Biosynthesis of copper nanoclusters for fluorescence detection of bilirubin in biofluids.

Copper nanoclusters (Cu NCs) have shown significant attention in sensing of molecular and ionic species. In this work, a single-step biosynthetic approach was introduced for the preparation of fluorescent Cu NCs using Holarrhena pubescens (H. pubescens) leaves extract as a template. The synthesized H. pubescens-Cu NCs act as a nanomolecular probe for the detection of bilirubin in biofluids. The synthesized H. pubescens-Cu NCs displayed highest fluorescence intensity at 454 nm, when excited at 330 nm. Importantly, selective detection of bilirubin was obtained by introducing H. pubescens-Cu NCs as a simple molecular probe. The interaction of bilirubin and H. pubescens-Cu NCs resulted in a remarkable decrease in the emission peak intensity. The developed H. pubescens-Cu NCs-based bilirubin molecular probe has a wide linear range of 0.5-20.00 µM with the limit of detection of 30.54 nM for bilirubin. The promising application of H. pubescens-Cu NCs-based molecular probe was assessed by assaying bilirubin in spiked biofluids.

Uranium standards in drinking water: An examination from scientific and socio-economic standpoints of India.

The detection of uranium in drinking water has ignited concerns among the public, regulators, and policymakers, particularly as around 1% of the 55,554 water samples in India have shown uranium levels surpassing the 60 µg/l guideline established by the Atomic Energy Regulatory Board (AERB) based on radiological toxicity. Further, the Bureau of Indian Standard (BIS), has given a limit of 30 µg/l, which is derived from World Health Organization (WHO) guidelines. Besides the chemical and radiological aspects associated with uranium, factors such as technological constraints in water purification, waste management, environmental factors, and socio-economic conditions significantly influence these guideline values, which are often overlooked. This manuscript explores the variations in approaches for establishing guideline values and highlights the uncertainties arising from dependence on various variables such as intake and usage patterns, inter- and intra-species distinctions, and epidemiological data. A critical analysis indicates that adherence to global guidelines may result in some undesirable environmental issues. By considering factors such as population dynamics, socio-economic conditions, and geological influences, we suggest that limit of 60 µg/l for uranium in drinking water is appropriate for India.

Green Synthetic Approach for the Preparation of Blue Emitting Gold Nanoclusters: A Simple Analytical Method for Detection of Hexaconazole Fungicide.

Blue emissive Argyreia nervosa-capped gold nanoclusters (A. nervosa-AuNCs) were synthesized via a simple environment-friendly method. The developed probe exhibits rapid response towards the target analyte (hexaconazole fungicide). Several characterizations, including FT-IR, UV-visible, fluorescence, HR-TEM, XPS, and fluorescence lifetime, were studied to confirm the formation of A. nervosa-AuNCs. The A. nervosa-AuNCs displayed emission and excitation peaks at 470 and 390 nm, respectively. Furthermore, the quantum yield (QY) of A. nervosa-AuNCs was 21.25%. The as-synthesized A. nervosa-AuNCs showed a good linear response with hexaconazole in the concentration range of 0.025-180 µM, with a detection limit (LOD) of 21.94 nM, indicating A. nervosa-AuNCs could be used as a sensitive and selective probe for detecting hexaconazole through a fluorescence "turn-off" mechanism. The A. nervosa-AuNCs were successfully used to detect hexaconazole in real samples. Moreover, A. nervosa-AuNCs were used as a bio-imaging probe for visualization of Saccharomyces cerevisiae cells.

A numerical model for the prediction of radon flux from uranium mill tailings at Jaduguda, India.

Solid process fine waste or tailings of a uranium mill is a potential source of release of radiologically significant gaseous radon (222Rn). A number of variables such as radium (226Ra) content, porosity, moisture content, and tailings density can affect the extent of emanation from the tailings. Further, if a cover material is used for remediation purposes, additional challenges due to changes in the matrix characteristics in predicting the radon flux can be anticipated. The uranium mill tailings impoundment systems at Jaduguda have been in use for the long-term storage of fine process waste (tailings). A pilot-scale remediation exercise of one of the tailings ponds has been undertaken with 30 cm soil as a cover material. For the prediction of the radon flux, a numerical model has been developed to account for the radon exhalation process at the remediated site. The model can effectively be used to accommodate both the continuous and discrete variable inputs. Depth profiling and physicochemical characterization for the remediated site have been done for the required input variables of the proposed numerical model. The predicted flux worked out is well below the reference level of 0.74 Bq m-2 s-1 IAEA (2004).

Fluorescence 'turn-off-on' assays for neomycin sulphate and K+ ions with orange-red fluorescent molybdenum nanoclusters.

Fluorescent metal nanoclusters (MNCs) have found extensive application in recognizing molecular species. Here, orange-red fluorescent Arg-A. paniculata-MoNCs were synthesized using Andrographis paniculata leaf extract, arginine as a ligand, and MoCl5 as a metal precursor. The Arg-A. paniculata-MoNCs complex exhibited a quantum yield (QY) of 16.91% and excitation/emission wavelengths of 400/665 nm. The synthesized Arg-A. paniculata-MoNCs successfully acted as a probe for assaying neomycin sulphate (NS) via fluorescence turn-off and K+ ions via fluorescence turn-on mechanisms, respectively. Moreover, the developed probe was effectively used to develop a cellulose paper strip-based sensor for detection of NS and K+ ions. Arg-A. paniculata-MoNCs demonstrated great potential for sensing NS and K+ ions, with concentration ranges of 0.1-80 and 0.25-110 µM for NS and K+ ions, respectively. The as-synthesized Arg-A. paniculata-MoNCs efficiently detected NS and K+ ions in food and biofluid samples, respectively.

Green Emissive Molybdenum Nanoclusters for Selective and Sensitive Detection of Hydroxyl Radical in Water Samples.

In this work, Cassia tora (C. tora) have been used as a template to synthesize green fluorescent C. tora molybdenum nanoclusters (C. tora-MoNCs) through a green chemistry approach. These C. tora-MoNCs showed a quantum yield (QY) of 7.72% and exhibited a significant emission peak at 498 nm when excited at 380 nm. The as-prepared C. tora-MoNCs had an average size of 3.48 ± 0.80 nm and showed different surface functionality. The as-synthesized C. tora-MoNCs were successfully identified the hydroxyl radical (•OH) via a fluorescence quenching mechanism. Also, fluorescence lifetime and Stern-Volmer proved that after the addition of •OH radicals it was quenched the fluorescence intensity via a static quenching mechanism. The limit of detection is 9.13 nM, and this approach was successfully utilized for sensing •OH radicals in water samples with a good recovery rate.

Development of Simple Fluorescence Analytical Strategy for the Detection of Triazophos Using Greenish-Yellow Emissive Carbon Dots Derived from Curcuma longa.

This study describes a new method for synthesizing water-soluble carbon dots (CDs) using "Curcuma longa" (green source) named CL-CDs via a single-step hydrothermal process. The as-synthesized CL-CDs exhibited greenish-yellow fluorescence at 548 nm upon excitation at 440 nm. It shows good water stability and exhibits a quantum yield of 19.4%. The developed probe is utilized for sensing triazophos (TZP) pesticide via a dynamic quenching mechanism, exhibiting favorable linearity ranging from 0.5-500 µM with a limit of detection of 0.0042 µM. The as-prepared CL-CDs probe was sensitive and selective towards TZP. Lastly, the successful application of the CL-CDs-based fluorescent probe in water and rice samples highlights its potential as a reliable and efficient method for the detection of TZP in various real sample matrices. Eventually, bioimaging and biocompatibility aspects of CL-CDs have been assessed on Saccharomyces cerevisiae (yeast) cell and lung cancer (A549) cell lines, respectively.

Development of Copper Nanoclusters-Based Turn-Off Nanosensor for Fluorescence Detection of Two Pyrethroid Pesticides (Cypermethrin and Lambda-Cyhalothrin).

Fluorescent copper nanoclusters (Cu NCs) were synthesized by using Withania somnifera (W. somnifera) plant extract as a biotemplate. Aqueous dispersion of W. somnifera-Cu NCs displays intense emission peak at 458 nm upon excitation at 350 nm. This fluorescence emission was utilized for the detection of two pyrethroid pesticides (cypermethrin and lambda-cyhalothrin) via "turn-off" mechanism. Upon the addition of two pyrethiod pesticides independently, the fluorescence emission of W. somnifera-Cu NCs was gradually decreased with increasing concentrations of both pesticides. It was noticed that the decrease in emission intensity at 458 nm was linearly dependent on the logarithm of both pesticides concentrations in the ranges of 0.01-100 µM and of 0.05-100 µM for cypermethrin and lambda-cyhalothrin, respectively. Consequently, the limits of detection were found to be 27.06 and 23.28 nM for cypermethrin and lambda-cyhalothrin, respectively. The as-fabricated W. somnifera-Cu NCs acted as a facile sensor for the analyses of cypermethrin and lambda-cyhalothrin in vegetables (tomato and bottle gourd), which demonstrates that it could be used as portable sensing platform for assaying of two pyrethroid pesticides in food samples.

Synthesis of Greenish-Yellow Fluorescent Copper Nanocluster for the Selective and Sensitive Detection of Fipronil Pesticide in Vegetables and Grain Samples.

In this paper, a new synthetic route is introduced for the synthesis of high-luminescent greenish-yellow fluorescent copper nanoclusters (PVP@A. senna-Cu NCs) using Avaram senna (A. senna) and polyvinylpyrrolidone (PVP) as templates. A. senna plant extract mainly contains variety of phytochemicals including glycosides, sugars, saponins, phenols, and terpenoids that show good pharmacological activities such as anti-inflammatory, antioxidant, and antidiabetic. PVP is a stable and biocompatible polymer that is used as a stabilizing agent for the synthesis of PVP@A. senna-Cu NCs. The size, surface functionality, and element composition of the fabricated Cu NCs were confirmed by various analytical techniques. The as-prepared greenish-yellow fluorescent Cu NCs exhibit significant selectivity towards fipronil, thereby favoring to assay fipronil pesticide with good linearity in the range of 3.0-30 µM with a detection limit of 65.19 nM. More importantly, PVP@A. senna-Cu NCs are successfully applied to assay fipronil in vegetable and grain samples.

Synthesis of copper nanoclusters from Bacopa monnieri leaves for fluorescence sensing of dichlorvos.

In this work, a facile one-step green synthesis was developed for the fabrication of blue fluorescent copper nanocluster (Brahmi-CuNCs) from the extract of Bacopa monnieri (common name is Brahmi) via a microwave method. The as-prepared Brahmi-CuNCs emitted blue fluorescence at 452 nm when excited at 352 nm and showed a quantum yield of 31.32%. Brahmi-derived blue fluorescent CuNCs acted as a probe for fluorescence sensing of dichlorvos. Upon the addition of dichlorvos, the blue emission for Brahmi-CuNCs was gradually turned off, favouring establishment of a calibration graph in the range 0.5-100 µM with a detection limit of 0.23 µM. The as-synthesized Brahmi-CuNCs exhibited marked sensitivity and selectivity towards dichlorvos, favourable for assaying dichlorvos in various samples (cabbage, apple juice, and rice).

Fluorescence "Turn OFF-ON" detection of Fe3+ and propiconazole pesticide using blue emissive carbon dots from lemon peel.

In this study, water-soluble carbon dots (CDs) were employed as a novel fluorescence "turn OFF-ON" sensor to detect Fe3+ ions in pharmaceutical sample and propiconazole (PC) in food samples. Blue fluorescent "LPCDs" are synthesized from the lemon peel that exhibited emission at 468 nm when excited at 378 nm. The average size of the as-prepared LPCDs is 2.03 nm, displaying a quantum yield of 32 %. Fluorescence "turn OFF-ON" strategy was developed for sensing of Fe3+ ion and PC, demonstrating favorable linearity in the range of 0.5-180 µM and 0.1-40 µM with the detection limits of 0.18 µM and 0.054 µM for Fe3+ and PC, respectively. Further, LPCDs-loaded cellulose paper was used as visual reader to detect Fe3+ and PC. This approach was effectively applied to detect Fe3+ and PC in pharmaceutical and vegetable samples.

Dyslipidemia and Thyroid Dysfunction Associated with Psoriasis.

BACKGROUND: Psoriasis is a T-cell mediated inflammatory skin disorder which causes considerable psychosocial disability resulting in major impact on patient's quality of life. The dominant response of Th1 cells and the high expression of related inflammatory factors appears in both psoriasis and thyroid dysfunction. Psoriasis can lead to increased risk of incidence of cardiovascular events for which dyslipidemia is an important risk factor. This study aims to evaluate thyroid function and lipid profile and its association in patients with psoriasis. METHODS: This was a prospective case-control study conducted at the Department of Biochemistry, Nobel Medical College Teaching Hospital from November 2021 to October 2022. Seventy six clinically diagnosed psoriatic patients were taken as case and eighty non-psoriatic patients coming for other skin lesions were included in the study as control. Thyroid function test (serum free T3, T4, TSH) and lipid profile (total cholesterol, low density lipoprotein, high density lipoprotein and triglyceride) were done. RESULTS: Hypothyroidism was most common thyroid abnormalities in our study population which was 13.15% (n=10). The lipid profile parameters were significantly higher in the psoriatic patients than in the controls (p<0.001). The odds of psoriatic patient having thyroid dysfunction was 2.8 times higher compared to other non-psoriatic patients and the odds of psoriatic patient having dyslipidemia was 8.7 times higher compared to other non-psoriatic patients. CONCLUSIONS: It is thus useful to assess thyroid function test and lipid profile in patients with psoriasis considering their role in etiopathogenesis and co-morbidity of psoriasis.

UHPLC-MS/MS and QRT-PCR profiling of PGP agents and Rhizobium spp. of induced phytohormones for growth promotion in mungbean (var. Co4).

In present study, five potential strains with different plant growth promotion (PGP) characteristics were used. By considering various PGP properties of different bacterial strains, several treatments based on various combinations were developed and studied on mungbean (var. Co4). The quantification of the phytohormones was performed on ultrahigh-performance liquid chromatograph coupled to heated electrospray ionization tandem mass spectrometry (UHPLC/HESI-MS/MS). Indole 3-acetic acid (IAA) and Indole 3-butyric acid (IBA) were quantified in positive ionization mode while Gibberellic acid (GA3) and salicylic acid (SA) were quantified in negative ionization mode. Among all the treatments two penta combinations of consortia 1 (Rhizobium + Azospirillum + Pseudomonas + Bacillus spp. + Bacillus licheniformis) and consortia 2 (Rhizobium + Azotobacter + Pseudomonas + Bacillus spp. + Bacillus licheniformis) were found most effective. Higher amount of IAA (1.043 µg g-1), IBA (0.036 µg g-1), GA3 (1.999 µg g-1) and SA (0.098 µg g-1) Fresh weight (FW) were found in treated adolescent root tissues of consortia 2 as compared to consortia 1. Moreover, transcriptional level of the plant hormones were 2-4 fold higher in the relative gene expression study of three genes: ARF (Auxin responsive factors), ERF-IF (Ethylene-responsive Initiation Factors) and GAI (Gibberellic-Acid Insensitive) in consortia 2, on the 15th, 30th and 45th day using quantitative real time-Polymerase chain reaction (qRT-PCR). Furthermore, Yield attributing characters like, the number of nodules plant-1, number of pods plant-1, weight of nodule and seed yield plant-1 were also increased as compared to the control. As a result, the current research elucidated that penta combinations consortium of Rhizobium sp. and rhizobacteria can be developed as a single delivery system biofertilizer for enhancing mungbean productivity.

DIMY: Enabling privacy-preserving contact tracing.

The infection rate of COVID-19 and the rapid mutation ability of the virus has forced governments and health authorities to adopt lockdowns, increased testing, and contact tracing to reduce the virus's spread. Digital contact tracing has become a supplement to the traditional manual contact tracing process. However, although several digital contact tracing apps are proposed and deployed, these have not been widely adopted due to apprehensions surrounding privacy and security. In this paper, we present a blockchain-based privacy-preserving contact tracing protocol,"Did I Meet You" (DIMY). The protocol provides full-lifecycle data privacy protection on the devices as well as the back-end servers to address most of the privacy concerns associated with existing protocols. We have employed Bloom filters to provide efficient privacy-preserving storage and have used the Diffie-Hellman key exchange for secret sharing among the participants. We show that DIMY provides resilience against many well-known attacks while introducing negligible overheads. DIMY's footprint on the storage space of clients' devices and back-end servers is also significantly lower than other similar state-of-the-art apps.

Simple hydrothermal approach for synthesis of fluorescent molybdenum disulfide quantum dots: Sensing of Cr3+ ion and cellular imaging.

Nowadays, fluorescent molybdenum disulfide quantum dots (MoS2 QDs) have proven to be potential candidates in the sensing and bioimaging areas owing to their exceptional intrinsic characteristics. Here, a simple hydrothermal strategy was explored for the preparation of MoS2 QDs using ammonium heptamolybdate and 6-mercaptopurine (6-MP) as precursors. The emission peak of MoS2 QDs was significantly quenched in the presence Cr3+ ion due to the selective surface chemistry on the surfaces of MoS2 QDs. The designed fluorescent MoS2 QDs showed a linear fluorescence quenching response with increasing concentration of Cr3+ ion (0.1-10 µM), allowing to detect Cr3+ ion even at 0.08 µM. This fluorescent MoS2 QDs were utilized for the quantification of Cr3+ ion in real samples (water and biological samples). Interestingly, the synthesized MoS2 QDs exhibited negligible cytotoxicity on NRK cells and acted as good candidates for imaging of Trichoderma viride fungal cells.

Acid Oxidation of Muskmelon Fruit for the Fabrication of Carbon Dots with Specific Emission Colors for Recognition of Hg2+ Ions and Cell Imaging.

In this study, water-soluble emissive carbon dots (CDs) are effectively fabricated with specific optical properties and colors by acid oxidation of muskmelon (Cucumis melo) fruit, which are termed as C. melo CDs (CMCDs). The fluorescence properties of CMCDs were tuned by controlling the experimental conditions that allow them to emit different colors, that is, blue (B-), green (G-), and yellow (Y-) CMCDs, with different emission wavelengths at 432, 515, and 554 nm when excited at 342, 415, and 425 nm, respectively. The fabricated multicolor-emissive CDs were confirmed by various analytical techniques. The sizes of B-, G-, and Y-CMCDs were found to be ∼3.5, ∼4.3, and ∼5.8 nm, respectively. The as-prepared CMCDs display stable emissions with quantum yields of 7.07, 26.9, and 14.3% for the three CMCDs, which could act as a promising probe for the selective detection of Hg2+ ions. Upon the addition of Hg2+ ions, the fluorescence intensity of G-CMCDs at 515 nm was quenched largely than that of B- and Y-CMCDs. The spectroscopic results display that the G-CMCDs acted as a sensor for the detection of Hg2+ ions with a wide linear range from 1.0 to 25 µM (R 2 = 0.9855) with a detection limit of 0.33 µM. This method was successfully applied to detect Hg2+ ions in biological and water samples. The fabricated multicolor-emissive CMCDs possess the cell (Cunninghamella elegans, Aspergillus flavus, and Rhizoctonia solani) imaging property, suggesting the biocompatible nature for multicolor imaging of various cells.

Green synthesis of multi-color emissive carbon dots from Manilkara zapota fruits for bioimaging of bacterial and fungal cells.

Natural resources have widely been used as precursors for the preparation of ultra-small carbon dots (C-dots) due to ease of availability, low cost and C-dots with high quantum yields (QYs). Herein, water dispersible multi-color emissive C-dots were obtained from Manilkara zapota fruits. The emission of C-dots was well tuned by sulphuric acid and phosphoric acids, which results to generate blue-, green- and yellow- C-dots. The fabricated C-dots exhibit blue, green and yellow color emissions when irradiated them under UV light at 365 nm. The emission/excitation peaks of blue-, green-, and yellow- C-dots were observed at 443, 515 and 563 nm when excited at 350, 420 and 440 nm, respectively. The QYs of blue-, green-, and yellow- C-dots are 5.7, 7.9 and 5.2%. The average sizes of blue- green- and yellow- C-dots are 1.9 ±â€¯0.3, 2.9 ±â€¯0.7and 4.5 ±â€¯1.25 nm, respectively. Because of ultra-small size and biocompatibility, three C-dots act as promising bioimaging agents for imaging of cells (E. coli, Aspergillus aculeatus and Fomitopsis sp). The cytotoxicity on HeLa cells indicates that three C-dots have non-toxic nature, which confirms their biocompatibility. The ultra-small C-dots were effectively distributed in the cytoplasm of the cells, ensuring the potential applications in cell imaging and biomedical studies.

Influence of doping ion, capping agent and pH on the fluorescence properties of zinc sulfide quantum dots: Sensing of Cu2+ and Hg2+ ions and their biocompatibility with cancer and fungal cells.

Herein, a facile one-pot synthetic method was explored for the fabrication of glutathione capped Mn2+ doped­zinc sulphide quantum dots (GSH-Mn2+-ZnS QDs) for both fluorescent detection of Cu2+ and Hg2+ ions and for fluorescence imaging of two cancer (RIN5F and MDAMB231) and fungal (Rhizopus oryzae) cells. Particularly, doping of Mn2+ into ZnS QDs nanocrystal structure resulted a great improvement in the fluorescence properties of ZnS QDs. The emission peak of undoped ZnS QDs was found at 447 nm, which is due to the large number of surface defects in the ZnS QDs nanostructures. Under identical conditions, there is a good linear relationship between the quenching of fluorescence intensity and analytes (Cu2+ and Hg2+ ions) concentration in the range of 0.005 to 0.2 mM and of 0.025 to 0.4 mM for Cu2+ and Hg2+ ions, respectively. The GSH-Mn2+-ZnS QDs exhibit least cytotoxicity against RIN5F and MDAMB231 cells, demonstrating the multifunctional applications in sensing of metal ions and biocompatibility towards cancer (RIN5F and MDAMB231) and fungal (Rhizopus oryzae) cells.

Novel carbonized bone meal for defluoridation of groundwater: Batch and column study.

Low cost naturally available bone meal was carbonized and its fluoride adsorption capacity was explored. Carbonized bone meal (CBM) produced at 550°C, 4 h carbonization time and a heating rate of 60°C/min, showed fluoride adsorption capacity of 14 mg g-1. Adsorbent was characterized using scanning electron microscopy, X-ray diffraction, X-ray fluoroscence, thermogravimetric analysis and Fourier transform infrared spectroscopy to highlight its physical and chemical properties. Best fluoride uptake capacity was observed for 0.2 mm particle size, 7 g L-1 adsorbent concentration and at pH 6.5. Fluoride uptake was endothermic and chemisorption in nature. Effective diffusivity and mass transfer coefficient were obtained as 6 × 10-11 m2 s-1 and 9 × 10-5 m s-1 from shrinking core model. Sulphate and carbonate showed the highest interference effect on adsorption of fluoride by CBM. Maximum desorption was observed at basic pH (pH 12). Fixed bed study was performed and effect of different parameters (bed height, inlet flow rate and initial concentration) was investigated. Efficiency of the adsorbent using real life fluoride contaminated groundwater solution was also observed.

Tuning of gold nanoclusters sensing applications with bovine serum albumin and bromelain for detection of Hg2+ ion and lambda-cyhalothrin via fluorescence turn-off and on mechanisms.

Herein, fluorescent gold nanoclusters (Au NCs) were obtained by one-pot synthetic method using bovine serum albumin (BSA) and bromelain as templates. As-synthesized fluorescent Au NCs were stable and showed bright red fluorescence under UV lamp at 365 nm. The fluorescent Au NCs exhibit the emission intensity at 648 nm when excited at 498 nm. Various techniques were used such as spectroscopy (UV-visible, fluorescence, and Fourier-transform infrared), high-resolution transmission electron microscopy, and dynamic light scattering for the characterization of fluorescent Au NCs. The values of I0/I at 648 nm are proportional to the concentrations of Hg2+ ion in the range from 0.00075 to 5.0 µM and of lambda-cyhalothrin in the range from 0.01 to 10 µM with detection limits of 0.0003 and 0.0075 µM for Hg2+ ion and lambda-cyhalothrin, respectively. The practical application of the probe was successfully demonstrated by analyzing Hg2+ ion and lambda-cyhalothrin in water samples. In addition, Au NCs used as probes for imaging of Simplicillium fungal cells. These results indicated that the as-synthesized Au NCs have proven to be promising fluorescent material for the sensing of Hg2+ ion and lambda-cyhalothrin in environmental and for imaging of microorganism cells in biomedical applications.