ssp. Sativus and Butea monosperma in the pharmaceutical industry. In this research, Qualitative phytochemical screening and antimicrobial potential of Black carrot and Kamarkas has been studied.Black carrot showed good antimicrobial activity against A. brasiliensis, E. coli and S. enterica, arranged in descending order of the Slope obtained in each antimicrobial assay. Phytochemical screening showed the presence of Flavonoids, Soluble Phenolic Compounds, Naphthoquinone and traces of Saponins and Alkaloids. The Kamarkas showed antimicrobial activity against S. aureus and to some extent against A. brasiliensis. Phytochemical analysis of Kamarkas showed positive for all phytochemicals.

Refractive Index-Modulated LSPR Sensing in 20–120 nm Gold and Silver Nanoparticles: A Simulation Study

Localized surface plasmon resonance (LSPR) based sensing has been a simple and cost-effective way to measure local refractive index changes. LSPR materials exhibit fascinating properties that have significant implications for various bio/chemical sensing applications. In many of these applications, the focus has traditionally been on analyzing the intensity of the reflected or transmitted signals in terms of the refractive index of the surrounding medium. However, limited simulation work is conducted on investigating the refractive index sensitivity of LSPR materials. Within this context, here we simulate the refractive index sensing properties of spherical gold (Au) and silver (Ag) nanoparticles ranging from 20–120 nm diameter within 1.0 to 1.50 refractive index units (RIU). After analyzing the peak optical efficiency and peak wavelength, we report the sensing performance of these materials in terms of sensitivity, linearity and material efficiency, which we refer to as the figure of merit (FOM). Overall, our observations have revealed greatest FOM values for the smallest sized nanoparticles, a FOM of 6.6 for 20 nm AuNPs and 11.9 for 20 nm AgNPs with refractive index of 1

Measuring the Radius of Gyration and Intrinsic Flexibility of Viral Proteins in Buffer Solution Using Small-Angle X-ray Scattering

Measuring structural features of proteins dispersed in buffer solution, in contrast to crystal form, is indispensable in understanding morphological characteristics of the biomolecule in a native environment. We report on the structure and apparent viscosity of unfolded α and β variants of SARS-CoV-2 spike proteins dispersed in buffer solutions. The radius of gyration of the β variant is found to be larger than that of the α variant, while the ab initio computation of one of the possible particle-like bodies is consistent with the small-angle X-ray scattering (SAXS) profiles resembling a conformation similar to the three-dimensional structure of the folded state of the corresponding α and β spike variant. However, a smaller radius of gyration with respect to the predicted folded state of 2.4 and 2.7 is observed for both α and β variants, respectively. Our work complements the structural characterization of spike proteins using cryo-electron microscopy techniques. The measurement/analysis discussed here might be useful for quick and cost-effective evaluation of several protein structures, let alone mutated viral proteins, which is useful for drug discovery/development applications