Ionic liquid tuned titanium dioxide nanostructures as an efficient colorimetric sensing platform for dopamine detection

Dopamine is a neurotransmitter distributed in the central and peripheral nervous system, its lower or higher production results in various pathological disorders. Various nanoparticles systems have been used in the sensing of dopamine while in the present work ionic liquid tuned titanium dioxide nanoparticles (TiO2 NPs) was first time evaluated in colorimetric detection of dopamine. TiO2 NPs have been synthesized by hydrothermal process and analyzed by different characterization techniques such as FTIR, XRD, and SEM that confirmed the desired synthesis. 1-H-3-methylimidazolium acetate (ionic liquid-a known conducting species) was prepared by the neutralization method. Colorimetric change in color from pinkish grey to reddish-brown with an increase in dopamine concentration was analyzed using a UV–Vis spectrophotometer. To optimize the protocol various parameters like nanoparticles loading, conc. of dopamine etc were optimized. The quantification and limit of detection for the proposed sensor were calculated as 2.55 × 10−7 M and 7.67 × 10−8 M respectively, and 1 × 10−8–3.6 × 10−6 M linear range with an R2 value of 0.9998. At an optimum temperature of 25 °C and at pH 12 the proposed sensor response time was just 4 min for dopamine detection. The proposed sensor has been also used for the dopamine detection in physiological solution. The proposed sensor showed good sensitivity and selectivity for dopamine sensing

Colorimetric based sensing of dopamine using ionic liquid functionalized drug mediated silver nanostructures

© 2020 Elsevier B.V. The present work reports the drug mediated synthesis of silver nanoparticles (AgNPs) for sensing of dopamine (biomarker Parkinson\u27s disease and others). Augmentin drug was chosen because of functionalities and aromaticity in its structure which will not only work in the synthesis of AgNPs but also enhance the electron density on nanoparticles (NPs) for better sensing properties. 1-H-3-methylimidazolium acetate ionic liquid (IL) having characteristic properties of aromaticity and conductivity were coated on to the surface of NPs to further enhance the mentioned properties. The FTIR, Raman spectroscopy and XRD analysis demonstrate the characteristic peaks assigned to AgNPs. SEM analysis shows round shaped morphology and EDX showed strong band for AgNPs. TGA analysis showed maximum degradation at 340 °C for the prepared AgNPs. The functionalized AgNPs/IL was used in sensing of dopamine. Different reaction conditions have been optimized to find the optimal performance of AgNPs/IL such as; (a) pH (b) amount of Ag/IL (c) time of incubation; (d) temperature. The response time of the proposed sensor for dopamine detection was only 4 min with a visible colorimetric change from light grey to brown color. The proposed sensor showed a wide linear range (1 × 10−8–3.6 × 10−6 M), low limit of detection 1.18 × 10−7 M, and limit of quantification 3.92 × 10−7 M with an R2 value of 0.9997. The IL capped Ag nano assembly exhibited no reactivity towards folic acid, urea, ascorbic acid, Ca+2, K+ and was successfully used to quantify dopamine in physiological sample

Fabrication of a colorimetric sensor using acetic acid-capped drug-mediated copper oxide nanoparticles for nitrite biosensing in processed food

Nitrite (NO2 −) and nitrate (NO3 −) are frequently used in cured meat products as preservatives, as they give a better taste and work well in color fixation. As a key possible carcinogen, excessive dietary consumption of NO2 − in cured meat products would be bad for health. Herein, copper oxide nanoparticles (CuO NPs) were synthesized using the drug Augmentin as a reducing and capping agent. The desired synthesis of CuO NPs was confirmed by various characterization techniques, including UV–visible spectroscopy, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, thermal gravimetric analysis, X-ray diffraction, and scanning electron microscopy. The new approach of drug-mediated acetic acid-capped CuO NPs was developed for simple colorimetric detection of nitrite ions in a mimic solution of processed food. The color of the detection system changes from brown to yellow with the increase in the concentration of NO2 − and has been observed with the naked eye. The selectivity of the NO2 − detection system by the UV–visible spectrum and the naked eye is compared to other ions, such as Br−, I−, Cl−1, PO4 −3, CO3 2−, and SO4 2−. The platform was successfully employed for the determination of nitrite in real samples. Moreover, this probe can be used for the sensitive detection of NO2 − with a linear range of 1 × 10−8 to 2.40 × 10−6 M, a detection limit of 2.69 × 10−7 M, a limit of quantification 8.9 × 10−7 M, and a regression coefficient (R 2) of 0.997. Our results suggest that this sensor can be used for on-site analysis and quantification as well as in the fields of disease diagnosis, environmental monitoring, and food safety

Proteome level analysis of drug-resistant Prevotella melaninogenica for the identification of novel therapeutic candidates

The management of infectious diseases has become more critical due to the development of novel pathogenic strains with enhanced resistance. Prevotella melaninogenica, a gram-negative bacterium, was found to be involved in various infections of the respiratory tract, aerodigestive tract, and gastrointestinal tract. The need to explore novel drug and vaccine targets against this pathogen was triggered by the emergence of antimicrobial resistance against reported antibiotics to combat P. melaninogenica infections. The study involves core genes acquired from 14 complete P. melaninogenica strain genome sequences, where promiscuous drug and vaccine candidates were explored by state-of-the-art subtractive proteomics and reverse vaccinology approaches. A stringent bioinformatics analysis enlisted 18 targets as novel, essential, and non-homologous to humans and having druggability potential. Moreover, the extracellular and outer membrane proteins were subjected to antigenicity, allergenicity, and physicochemical analysis for the identification of the candidate proteins to design multi-epitope vaccines. Two candidate proteins (ADK95685.1 and ADK97014.1) were selected as the best target for the designing of a vaccine construct. Lead B- and T-cell overlapped epitopes were joined to generate potential chimeric vaccine constructs in combination with adjuvants and linkers. Finally, a prioritized vaccine construct was found to have stable interactions with the human immune cell receptors as confirmed by molecular docking and MD simulation studies. The vaccine construct was found to have cloning and expression ability in the bacterial cloning system. Immune simulation ensured the elicitation of significant immune responses against the designed vaccine. In conclusion, our study reported novel drug and vaccine targets and designed a multi-epitope vaccine against the P. melaninogenica infection. Further experimental validation will help open new avenues in the treatment of this multi-drug-resistant pathogen

Computer-aided identification of Mycobacterium tuberculosis resuscitation-promoting factor B (RpfB) inhibitors from Gymnema sylvestre natural products

Tuberculosis (TB), an infectious disease caused by multi-drug resistant Mycobacterium tuberculosis (Mtb), has been a global health concern. Mtb affects over a third of the world’s population, causing two million deaths annually due to its dormancy and propensity to spread infection during this period. Resuscitation-promoting factor B (RpfB) plays a pivotal role in the growth of Mtb during dormant periods, making it a critical target for eliminating Mtb and curing TB. Gymnema sylvestre is a famous medicinal plant with several medicinal properties, including antimicrobial activity; however, the therapeutic potential of the various reported metabolites of this plant against Mtb has not yet been explored. The aim of this study was to explore the reported natural products of G. sylvestre against the RpfB of the Mtb. A total of 131 reported secondary metabolites of this plant were collected and virtually screened against the RpfB. We particularly targeted the Glu292 residue of RpfB as it is crucial for the catalysis of this protein. From our in-house library, 114 compounds showed a binding affinity higher than the standard drug. The binding stability of the top three lead compounds was further confirmed through MD simulation analysis. Drug likeness analyses indicated that the ten hits had zero violations of the Lipinski rule of five. In addition, analyses of pharmacokinetics, toxicity, and target prediction revealed that the top compounds are devoid of toxicity and do not affect human proteins. Additionally, they reflect multifaceted approach as anti-TB agents. Our selected hits not only exhibit molecular properties favoring physiological compatibility but also exhibit properties enhancing their potential efficacy as therapeutic candidates. The compounds investigated here are worthy of experimental validation for the discovery of novel treatments against TB. Further, this study also provides a promising avenue for research on the pharmacological potential of G. sylvestre

Colorimetric sensing of uric acid based on sawdust-deposited silver nanoparticles via an eco-friendly and cost-effective approach

Uric acid is directly linked to gout, arthritis, neurological, cardiovascular, and kidney-related disorders. It is a byproduct obtained from the breakdown of purines and a significant indicator of hyperuricemia observed in both urine and blood. In the absence of any enzyme, it's quite difficult to develop a novel, cost-effective, and clinical method for uric acid detection. Herein, we report a very simple, low-cost, and non-enzymatic method for the selective identification and quantification of uric acid using green synthesized silver nanoparticles (Ag NPs). The desired Ag NPs were synthesized by the hydrothermal method using Erythrina suberosa sawdust as a deagglomeration agent and Psidium guajava extract as a reductant. The synthesis of the sensing platform, i.e., sawdust-deposited Ag NPs, was confirmed through different techniques such as UV-Vis spectrophotometer, FTIR, XRD, EDX, and scanning electron microscopy (SEM). Sawdust can offer a good, environmentally friendly, and cost-effective strategy to overcome the problem of agglomeration in nanoparticles. The enzyme mimic, with the help of H2O2, oxidizes the colorless 3,3′,5,5′-tetramethylbenzidine (TMB) to oxidized TMB with a blue-green color. The addition of uric acid reduces the oxidized TMB to a colorless product, resulting in a colorimetric change. For quality improvement, different reaction parameters, including pH, time, TMB, and NPs concentration, were optimized. Our proposed sensor responds in linear ranges of 0.04–0.360 μM, with a limit of quantification of 0.01 μM and a limit of detection of 0.004 μM. The suggested enzyme mimic detected uric acid in blood samples, with particular specificity in the presence of competitive analytes

New Transcription Factors Involved With Postnatal Ventral Prostate Gland Development In Male Wistar Rats During The First Week

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Aims: The high incidence in men of prostatic diseases, including benign and malignant tumors, makes the understanding of prostate development and biology very important. Understanding the organogenesis of the prostate gland has been a substantial challenge as "prostatic code" is not well defined at the present time. The novelty of this work lies in unveiling new transcription factors (TFs) during neonatal ventral prostate (VP) gland development in male Wistar rats. Main methods: The techniques of qRT-PCR and immunohistochemistry have been employed to perform this work while the VP gland was obtained from neonatal rats at day zero (the day of birth) day 3 and 6. Key findings: 16 TFs were studied and we found an increased expression of Eya2, Lhrh and Znf142, invariable levels of Znf703 and Dbp, and decreased expression of 11 others at postnatal development day 3 and 6 as compared to day zero. ZNF703 was found by immunohistochemistry in epithelial cells at days 0,3 and 6. qRT-PCR for Eya2 and Dmrt2 showed the highest and lowest fold change for them respectively, and immunohistochemistly showed that the former is being expressed at the three selected time points while the latter appears to be diminishing with very few cells expressing it until day 6. Significance: Results from this work is reporting the role of these TFs for the first time and will significantly contribute to the current understanding of the development and branching morphogenesis of the neonatal VP gland during the first week of postnatal development. (C) 2015 Elsevier Inc All rights reserved.143168173World Academy of Sciences (TWAS)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Microwave-Induced Modification of Physical and Functional Characteristics and Antioxidant Potential of Alkali-Soluble Cell Wall Polysaccharides of Nelumbo nucifera Rhizome

The alkali-soluble cell wall polysaccharides (CWPs), extracted from Nelumbo nucifera rhizome flour (NNRF), were treated with microwave radiation to modify their physical characteristics, functional properties, and antioxidant potential. The NNRF was treated at different levels of microwave treatment time (1, 2, 3, 4 and 5 min) using the low-medium intensity (200 W). The cell wall was isolated and CWPs were extracted in 10% KOH solution followed by their physical, functional, and antioxidant characterization. Microwave treatment resulted in the morphological, structural and compositional modifications in CWPs that were directly correlated with their functional properties and antioxidant potential. A significant (p \u3c 0.05) time-dependent exponential decrease in extract yield, exponential increase in water holding, oil holding, and swelling capacities, a polynomial increase in iron-binding capacity, and a linear increase in antioxidant properties including Trolox equivalent total antioxidant activity, ferrous reducing power, and free radical scavenging capacity of microwave-treated CWPs was observed. The increase in the studied functional and antioxidant potential of the treated samples may be due microwave-induced exposure of hydroxyl groups and uronic acid residues in CWPs. The data would be a valuable contribution to the literature regarding microwave-induced modification in physical, functional and antioxidant properties of CWPs of N. nucifera rhizome

Supramolecular solvent-based liquid phase extraction of antimony prior to spectrophotometric quantification

Antimony (Sb) is highly hazardous to human health even in minute concentration. Therefore, its accurate and precise determination in the real environmental samples is of immense importance. In this work for the first time, UV-Vis spectrophotometric method was developed for the quantification of Sb(III) from water samples using supramolecular solvent (undecanol-tetrahydrofuran)-based extraction. The maximum absorption wavelength for antomony-diathizone complex was found to be 590 nm having molar absorptivity of 3.1 x 10(4) L.mol.cm(-1). Factors affecting extraction efficiency like solution sample volume, amount of chelating agent, pH, matrix effect, and type and volume of supramolecular solvent were determined and optimized. Analytical parameters like limit of detection (0.19 mu g L-1), limit of quantification (0.62 mu g L-1), pre-concentration factor (15), enhancement factor (15), and relative standard deviation for 8 successive analysis (0.8%) were calculated under optimized experimental conditions. The method was applied to real water samples like tap water of laboratory, waste water from Kohat hospitals, and dam water (Tanda dam Kohat) with quantitative addition recovery (94-100%)