Showing papers by "Kishor Kumar Sadasivuni published in 2023"

An Advanced Quaternary Composite for Efficient Water Splitting

Abstract: Abstract Electrochemical water splitting is a promising pathway for effective hydrogen (H 2 ) evolution in energy conversion and storage, with electrocatalysis playing a key role. Developing efficient, cost-effective and stable catalysts or electrocatalysts is critical for hydrogen evolution from water splitting. Herein, we evaluated a graphene-modified nanoparticle catalyst for hydrogen evolution reaction (HER). The electrocatalytic H 2 production rate of reduced graphene oxide-titanium oxide-nickel oxide-zinc oxide (rGO–TiO 2 –NiO–ZnO) is high and exceeds that obtained on components alone. This improvement is due to the presence of rGO as an electron collector and transporter. Moreover, a current density of 10 mA/cm 2 was recorded at a reduced working potential of 365 mV for the nanocomposite. The electronic coupling effect between the nanoparticle components at the interface causes the nanoparticle's hydrogen evolution reaction catalytic activity. Graphical Abstract

Nonenzymatic electrochemical lactic acid sensor using CuO nanocomposite

Abstract: The detection of biochemical performance and health parameters using wearable sensors have gained more attention. Lactic acid (LA) sensor was developed using the simple facile method for electrochemical detection in artificial sweat. The non-enzymatic LA sensing characteristics were assessed using cyclic voltammetry and amperometry response with a three-electrode system. The CuO nanoparticles were applied to a glassy carbon electrode (GCE) as a single-step modification using the Nafion matrix. In order to examine the CuO material used to modify the glassy carbon electrode, various analytical methods were used such as Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible spectroscopy (UV–Visible), and X-ray powder diffraction (XRD). The minimum detectable concentration for lactic acid was found to be 0.05 × 103 mol/l. The present investigation provides an excellent pathway for the specific detection of LA biomolecule for medical purposes by a non-enzymatic approach.

Aluminium doped ZnO nanostructures for efficient photodegradation of indigo carmine and azo carmine G in solar irradiation

Abstract: Abstract Aluminium doped zinc oxide (AZO) nanomaterials (Al x Zn 1-x O) with x fraction varying as 0.02 and 0.04 were synthesized using the auto-combustion method using glycine as a fuel. The synthesized catalysts were characterized with X-ray diffraction (XRD), UV–Visible Spectroscopy (UV–Vis), Raman spectroscopy, Photoluminescence (PL) spectroscopy, and High Resolution Transmission Electron Microscopy (HR-TEM). XRD results showed that synthesized materials possessed good crystallinity, while UV–VIS was employed to find the band gaps of synthesized materials. Raman was used to determine the vibrational modes in the synthesized nanoparticles, while TEM analysis was performed to study the morphology of the samples. Industrial effluents such as indigo carmine and azo carmine G were used to test the photodegradation ability of synthesised catalysts. Parameters such as the effect of catalyst loading, dye concentration and pH were studied. The reduction in crystallite size, band gap and increased lattice strain for the 4% AZO was the primary reason for the degradation in visible irradiation, degrading 97 and 99% equimolar concentrations of indigo carmine and azo carmine G in 140 min. The Al doped ZnO was found to be effective in faster degradation of dyes as compared to pure ZnO in presence of natural sunlight.

A practical perspective for chromatic orthogonality for implementing in photolithography

Abstract: Abstract Theoretically, it is more challenging to anticipate the conversion and selectivity of a photochemical experiment compared to thermally generated reactivity. This is due to the interaction of light with a photoreactive substrate. Photochemical reactions do not yet receive the same level of broad analytical study. Here, we close this research gap by presenting a methodology for statistically forecasting the time-dependent progression of photoreactions using widely available LEDs. This study uses NiS/ZnO in perovskite (MAPbI 3 ) solar cells as an additive (5 volume %). The effect of monolithic perovskite solar cells (mPSCs) on forecasting the wavelength of LEDs has been carefully investigated using various characterization methods, including X-ray diffraction (XRD) and Transmission electron microscopy (TEM). The photocatalytic activity was analyzed by measuring the voltage produced. Various factors like selectivity, stability and sensitivity were also examined. This work provides a new perspective to validate NiS/ZnO photocatalysts for predicting the wavelength of different light sources and to apply in photolithography.

Design and Development of Inexpensive Paper-Based Chemosensors for Detection of Divalent Copper.

Abstract: Abstract Simple, portable, and low-cost paper-based sensors are alternative devices that have the potential to replace high-cost sensing technologies. The compatibility of the paper base biosensors for both chemical and biochemical accentuates its feasibility for application in clinical diagnosis, environmental monitoring, and food quality monitoring. High concentration of copper in blood serum and urine is associated with diseases like liver diseases, carcinomas, acute and chronic infections, rheumatoid arthritis, etc. Detection of copper concentration can give an early sign of Alzheimer disease. Apart from that genetic Wilson's disease can be detected by evaluating the concentration of copper in the urine. In view of the above advantages, a novel and the highly sensitive paper-based sensor has been designed for the selective detection of Cu 2+ ions. The fast and highly sensitive chemiresistive multi-dye system sensor can detect Cu 2+ ions selectively in as low as 2.23 ppm concentration. Least interference has been observed for counter ion in the detection of Cu 2+ . Copper chloride, nitrate, and acetate were used to validate the detection process. This assay provides a very high selectivity of Cu 2+ ion over other metal cations such as Na + , Mg 2+ , Ca 2+ , etc. The easy preparation and high stability of dye solutions, easy functionalization of the paper-based sensors, high selectivity over other cations, low interference of counter anion, and significantly low detection limit of 2.23 ppm make it an effective Cu 2+ ion sensor for real-time application in near future. Graphical Abstract

A paper-based colourimetric sensor for sodium sulfite detection in beverages

Abstract: Abstract Sulfite is a common food additive that prevents oxidation from damaging food nutrients, and it has long been used in the food industry as a bleaching agent. It can harm the human body if taken wrongly or excessively. In this study, three dyes (cresol red, chlorophenol red, and bromocresol green) were explored to analyze the presence of sodium sulfite (SS) in an inexpensive, disposable paper sensor with a lower visible detection limit of 0.05 M. This visual paper sensor detects sodium sulfite with high selectivity and sensitivity at room temperature. An IoT-based sensor was also developed to practically apply the developed method, which is rapid and low-cost and can replace heavy-duty instruments. Both these sensors can substantially impact scenarios such as food quality monitoring and detecting sodium sulfite in medicinal items. Graphical Abstract

Exploration of spectroscopic, computational, fluorescence turn-off mechanism, molecular docking and in silico studies of pyridine derivative

Abstract: The present work reports pyridine-based chalones using spectroscopic techniques to use pyridine derivative analysis. The solvatochromic behavior of 3DPP in non-polar, polar protic and aprotic solvents has been investigated experimentally. The photophysical property of the compound in diverse solvents is attributed to the intra-molecular charge transfer interactions. The dipole moment of 3DPP is estimated theoretically and experimentally using various solvatochromic methods. It is observed that there is a bathochromic shift in the emission spectra of 3DPP, which confirms the π → π* transition. Fluorescence quenching of 3DPP is studied. The type of fluorescence quenching mechanism is found to be collisional quenching. A study of FRET theory on 3DPP was carried out with metal ions. There is a considerable energy transfer between 3DPP and metal ions. NLO behaviors of the compound have been revealed with the help of Kurtz-Perry powder technique. Additionally, the title molecule is docked, carried ADMET studies and drug-like activity using in silico tools. It is probed for antifungal activity through bioinformatics kit which showed potential information.

Stability and thermophysical properties enhancement of Al2O3-water nanofluid using cationic CTAB surfactant

Abstract: Excellent thermal characteristics of homogeneous dispersion of nano-sized particles in a carrier fluid (nanofluid) make it appealing for use in a variety of thermal applications. The study aims to prepare stable aqua-Al2O3 nanofluid utilizing a two-step method. To increase nanofluid stability, a cationic surfactant called cetyltrimethylammonium bromide (CTAB) is used. The carrier fluid is heated while magnetic stirring is used to increase nanoparticle distribution. Bath sonication with concurrent heating and probe sonication is used to improve long-term stability. The chemical composition of γ-Al2O3 was confirmed by X-ray diffraction (XRD) results, and Scanning Electron Microscopy (SEM) images revealed the shape and mean size of the particles. The stability of the synthesized sample is evaluated utilizing a variety of stability evaluation techniques, including visual examination, UV-vis spectrometry, and Dynamic Light Scattering (DLS), at various time intervals, including 1, 8, 15, and 30 days. After 15 days of manufacture, the stability of the nanofluid without surfactant was low. Due to improved particle suspension, nanofluid with surfactant has demonstrated greater UV-vis light absorption. After a month of synthesis, it was discovered that the mean particle sizes of suspended nanoparticles in carrier fluid were 80 nm and 536 nm for nanofluid with and without surfactant respectively. KD2Pro thermal analyzer and viscometer were used to measure the thermal conductivity and viscosity of nanofluid. As per the experimental results, a nanofluid's thermophysical characteristics were found to be improved with volume concentration of nanofluid. Maximum augmentation in thermal conductivity and dynamic viscosity is 8.5% and 76.2% respectively at 1% nanofluid volume concentration.

Revealing the improved sensitivity of PEDOT:PSS/PVA thin films through secondary doping and their strain sensors application

Abstract: The field of strain sensing involves the ability to measure an electrical response that corresponds to a strain. The integration of synthetic and conducting polymers can create a flexible strain sensor with a wide range of applications, including soft robotics, sport performance monitoring, gaming and virtual reality, and healthcare and biomedical engineering. However, the use of insulating synthetic polymers can impede the semiconducting properties of sensors, which may reduce sensor sensitivity. Previous research has shown that the doping process can significantly enhance the electrical performance and ionic conduction of conducting polymers, thereby strengthening their potential for use in electronic devices. However the full effects of secondary doping on the crystallinity, stretchability, conductivity, and sensitivity of conducting polymer blends have not been studied. In this study, we investigated the effects of secondary doping on the properties of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)/poly(vinyl alcohol) (PEDOT:PSS/PVA) polymer blend thin films and their potential use as strain sensors. The thin films were prepared using a facile drop-casting method. Morphology analysis using profilometry and atomic force microscopy confirmed the occurrence of phase segregation and revealed surface roughness values. This evidence provided a comprehensive understanding of the chemical interactions and physical properties of the thin films, and the effects of doping on these properties. The best films were selected and applied as sensitive strain sensors. EG-PEDOT:PSS/PVA thin films showing a significant increase of conductivity values from the addition of 1 vol% to 12 vol% addition, with conductivity values of 8.51 × 10−5 to 9.42 × 10−3 S cm−1. Our 12% EG-PEDOT:PSS/PVA sensors had the highest GF value of 2000 too. We compared our results with previous studies on polymeric sensors, and it was found that our sensors quantitatively had better GF values. Illustration that demonstrates the DMSO and EG dopant effects on PEDOT:PSS structure through bonding interaction, crystallinity, thermal stability, surface roughness, conductivity and stretchability was also provided. This study suggests a new aspect of doping interaction that can enhance the conductivity and sensitivity of PEDOT:PSS for device applications.

Oxide Derived Cu Nanofibril Assembly for Enhanced Nonenzymatic Glucose Sensing

Abstract: In this report, we have prepared copper nanofibril assembly via thermal oxidation followed by electrochemical reduction processes, exhibiting superior glucose detection ability. The morphological analysis evidenced the formation of rough islands or nanofibril structure on the Cu surface depending on initial thermal oxidation temperature. The glucose detection performance was investigated by performing cyclic voltammetry and chronoamperometry with varying glucose concentration. A high sensitivity (4131.57 μA mM−1 cm−2), low detection limit (1.41 μM), wider linear range (0–3.9 mM) and long–term stability (30 days) have been recorded for electrode thermally oxidized at 400 °C followed by electrochemical reduction process (rCu_400). The sensitivity is almost three times higher in comparison to the planner Cu surface. This significantly enhanced glucose sensing ability rCu_400 has been attributed to the nanofibril morphology, origination of Cu (111) facet and formation of a stable oxide layer evidenced by scanning electron microscopy, X-ray diffraction and energy dispersive spectroscopy analysis. Despite higher sensitivity, rCu_400 electrode does not show any response to the chloride ion, dopamine, ascorbic acid and uric acid. These results indicate that the Cu nanofibril structure prepared via simple oxidation/reduction process can be an excellent candidate to be used as an electrode for glucose sensing application.

Longitudinal Studies of Wearables in Patients with Diabetes: Key Issues and Solutions

Abstract: Glucose monitoring is key to the management of diabetes mellitus to maintain optimal glucose control whilst avoiding hypoglycemia. Non-invasive continuous glucose monitoring techniques have evolved considerably to replace finger prick testing, but still require sensor insertion. Physiological variables, such as heart rate and pulse pressure, change with blood glucose, especially during hypoglycemia, and could be used to predict hypoglycemia. To validate this approach, clinical studies that contemporaneously acquire physiological and continuous glucose variables are required. In this work, we provide insights from a clinical study undertaken to study the relationship between physiological variables obtained from a number of wearables and glucose levels. The clinical study included three screening tests to assess neuropathy and acquired data using wearable devices from 60 participants for four days. We highlight the challenges and provide recommendations to mitigate issues that may impact the validity of data capture to enable a valid interpretation of the outcomes.

Antibacterial and catalytic performance of rGO-CNT-ZrO2 composite

Abstract: In recent years, there has been a rise in public awareness regarding antibacterial properties and commercial opportunities for their use in the medical field. The current study describes the fabrication of a ternary composite, reduced graphene oxide-carbon nanotubes-zirconium oxide (rGO-CNT-ZrO2), and their potential applications for antimicrobial activity and catalytic degradation of neutral red, indigo carmine and eriochrome black-T dyes. In addition, the capability of nanocomposite for UV sensing was examined. These nanocomposites were made using the hydrothermal method. TEM, SEM, FTIR, TGA and XRD were used to characterise and investigate the properties of nanocomposite, and the disc diffusion technique was used to assess their antimicrobial activity. These findings suggest that the developed composite has excellent antimicrobial properties, which could be helpful in the pharmaceutical and medical industries.

Reduced metal nanocatalysts for selective electrochemical hydrogenation of biomass-derived 5-(hydroxymethyl)furfural to 2,5-bis(hydroxymethyl)furan in ambient conditions

Abstract: Selective electrochemical hydrogenation (ECH) of biomass-derived unsaturated organic molecules has enormous potential for sustainable chemical production. However, an efficient catalyst is essential to perform an ECH reaction consisting of superior product selectivity and a higher conversion rate. Here, we examined the ECH performance of reduced metal nanostructures, i.e., reduced Ag (rAg) and reduced copper (rCu) prepared via electrochemical or thermal oxidation and electrochemical reduction process, respectively. Surface morphological analysis suggests the formation of nanocoral and entangled nanowire structure formation for rAg and rCu catalysts. rCu exhibits a slight enhancement in ECH reaction performance in comparison to the pristine Cu. However, the rAg exhibits more than two times higher ECH performance without compromising the selectivity for 5-(HydroxyMethyl) Furfural (HMF) to 2,5-bis(HydroxyMethyl)-Furan (BHMF) formation in comparison to the Ag film. Moreover, a similar ECH current density was recorded at a reduced working potential of 220 mV for rAg. This high performance of rAg is attributed to the formation of new catalytically active sites during the Ag oxidation and reduction processes. This study demonstrates that rAg can potentially be used for the ECH process with minimum energy consumption and a higher production rate.

Futuristic Approach to Cholesterol Detection by Utilizing Non-invasive Techniques

Abstract: Regular blood cholesterol control is an integral part of healthcare for detecting cardiovascular issues immediately. Existing procedures are mostly intrusive and necessitate the collection of blood samples. Furthermore, because of the danger of infection, bruising, and/or haematoma, this measurement method may not be appropriate for continuous or regular examinations. As a result, an alternate option is required, which is known as the noninvasive (NI) approach that does not necessitate the collection of blood samples. Because NI approaches give painless and precise answers, they can be used in place of intrusive procedures. This review article includes a comprehensive investigation on NI methodologies and various NI approaches for detecting cholesterol in the bloodstream. It is important to note that medical system possibilities are changing due to the algorithms for NI techniques, which ultimately project the need for patient monitoring via the internet of medical things (IoMT) and artificial intelligence (AI).

Design and development of a new metamaterial sensor-based Minkowski fractal antenna for medical imaging

Abstract: Abstract The metamaterial sensor antenna is numerically designed to detect breast cancer using breast cancer cell lines, especially relying on the electrical characteristics of breast cancer cells, and designed antenna is measured and the results are observed. The metamaterial sensor antenna is a simple and efficient antenna which is designed using the Minkowski fractal curve with a ring-shaped Split Ring Resonator (SRR). The SRR is chosen because of its inductive and capacitive resonating properties. In addition, the Minkowski fractal curve is used as a defective ground structure to improve sensor sensitivity and selectivity. The numerical investigations are based on different iterations of the Minkowski fractal curve. In that iteration, the third iteration of the Minkowski fractal gives better results. The designed antenna is tested with breast cancer cell lines, and it resonates at a frequency of 2.35, 2.42, and 2.52 GHz for different dielectric constants and conductivity. The simulated design antenna is tested with different cancer cell lines like MDA-MB-231, MCF-7, and HS758-T to ensure its performance and selectivity. The measured result of the fabricated antenna shows that the antenna design resonates at the same frequency as the simulated antenna results.

An efficient transition metal chalcogenide sensor for monitoring respiratory alkalosis

Abstract: For many biomedical applications, high-precision CO2 detection with a rapid response is essential. Due to the superior surface-active characteristics, 2D materials are particularly crucial for electrochemical sensors. The liquid phase exfoliation method of 2D Co2Te3 production is used to achieve the electrochemical sensing of CO2. The Co2Te3 electrode performs better than other CO2 detectors in terms of linearity, low detection limit, and high sensitivity. The outstanding physical characteristics of the electrocatalyst, including its large specific surface area, quick electron transport, and presence of a surface charge, can be credited for its extraordinary electrocatalytic activity. More importantly, the suggested electrochemical sensor has great repeatability, strong stability, and outstanding selectivity. Additionally, the electrochemical sensor based on Co2Te3 could be used to monitor respiratory alkalosis.The online version contains supplementary material available at 10.1007/s13205-023-03497-z.

Novel formulation for co-delivery of cinnamon- and cumin-loaded polymeric nanoparticles to enhance their oral bioavailability

Abstract: Abstract Nanobiotechnology has been an encouraging approach to improving the efficacy of hydrophobic bioactive compounds. The biologically active constituents present in herbal extracts are poorly absorbed, resulting in loss of bioavailability and efficacy. Hence, herbal medicine and nanotechnology are combined to overcome these limitations. The surface-to-volume ratio of nanoparticles is high and as the size is small, the functional properties are enhanced. The present study reports the synthesis of cinnamon and cumin (Ci–Cu) dual drug-loaded poly (D, L-lactide-co-glycolide) (PLGA) nanoparticles (NPs) to overcome the limitations of oral bioavailability and extend the effect of these drugs for alleviating health problems. The solvent evaporation method was adopted for the synthesis, and the as-prepared nanoparticles were characterized by Scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, Transmission electron microscopy (TEM) and X-ray diffraction (XRD). The average size of the formed spherical Ci-Cu nanoparticles ranged between 90 and 120 nm. The encapsulation efficiency of the drug was found to be 79% ± 4.5%. XRD analysis demonstrated that cinnamon and cumin were amorphously scattered in the PLGA matrix. The FTIR bands showed no evident changes suggesting the no direct molecular interactions between the drug and the polymer. At pH 6.9, the release studies in vitro exhibited a burst initially followed by a tendency to obtain a slower steady release. The results indicated that the Cu-Ci dual drug-loaded polymeric NPs has drug release at a slower rate. The time taken for 25% release of drug in Ci-Cu-loaded PLGA NPs was twice as compared to cumin-loaded PLGA Nps, and three times compared to cinnamon-loaded PLGA NPs.