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1.
Small ; 20(32): e2400679, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38488771

RESUMEN

Chalcogel represents a unique class of meso- to macroporous nanomaterials that offer applications in energy and environmental pursuits. Here, the synthesis of an ion-exchangeable amorphous chalcogel using a nominal composition of K2CoMo2S10 (KCMS) at room temperature is reported. Synchrotron X-ray pair distribution function (PDF), X-ray absorption near-edge structure (XANES), and extended X-ray absorption fine structure (EXAFS) reveal a plausible local structure of KCMS gel consisting of Mo5+ 2 and Mo4+ 3 clusters in the vicinity of di/polysulfides which are covalently linked by Co2+ ions. The ionically bound K+ ions remain in the percolating pores of the Co-Mo-S covalent network. XANES of Co K-edge shows multiple electronic transitions, including quadrupole (1s→3d), shakedown (1s→4p + MLCT), and dipole allowed 1s→4p transitions. Remarkably, despite a lack of regular channels as in some crystalline solids, the amorphous KCMS gel shows ion-exchange properties with UO2 2+ ions. Additionally, it also presents surface sorption via [S∙∙∙∙UO2 2+] covalent interactions. Overall, this study underscores the synthesis of quaternary chalcogels incorporating alkali metals and their potential to advance separation science for cations and oxo-cationic species by integrating a synergy of surface sorption and ion-exchange.

2.
Crit Rev Biotechnol ; : 1-20, 2024 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-38710611

RESUMEN

Every year, a huge amount of lethal compounds, such as synthetic dyes, pesticides, pharmaceuticals, hydrocarbons, etc. are mass produced worldwide, which negatively affect soil, air, and water quality. At present, pesticides are used very frequently to meet the requirements of modernized agriculture. The Food and Agriculture Organization of the United Nations (FAO) estimates that food production will increase by 80% by 2050 to keep up with the growing population, consequently pesticides will continue to play a role in agriculture. However, improper handling of these highly persistent chemicals leads to pollution of the environment and accumulation in food chain. These effects necessitate the development of technologies to eliminate or degrade these pollutants. Degradation of these compounds by physical and chemical processes is expensive and usually results in secondary compounds with higher toxicity. The biological strategies proposed for the degradation of these compounds are both cost-effective and eco-friendly. Microbes play an imperative role in the degradation of xenobiotic compounds that have toxic effects on the environment. This review on the fate of xenobiotic compounds in the environment presents cutting-edge insights and novel contributions in different fields. Microbial community dynamics in water bodies, genetic modification for enhanced pesticide degradation and the use of fungi for pharmaceutical removal, white-rot fungi's versatile ligninolytic enzymes and biodegradation potential are highlighted. Here we emphasize the factors influencing bioremediation, such as microbial interactions and carbon catabolism repression, along with a nuanced view of challenges and limitations. Overall, this review provides a comprehensive perspective on the bioremediation strategies.

3.
Acc Chem Res ; 49(12): 2725-2735, 2016 12 20.
Artículo en Inglés | MEDLINE | ID: mdl-27993003

RESUMEN

Surface-enhanced Raman spectroscopy (SERS) fingerprinting is highly promising for identifying disease markers from complex mixtures of clinical sample, which has the capability to take medical diagnoses to the next level. Although vibrational frequency in Raman spectra is unique for each biomolecule, which can be used as fingerprint identification, it has not been considered to be used routinely for biosensing due to the fact that the Raman signal is very weak. Contemporary SERS has been demonstrated to be an excellent analytical tool for practical label-free sensing applications due its ability to enhance Raman signals by factors of up to 108-1014 orders of magnitude. Although SERS was discovered more than 40 years ago, its applications are still rare outside the spectroscopy community and it is mainly due to the fact that how to control, manipulate and amplify light on the "hot spots" near the metal surface is in the infancy stage. In this Account, we describe our contribution to develop nanoachitecture based highly reproducible and ultrasensitive detection capability SERS platform via low-cost synthetic routes. Using one-dimensional (1D) carbon nanotube (CNT), two-dimensional (2D) graphene oxide (GO), and zero-dimensional (0D) plasmonic nanoparticle, 0D to 3D SERS substrates have been designed, which represent highly powerful platform for biological diagnosis. We discuss the major design criteria we have used to develop robust SERS substrate to possess high density "hot spots" with very good reproducibility. SERS enhancement factor for 3D SERS substrate is about 5 orders of magnitude higher than only plasmonic nanoparticle and more than 9 orders of magnitude higher than 2D GO. Theoretical finite-difference time-domain (FDTD) stimulation data show that the electric field enhancement |E|2 can be more than 2 orders of magnitude in "hot spots", which suggests that SERS enhancement factors can be greater than 104 due to the formation of high density "hot spots" in 3D substrate. Next, we discuss the utilization of nanoachitecture based SERS substrate for ultrasensitive and selective diagnosis of infectious disease organisms such as drug resistance bacteria and mosquito-borne flavi-viruses that cause significant health problems worldwide. SERS based "whole-organism fingerprints" has been used to identify infectious disease organisms even when they are so closely related that they are difficult to distinguish. The detection capability can be as low as 10 CFU/mL for methicillin-resistant Staphylococcus aureus (MRSA) and 10 PFU/mL for Dengue virus (DENV) and West Nile virus (WNV). After that, we introduce exciting research findings by our group on the applications of nanoachitecture based SERS substrate for the capture and fingerprint detection of rotavirus from water and Alzheimer's disease biomarkers from whole blood sample. The SERS detection limit for ß-amyloid (Aß proteins) and tau protein using 3D SERS platform is several orders of magnitude higher than the currently used technology in clinics. Finally, we highlight the promises, major challenges and prospect of nanoachitecture based SERS in biomedical diagnosis field.


Asunto(s)
Biomarcadores/análisis , Nanoestructuras/química , Espectrometría Raman/métodos , Péptidos beta-Amiloides/sangre , Sustancias Explosivas/análisis , Oro/química , Grafito/química , Humanos , Técnicas Inmunológicas/métodos , Límite de Detección , Nanopartículas del Metal/química , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Nanotubos de Carbono/química , Óxidos/química , Virus ARN/inmunología , Virus ARN/aislamiento & purificación , Reproducibilidad de los Resultados , Proteínas tau/sangre
4.
Artículo en Inglés | MEDLINE | ID: mdl-28095116

RESUMEN

This review summarizes recent advances on design strategies for shape-controlled anisotropic gold nanoparticles. Detailed chemical mechanism has been discussed to understand the anisotropic growth. The effect of various chemical parameters and surface facets for the formation of different shaped anisotropic nanoparticles have been addressed.


Asunto(s)
Oro/química , Nanopartículas del Metal/química , Nanotecnología/métodos , Anisotropía
5.
Int J Med Microbiol ; 305(2): 238-42, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25620353

RESUMEN

The paper provides a short overview of three investigated bacterial protein toxins, colicin M (Cma) of Escherichia coli, pesticin (Pst) of Yersinia pestis and hemolysin (ShlAB) of Serratia marcescens. Cma and Pst are exceptional among colicins in that they kill bacteria by degrading the murein (peptidoglycan). Both are released into the medium and bind to specific receptor proteins in the outer membrane of sensitive E. coli cells. Subsequently they are translocated into the periplasm by an energy-consuming process using the proton motive force. For transmembrane translocation the colicins unfold and refold in the periplasm. In the case of Cma the FkpA peptidyl prolyl cis-trans isomerase/chaperone is required. ShlA is secreted and activated through ShlB in the outer membrane by a type Vb secretion mechanism.


Asunto(s)
Proteínas Bacterianas/metabolismo , Toxinas Bacterianas/metabolismo , Bacteriocinas/metabolismo , Colicinas/metabolismo , Proteínas Hemolisinas/metabolismo , Escherichia coli/metabolismo , Transporte de Proteínas , Serratia marcescens/metabolismo , Yersinia pestis/metabolismo
6.
Bioconjug Chem ; 26(2): 235-42, 2015 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-25565372

RESUMEN

Tumor metastasis is responsible for 1 in 4 deaths in the United States. Though it has been well-documented over past two decades that circulating tumor cells (CTCs) in blood can be used as a biomarker for metastatic cancer, there are enormous challenges in capturing and identifying CTCs with sufficient sensitivity and specificity. Because of the heterogeneous expression of CTC markers, it is now well understood that a single CTC marker is insufficient to capture all CTCs from the blood. Driven by the clear need, this study reports for the first time highly efficient capture and accurate identification of multiple types of CTCs from infected blood using aptamer-modified porous graphene oxide membranes. The results demonstrate that dye-modified S6, A9, and YJ-1 aptamers attached to 20-40 µm porous garphene oxide membranes are capable of capturing multiple types of tumor cells (SKBR3 breast cancer cells, LNCaP prostate cancer cells, and SW-948 colon cancer cells) selectively and simultaneously from infected blood. Our result shows that the capture efficiency of graphene oxide membranes is ~95% for multiple types of tumor cells; for each tumor concentration, 10 cells are present per milliliter of blood sample. The selectivity of our assay for capturing targeted tumor cells has been demonstrated using membranes without an antibody. Blood infected with different cells also has been used to demonstrate the targeted tumor cell capturing ability of aptamer-conjugated membranes. Our data also demonstrate that accurate analysis of multiple types of captured CTCs can be performed using multicolor fluorescence imaging. Aptamer-conjugated membranes reported here have good potential for the early diagnosis of diseases that are currently being detected by means of cell capture technologies.


Asunto(s)
Aptámeros de Nucleótidos , Separación Celular/métodos , Grafito/química , Células Neoplásicas Circulantes/patología , Óxidos/química , Aptámeros de Nucleótidos/química , Biomarcadores de Tumor , Línea Celular Tumoral , Colorantes/química , Humanos , Membranas Artificiales , Porosidad
7.
Chem Soc Rev ; 43(17): 6370-404, 2014 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-24902784

RESUMEN

In the last few decades, Förster resonance energy transfer (FRET) based spectroscopy rulers have served as a key tool for the understanding of chemical and biochemical processes, even at the single molecule level. Since the FRET process originates from dipole-dipole interactions, the length scale of a FRET ruler is limited to a maximum of 10 nm. Recently, scientists have reported a nanomaterial based long-range optical ruler, where one can overcome the FRET optical ruler distance dependence limit, and which can be very useful for monitoring biological processes that occur across a greater distance than the 10 nm scale. Advancement of nanoscopic long range optical rulers in the last ten years indicate that, in addition to their long-range capability, their brightness, long lifetime, lack of blinking, and chemical stability make nanoparticle based rulers a good choice for long range optical probes. The current review discusses the basic concepts and unique light-focusing properties of plasmonic nanoparticles which are useful in the development of long range one dimensional to three dimensional optical rulers. In addition, to provide the readers with an overview of the exciting opportunities within this field, this review discusses the applications of long range rulers for monitoring biological and chemical processes. At the end, we conclude by speculating on the role of long range optical rulers in future scientific research and discuss possible problems, outlooks and future needs in the use of optical rulers for technological applications.


Asunto(s)
Transferencia Resonante de Energía de Fluorescencia/métodos , Nanotecnología/métodos , Fenómenos Ópticos , Animales , Humanos , Espectrometría Raman
8.
Int J Med Microbiol ; 304(3-4): 351-9, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24462008

RESUMEN

The ShlA hemolysin of Serratia marcescens is secreted across the outer membrane by the ShlB protein; ShlB belongs to the two-partner secretion system (type Vb), a subfamily of the Omp85 outer membrane protein assembly and secretion superfamily. During secretion, ShlA is converted from an inactive non-hemolytic form into an active hemolytic form. The structure of ShlB is predicted to consist of the N-terminal α-helix H1, followed by the two polypeptide-transport-associated domains POTRA P1 and P2, and the ß-barrel of 16 ß-strands. H1 is inserted into the pore of the ß-barrel in the outer membrane; P1 and P2 are located in the periplasm. To obtain insights into the secretion and activation of ShlA by ShlB, we isolated ShlB mutants impaired in secretion and/or activation. The triple H1 P1 P2 mutant did not secrete ShlA. The P1 and P2 deletion derivatives secreted reduced amounts of ShlA, of which P1 showed some hemolysis, whereas P2 was inactive. Deletion of loop 6 (L6), which is conserved among exporters of the Omp85 family, compromised activation but retained low secretion. Secretion-negative mutants generated by random mutagenesis were located in loop 6. The inactive secreted ShlA derivatives were complemented in vitro to active ShlA by an N-terminal ShlA fragment (ShlA242) secreted by ShlB. Deletion of H1 did not impair secretion of hemolytic ShlA. The study defines domains of ShlB which are important for ShlA secretion and activation.


Asunto(s)
Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/metabolismo , Serratia marcescens/genética , Serratia marcescens/metabolismo , Secuencia de Aminoácidos , Proteínas Bacterianas/química , Prueba de Complementación Genética , Proteínas Hemolisinas/química , Modelos Moleculares , Datos de Secuencia Molecular , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Mutación , Conformación Proteica , Eliminación de Secuencia
9.
Tetrahedron Lett ; 55(8): 1467-1470, 2014 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-24753636

RESUMEN

A new quinoline-based tripodal thiourea has been synthesized, which exclusively binds fluoride anion in DMSO, showing no affinity for other anions including, chloride, bromide, iodide, perchlorate, nitrate and hydrogen sulfate. As investigated by 1H NMR, the receptor forms both 1:1 and 1:2 complex yielding the binding constants of 2.32(3) (in log ß1 ) and 4.39(4) (in log ß2 ), respectively; where quinoline groups are protonated by the fluoride-induced proton transfer from the solution to the host molecule. The 1:2 binding is due to the interactions of one fluoride with NH binding sites of urea sites and another fluoride with secondary +NH binding sites within the tripodal pocket. The formation of both 1:1 and 1:2 complexes has been confirmed by the theoretical calculations based on density functional theory (DFT).

10.
Sci Total Environ ; 945: 174078, 2024 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-38906279

RESUMEN

This paper investigates the potential of graphene-coated sand (GCS) as an advanced filtration medium for improving water quality and mitigating chemicals of emerging concern (CECs) in treated municipal wastewater, aiming to enhance water reuse. The study utilizes three types of sand (Ottawa, masonry, and concrete) coated with graphene to assess the impact of surface morphology, particle shape, and chemical composition on coating and filtration efficiency. Additionally, sand coated with graphene and activated graphene coated sand were both tested to understand the effect of coating and activation on the filtration process. The materials were characterized using digital microscopy, Raman spectroscopy, scanning electron microscopy (SEM), and X-ray diffraction analysis. The material's efficiency in removing turbidity, nutrients, chemical oxygen demand (COD), bacteria, and specific CECs (Aciclovir, Diatrizoic acid, Levodopa, Miconazole, Carbamazepine, Diphenhydramine, Irbesartan, Lidocaine, Losartan, and Sulfamethoxazole) was studied. Our findings indicate that GCS significantly improves water quality parameters, with notable efficiency in removing turbidity, COD (14.1 % and 69.1 % removal), and bacterial contaminants (64.9 % and 99.9 % removal). The study also highlights the material's capacity to remove challenging CECs like Sulfamethoxazole (up to 80 % removal) and Diphenhydramine (up to 90 % removal), showcasing its potential as a sustainable solution for water reuse applications. This research contributes to the field by providing a comprehensive evaluation of GCS in water treatment, suggesting its potential for removing CECs from treated municipal wastewater.

11.
ACS Omega ; 9(29): 32256-32267, 2024 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-39072127

RESUMEN

Superbug infections are currently one of the biggest global health problems in our society. Herein, we report the design of a plasmonic gold nanoparticle (GNP)-decorated WO3 nanowire-based heterojunction for the proficient usage of sunlight-based renewable energy to inactivate 100% superbugs via photothermally boosted photocatalytic action. Additionally, a synergistic photothermal and photocatalytic approach has been used for sunlight-driven complete eradication of carbapenem-resistant Enterobacteriaceae Escherichia coli (CRE E. coli) and methicillin-resistant Staphylococcus aureus (MRSA) superbugs. Interestingly, photocatalytic activity of methylene blue (MB) dye degradation in the presence of 670 nm near-infrared light shows that photothermally boosted photocatalytic performance is much superior to that of only a photocatalytic or photothermal process. The observed higher photocatalytic performance for the heterojunction is because the plasmonic GNP enhanced the absorption capability at 670 nm and increased the temperature of the photocatalyst surface, which reduces the activation energy of the degradation reaction. Similarly, sunlight-driven photocatalytic experiments show 100% degradation of MB after 60 min of sunlight irradiation. Moreover, sunlight-based photocatalytic inactivation of MRSA and CRE E. coli experiments show 100% inactivation after 60 min of light irradiation.

12.
Acta Crystallogr Sect E Struct Rep Online ; 69(Pt 12): m643-4, 2013 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-24454160

RESUMEN

In the centrosymmetric trinuclear Zn(II)⋯Ca(II)⋯Zn(II) title complex, [CaZn2(CH3COO)6(C12H12N2)2], the Ca(II) ion lies on an inversion centre and is octa-hedrally coordinated by six acetate O atoms. The Zn(II) ion is coordinated by two N atoms from a bidentate di-methyl-bipyridine ligand and three O atoms from acetate ligands bridging to the Ca(II) ion, leading to a distorted square-pyramidal coordination sphere. The Zn⋯Ca distance is 3.4668 (5) Å.

13.
Biochem Pharmacol ; 215: 115689, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37481132

RESUMEN

Pseudomonas aeruginosa can utilize various virulence factors necessary for host infection and persistence. These virulence factors include pyocyanin, proteases, exotoxins, 2-heptyl-4-hydroxyquinoline N-oxide (HQNO), phospholipases, and siderophores that enable the bacteria to cause severe infections in immunocompromised individuals. P. aeruginosa falls into the category of nosocomial pathogens that are typically resistant to available antibiotics and therapeutic approaches. P. aeruginosa bio-film formation is a major concern in hospitals because it can cause chronic infection and increase the risk of mortality. Therefore, the development of new strategies to disrupt biofilm formation and improve antibiotic efficacy for the treatment of P. aeruginosa infections is crucial. Anti-biofilm and anti-quorum sensing (QS) activity can be viewed as an anti-virulence approach to control the infectious nature of P. aeruginosa. Inhibition of QS and biofilm formation can be achieved through pharmacological approaches such as phytochemicals and essential oils, which have shown promising results in laboratory studies. A regulatory protein called LasR plays a key role in QS signaling to coordinate gene expression. Designing an antagonist molecule that mimics the natural autoinducer might be the best approach for LasR inhibition. Here we reviewed the mechanism behind antibiotic resistance and alternative approaches to combat the pathogenicity of P. aeruginosa.


Asunto(s)
Pseudomonas aeruginosa , Transducción de Señal , Humanos , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Biopelículas , Agregación Celular
14.
J Photochem Photobiol B ; 240: 112652, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36682344

RESUMEN

The majority of nosocomial infections are caused by bacteria with antimicrobial resistance and the formation of biofilms, such as implant-related bacterial infections and sepsis. There is an urgent need to develop new strategies for early-stage screening, destruction of multidrug-resistant bacteria, and efficient inhibition of biofilms. Organic dyes that absorb and emit in the near-infrared (NIR) region are potentially non-invasive, high-resolution, and rapid biological imaging materials. In this study, a non-toxic and biocompatible indolizine squaraine dye with water-solubilizing sulfonate groups (SO3SQ) is studied for bacterial imaging and photothermal therapy (PTT). PTT is efficient in eliminating microorganisms through local hyperthermia without the risk of developing drug-resistant bacteria. The optical properties of SO3SQ are studied extensively in phosphate-buffered saline (PBS). UV-Vis-NIR absorption spectra analysis shows a strong absorption between 650 nm - 1000 nm. SO3SQ allows for the wash-free fluorescence imaging of drug-resistant bacteria via NIR fluorescence imaging due to a "turn-on" fluorescence property of the dye when interacting with bacteria. Although SO3SQ exhibits no toxicity against both Gram-positive bacteria and Gram-negative bacteria, the PTT property of SO3SQ is efficient in killing bacteria as well as inhibiting and eradicating biofilms. PTT experiments demonstrate that SO3SQ reduces 90% of cell viability in bacterial strains under NIR radiation with a minimum inhibition concentration (MIC90) of >450 µg/mL. The PTT property of SO3SQ can also inhibit biofilms (BIC90 = 1000-2000 µg/mL) and eradicate both preformed young and mature biofilms (MBEC90 = 1500-2000 µg/mL) as observed by crystal violet assays.


Asunto(s)
Indolizinas , Fototerapia , Fototerapia/métodos , Antibacterianos/farmacología , Antibacterianos/química , Bacterias , Imagen Óptica , Biopelículas , Indolizinas/farmacología
15.
ACS Omega ; 8(14): 13202-13212, 2023 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-37065067

RESUMEN

Despite black cubic phase α-CsPbI3 nanocrystals having an ideal bandgap of 1.73 eV for optoelectronic applications, the phase transition from α-CsPbI3 to non-perovskite yellow δ-CsPbI3 phase at room temperature remains a major obstacle for commercial applications. Since γ-CsPbI3 is thermodynamically stable with a bandgap of 1.75 eV, which has great potential for photovoltaic applications, herein we report a conceptually new method for the targeted design of phase stable and near unity photoluminescence quantum yield (PLQY) two-dimensional (2D) γ-CsPbI3 nanoplatelets (NPLs) and one-dimensional (1D) γ-CsPbI3 nanobelts (NBs) by wavelength dependent light-induced assembly of CsPbI3 cubic nanocrystals. This article demonstrates for the first time that by varying the excitation wavelengths, one can design air stable desired 2D nanoplatelets or 1D nanobelts selectively. Our experimental finding indicates that 532 nm green light-driven self-assembly produces phase stable and highly luminescent γ-CsPbI3 NBs from CsPbI3 nanocrystals. Moreover, we show that a 670 nm red light-driven self-assembly process produces stable and near unity PLQY γ-CsPbI3 NPLs. Systematic time-dependent microscopy and spectroscopy studies on the morphological evolution indicates that the electromagnetic field of light triggered the desorption of surface ligands from the nanocrystal surface and transformation of crystallographic phase from α to γ. Detached ligands played an important role in determining the morphologies of final structures of NBs and NPLs from nanocrystals via oriented attachment along the [110] direction initially and then the [001] direction. In addition, XRD and fluorescence imaging data indicates that both NBs and NPLs exhibit phase stability for more than 60 days in ambient conditions, whereas the cubic phase α-CsPbI3 nanocrystals are not stable for even 3 days. The reported light driven synthesis provides a simple and versatile approach to obtain phase pure CsPbI3 for possible optoelectronic applications.

16.
ACS Appl Bio Mater ; 6(2): 919-931, 2023 02 20.
Artículo en Inglés | MEDLINE | ID: mdl-36746648

RESUMEN

The rapid emergence of superbugs which are resistant to existing antibiotics is becoming a huge global threat to public health, which demands the discovery of next-generation antibacterial agents for combating superbugs. Herein, we report the design of a two-dimensional (2D) reduced graphene oxide (r-GO) and one-dimensional (1D) WO3 nanowire-based photothermal-photocatalytic heterostructure for combating multiantibiotic-resistant Salmonella DT104, carbapenem-resistant Enterobacteriaceae Escherichia coli, and methicillin-resistant Staphylococcus aureus superbugs. In the presence of near-infrared (NIR) light, due to the generation of electrons and holes, the WO3-based heterostructure generates reactive oxygen species by photocatalytic reaction from water and oxygen, which kills superbugs. To enhance the photocatalytic superbug killing efficiency, r-GO has been used for suppressing the recombination of the photoinduced electron-hole pairs. Reported data show that NIR light-driven synergistic photocatalytic-photothermal processes can be used for 100% degradation of methylene blue using a heterostructure-based catalyst, and the photodegradation rate for the heterostructure is much better than the literature data for different types of WO3/GO-based nanocomposites. Experimentally, time-dependent antibacterial efficiency data reveals that the heterostructure can destroy 100% superbugs within 30 min of light exposure via a synergistic photothermal and photocatalytic mechanism, whereas the WO3 nanowire can kill around 35% superbugs only via photocatalytic action only and r-GO can kill 25% superbugs via photothermal action even after 30 min of exposure to light. Systematic time-dependent microscopy and spectroscopy studies reveal that the excellent antisuperbug activities for heterostructures are due to membrane damage, ATP, and DNA/RNA breakage. For possible real-life applications, sun light-based superbug inactivation shows 100% inactivation possible within 250 min of light exposure using 12 mg/mL heterostructures. The reported sun light-driven killing of superbugs provides a simple and versatile platform to combat drug-resistant superbugs.


Asunto(s)
Staphylococcus aureus Resistente a Meticilina , Nanocables , Especies Reactivas de Oxígeno/metabolismo , Antibacterianos/farmacología , Antibacterianos/química
17.
ACS Omega ; 8(47): 44942-44954, 2023 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-38046318

RESUMEN

Although water is essential for life, as per the United Nations, around 2 billion people in this world lack access to safely managed drinking water services at home. Herein we report the development of a two-dimensional (2D) fluorinated graphene oxide (FGO) and polyethylenimine (PEI) based three-dimensional (3D) porous nanoplatform for the effective removal of polyfluoroalkyl substances (PFAS), pharmaceutical toxins, and waterborne pathogens from contaminated water. Experimental data show that the FGO-PEI based nanoplatform has an estimated adsorption capacity (qm) of ∼219 mg g-1 for perfluorononanoic acid (PFNA) and can be used for 99% removal of several short- and long-chain PFAS. A comparative PFNA capturing study using different types of nanoplatforms indicates that the qm value is in the order FGO-PEI > FGO > GO-PEI, which indicates that fluorophilic, electrostatic, and hydrophobic interactions play important roles for the removal of PFAS. Reported data show that the FGO-PEI based nanoplatform has a capability for 100% removal of moxifloxacin antibiotics with an estimated qm of ∼299 mg g-1. Furthermore, because the pore size of the nanoplatform is much smaller than the size of pathogens, it has a capability for 100% removal of Salmonella and Escherichia coli from water. Moreover, reported data show around 96% removal of PFAS, pharmaceutical toxins, and pathogens simultaneously from spiked river, lake, and tap water samples using the nanoplatform.

18.
ACS Appl Bio Mater ; 6(6): 2446-2458, 2023 06 19.
Artículo en Inglés | MEDLINE | ID: mdl-37267204

RESUMEN

Due to the lack of early detection before metastasis and failure of current therapy to cure the disease, lung cancer contributes to the highest cancer-related mortality worldwide. Tenascin C (TNC) (+) exosomes promote metastasis, amphiregulin (AREG) (+) exosomes are associated with chemotherapy resistance, and programmed cell death ligand-1 (PDL-1) (+) exosomes are associated with immunotherapy resistance, and they are emerging as biomarkers in clinics. However, due to heterogeneity, rapid isolation and multiplex detection of these exosomes are challenging. Herein, we report the design of an antibody-conjugated multi-color (orange, yellow, and green)-emissive carbon dot (CD)-attached cobalt spinel ferrite (CoFe2O4)-based magneto-luminescent nanoarchitecture for targeted capturing and identification of TNC (+), AREG (+), and PDL-1(+) exosomes selectively and simultaneously from whole blood samples. More importantly, to capture and identify the targeted AREG (+) exosome from an infected whole-blood sample, an anti-AREG antibody-attached green (520 nm)-emissive CD-conjugated CoFe2O4 nanoparticle-based magnetic-green luminescence nanoarchitecture was developed. Similarly, an anti-PDL-1 antibody-attached orange (600 nm)-emissive CDs-based magnetic-orange luminescence nanoarchitecture has been produced to capture and identify the PDL-1 (+) exosome. Furthermore, an anti-TNC antibody-attached yellow (560 nm)-emissive CD-based magnetic-orange luminescent nanoarchitecture has been designed to capture and identify the TNC (+) exosome. Notably, our finding reveals that 100% TNC (+) exosomes can be captured and imaged selectively from an infected blood sample using an anti-TNC antibody-conjugated nanoarchitecture. In addition, 100% AREG (+) exosomes can be captured and imaged selectively using an anti-AREG antibody-conjugated nanoarchitecture. Moreover, 100% PDL-1 (+) exosomes can be captured and imaged selectively using an anti-PDL-1 antibody-conjugated nanoarchitecture. Furthermore, we have demonstrated that a multi-color-emissive nanoarchitecture can be used for capturing and imaging all three exosomes simultaneously.


Asunto(s)
Exosomas , Neoplasias Pulmonares , Nanopartículas , Humanos , Exosomas/metabolismo , Luminiscencia , Neoplasias Pulmonares/metabolismo , Biomarcadores/metabolismo
19.
ACS Nano ; 17(20): 20262-20272, 2023 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-37830778

RESUMEN

Dielectric capacitors are critical components in electronics and energy storage devices. The polymer-based dielectric capacitors have the advantages of device flexibility, fast charge-discharge rates, low loss, and graceful failure. Elevating the use of polymeric dielectric capacitors for advanced energy applications such as electric vehicles (EVs), however, requires significant enhancement of their energy densities. Here, we report a polymer thin film heterostructure-based capacitor of poly(vinylidene fluoride)/poly(methyl methacrylate) with stratified 2D nanofillers (Mica or h-BN nanosheets) (PVDF/PMMA-2D fillers/PVDF), that shows enhanced permittivity, high dielectric strength, and an ultrahigh energy density of ≈75 J/cm3 with efficiency over 79%. Density functional theory calculations verify the observed permittivity enhancement. This approach of using oriented 2D nanofillers-based polymer heterostructure composites is expected to be versatile for designing high energy density thin film polymeric dielectric capacitors for myriads of applications.

20.
J Am Chem Soc ; 134(29): 11892-5, 2012 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-22765503

RESUMEN

We present an unprecedented fluoride-water cyclic cluster of [F(H(2)O)](4)(4-) assembled in a cuboid molecular box formed by two large macrocycles. Structural characterization reveals that [F(H(2)O)](4)(4-) is assembled by strong H-bonding interactions [OH···F = 2.684(3)-2.724(3) Å], where a fluoride anion plays the topological role of a water molecule in the classical cyclic water octamer. The interaction of fluoride was further confirmed by (19)F NMR and (1)H NMR spectroscopies, indicating the encapsulation of the anionic species within the cavity in solution. High-level DFT calculations and Bader topological analyses fully support the crystallographic results, demonstrating that the bonding arrangement in the fluoride-water cluster arises from the unique geometry of the host.


Asunto(s)
Fluoruros/química , Compuestos Macrocíclicos/química , Agua/química , Aniones/química , Enlace de Hidrógeno , Espectroscopía de Resonancia Magnética , Modelos Moleculares
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