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2.
Exp Hematol Oncol ; 13(1): 85, 2024 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-39160631

RESUMEN

Epstein-Barr virus (EBV) related post-transplant lymphoproliferative disorder (EBV-PTLD) is a life-threatening complication after hematopoietic stem cell transplantation (HSCT) or solid organ transplantation (SOT), for which no standard therapeutic means have been developed. Significant increase expression of natural killer group 2 member D ligands (NKG2DLs) was observed on B-lymphoblastoid cells of EBV-PTLD, indicating NKG2DLs as potential therapeutic targets for treatment of EBV-PTLD. In this study, the recombinant constructs of NKG2D CAR and IL-15/IL-15Rα-NKG2D CAR were generated with a retroviral vector and then transduced to human T cells to produce NKG2D CAR-T and IL-15/IL-15Rα-NKG2D CAR-T cells, respectively. B-lymphoblastoid cell lines (B-LCLs) and the xenografted mouse models were established to evaluate the efficacy of these CAR-T cells. IL-15/IL-15Rα-NKG2D CAR-T cells exhibited superior proliferation and antigen-specific cytotoxic effect compared to NKG2D CAR-T, as IL-15/IL-15Rα signaling promoted the expansion of less differentiated central memory T cells (TCM) and increased expression of CD107a and IFN-γ. Moreover, EBV DNA load was dramatically reduced, and 80% B-LCL cells were eliminated by IL-15/IL-15Rα-NKG2D CAR-T cells after co-culturing. In-vivo study confirmed that IL-15/IL-15Rα-NKG2D CAR-T cell therapy significantly enhanced antiviral efficacy in mice, as the serum load of EBV after IL-15/IL-15Rα-NKG2D CAR-T cell infusion was 1500 times lower than the untreated control (P < 0.001). The enhanced efficacy of IL-15/IL-15Rα-NKG2D CAR T cells was probably due to the IL-15/IL-15Rα signaling improved homing and persistence of NKG2D CAR-T cells in vivo, and increased the production of IFN-γ, Perforin, and Granulysin. In conclusion, NKG2D CAR-T cells co-expressing IL-15/IL-15Rα promoted the central memory CAR T cell proliferation and improved the homing and persistence of CAR T cells in vivo, resulting in enhanced anti-tumor and anti-viral effects in treating EBV-PTLD.

3.
Elife ; 132024 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-39163210

RESUMEN

1-Naphthylamine (1NA), which is harmful to human and aquatic animals, has been used widely in the manufacturing of dyes, pesticides, and rubber antioxidants. Nevertheless, little is known about its environmental behavior and no bacteria have been reported to use it as the growth substrate. Herein, we describe a pathway for 1NA degradation in the isolate Pseudomonas sp. strain JS3066, determine the structure and mechanism of the enzyme NpaA1 that catalyzes the initial reaction, and reveal how the pathway evolved. From genetic and enzymatic analysis, a five gene-cluster encoding a dioxygenase system was determined to be responsible for the initial steps in 1NA degradation through glutamylation of 1NA. The γ-glutamylated 1NA was subsequently oxidized to 1,2-dihydroxynaphthalene which was further degraded by the well-established pathway of naphthalene degradation via catechol. A glutamine synthetase-like (GS-like) enzyme (NpaA1) initiates 1NA glutamylation, and this enzyme exhibits a broad substrate selectivity toward a variety of anilines and naphthylamine derivatives. Structural analysis revealed that the aromatic residues in the 1NA entry tunnel and the V201 site in the large substrate-binding pocket significantly influence NpaA1's substrate preferences. The findings enhance understanding of degrading polycyclic aromatic amines, and will also enable the application of bioremediation at naphthylamine contaminated sites.


Asunto(s)
1-Naftilamina , Pseudomonas , Pseudomonas/enzimología , Pseudomonas/genética , Pseudomonas/metabolismo , Especificidad por Sustrato , 1-Naftilamina/análogos & derivados , 1-Naftilamina/metabolismo , Biodegradación Ambiental , Dioxigenasas/metabolismo , Dioxigenasas/genética , Dioxigenasas/química , Redes y Vías Metabólicas , Familia de Multigenes , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/química
4.
Nano Lett ; 24(31): 9720-9726, 2024 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-39051601

RESUMEN

Surface plasmons excited via inelastic tunnelling have led to plasmon light sources with small footprints and ultrafast response speeds, which are favored by integrated optical circuits. Self-assembled monolayers of organic molecules function as highly tunable tunnel barriers with novel functions. However, limited by the low effective contact between the liquid metal electrode and the self-assembled monolayers, it is quite challenging to obtain molecular plasmon light sources with high density and uniform emission. Here, by combining lithographic patterning with a solvent treatment method, we have demonstrated electrically driven deterministic plasmon emission from arrays of molecular tunnel junctions. The solvent treatment could largely improve the effective contact from 9.6% to 48% and simultaneously allow the liquid metal to fill into lithographically patterned micropore structures toward deterministic plasmon emission with desired patterns. Our findings open up new possibilities for tunnel junction-based plasmon light sources, laying the foundation for electrically driven light-emitting metasurfaces.

5.
Gene ; 927: 148634, 2024 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-38848880

RESUMEN

BACKGROUND: B cell exhaustion (BEX) refers to the impairment of normal B cell functions and decreased proliferation capability. However, the prognostic value of BEX-related genes in bladder cancer (BLCA) remains unclear. METHODS: BLCA cases from TCGA were used for training, while GSE5287, GSE13507, GSE31684, and GSE32894 cohorts from GEO were used for external validation. BEX-related genes were identified through literature retrieval, unsupervised clustering, and genomic difference detection. Gene pairing, LASSO, random forest, and Cox regression were employed to construct a predictive model. B cell samples from scRNAseqDB, GSE111636, and IMvigor210 were utilized to explore immunoprofiles and the predictive ability of the model in immunotherapeutic response. Additionally, 21 pairs of BLCA and paracarcinoma samples from Nanfang Hospital were used to re-confirm our findings through RT-qPCR, immunofluorescence, and flow cytometry. RESULTS: 39 BEX-related genes were identified. A 4-gene-pair signature was constructed and served as a reliable prognostic predictor across multiple datasets (pooled HR = 2.32; 95 % CI = 1.81-2.98). The signature reflected the BEX statuses of B cells (FDR < 0.05) and showed promise in evaluating immunotherapeutic sensitivity (P < 0.001). In the local cohort, CD52, TUBB6, and CAV1 were down-regulated in BLCA tissues, while TGFBI, UBE2L6, TINAGL1, and IL32 were up-regulated (all P < 0.05). Furthermore, the infiltration levels of CD19 + CD52 + and CD19 + TUBB6 + B cells in paracarcinoma samples were higher than those in BLCA samples (all P < 0.05). CONCLUSION: A BEX-related gene signature was developed to predict prognosis and immunotherapeutic sensitivity in BLCA, providing valuable guidance for personalized treatment.


Asunto(s)
Linfocitos B , Inmunoterapia , Neoplasias de la Vejiga Urinaria , Neoplasias de la Vejiga Urinaria/genética , Neoplasias de la Vejiga Urinaria/inmunología , Humanos , Pronóstico , Linfocitos B/inmunología , Linfocitos B/metabolismo , Biomarcadores de Tumor/genética , Regulación Neoplásica de la Expresión Génica , Masculino , Femenino , Perfilación de la Expresión Génica/métodos , Transcriptoma , Persona de Mediana Edad , Agotamiento del Sistema Inmunológico
6.
J Exp Clin Cancer Res ; 43(1): 101, 2024 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-38566204

RESUMEN

BACKGROUND: Regulatory B cells (Bregs), a specialized subset of B cells that modulate immune responses and maintain immune tolerance in malignant tumors, have not been extensively investigated in the context of bladder cancer (BLCA). This study aims to elucidate the roles of Bregs and Breg-related genes in BLCA. METHODS: We assessed Breg infiltration levels in 34 pairs of BLCA and corresponding paracancerous tissues using immunohistochemical staining. We conducted transwell and wound healing assays to evaluate the impact of Bregs on the malignant phenotype of SW780 and T24 cells. Breg-related genes were identified through gene sets and transcriptional analysis. The TCGA-BLCA cohort served as the training set, while the IMvigor210 and 5 GEO cohorts were used as external validation sets. We employed LASSO regression and random forest for feature selection and developed a risk signature using Cox regression. Primary validation of the risk signature was performed through immunohistochemical staining and RT-qPCR experiments using the 34 local BLCA samples. Additionally, we employed transfection assays and flow cytometry to investigate Breg expansion ability and immunosuppressive functions. RESULTS: Breg levels in BLCA tissues were significantly elevated compared to paracancerous tissues (P < 0.05) and positively correlated with tumor malignancy (P < 0.05). Co-incubation of SW780 and T24 cells with Bregs resulted in enhanced invasion and migration abilities (all P < 0.05). We identified 27 Breg-related genes, including CD96, OAS1, and CSH1, which were integrated into the risk signature. This signature demonstrated robust prognostic classification across the 6 cohorts (pooled HR = 2.25, 95% CI = 1.52-3.33). Moreover, the signature exhibited positive associations with advanced tumor stage (P < 0.001) and Breg infiltration ratios (P < 0.05) in the local samples. Furthermore, the signature successfully predicted immunotherapeutic sensitivity in three cohorts (all P < 0.05). Knockdown of CSH1 in B cells increased Breg phenotype and enhanced suppressive ability against CD8 + T cells (all P < 0.05). CONCLUSIONS: Bregs play a pro-tumor role in the development of BLCA. The Breg-related gene signature established in this study holds great potential as a valuable tool for evaluating prognosis and predicting immunotherapeutic response in BLCA patients.


Asunto(s)
Linfocitos B Reguladores , Neoplasias de la Vejiga Urinaria , Humanos , Neoplasias de la Vejiga Urinaria/genética , Neoplasias de la Vejiga Urinaria/terapia , Linfocitos T CD8-positivos , Citometría de Flujo , Inmunoterapia , Pronóstico
7.
J Hazard Mater ; 458: 131886, 2023 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-37348368

RESUMEN

Nitroanisoles are used widely as synthetic intermediates and explosives. Although bacteria have been reported to degrade 4-nitroanisole (4NA) under aerobic conditions, the key enzymes and the catalytic mechanism have remained elusive. Rhodococcus sp. strain JS3073 was isolated for its ability to grow on 4NA as the sole carbon and energy source. In this study, whole cell biotransformation experiments indicated that 4NA degradation is initiated by O-demethylation to form 4-nitrophenol (PNP), which undergoes subsequent degradation by a previously established pathway involving formation of 1,2,4-benzenetriol and release of nitrite. Based on comparative transcriptomics and heterologous expression, a novel three-component cytochrome P450 system encoded by pnaABC initiates the O-demethylation of 4NA to yield formaldehyde and PNP. The pnaABC genes encode a phthalate dioxygenase type reductase (PnaA), a cytochrome P450 monooxygenase (PnaB), and an EthD family protein (PnaC) with putative function similar to ferredoxins. This unusual P450 system also has a broad substrate specificity for nitroanisole derivatives. Sequence analysis of PnaAB revealed high identity with multiple self-sufficient P450s of the CYP116B subfamily. The findings revealed the molecular basis of the catabolic pathway for 4NA initiated by an unusual O-demethylase PnaABC and extends the understanding of the diversity among P450s and their electron transport chains.


Asunto(s)
Rhodococcus , Rhodococcus/metabolismo , Sistema Enzimático del Citocromo P-450/metabolismo , Anisoles/metabolismo , Biotransformación
8.
Front Immunol ; 14: 1130442, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37207215

RESUMEN

CD19 chimeric antigen receptor (CAR) engineered NK cells have been used for treating patients with relapsed and/or refractory B cell malignancies and show encouraging outcomes and safety profile. However, the poor persistence of NK cells remains a major challenge for CAR NK cell therapy. Memory-like NK cells (MLNK) induced by IL-12, IL-15, and IL-18 have shown enhanced and prolonged responses to tumor re-stimulation, making them an attractive candidate for adoptive cellular immunotherapy. Here, we show efficient and stable gene delivery of CD19 CAR to memory-like NK cells using retroviral vectors with transduction efficiency comparable to those achieved with conventional NK cells. Analysis of surface molecules revealed a distinct phenotypic profile in CAR engineered memory-like NK cells (CAR MLNK), as evidenced by increased expression of CD94 and downregulation of NKp30 as well as KIR2DL1. Compared to conventional CAR NK cells, CAR MLNK cells exhibited significantly increased IFN-γ production and degranulation in response to CD19+ target cells, resulting in enhanced cytotoxic activity against CD19+ leukemia cells and lymphoma cells. Furthermore, memory properties induced by IL-12/-15/-18 improved the in vivo persistence of CAR MLNK cells and significantly suppressed tumor growth in a exnograft mouse model of lymphoma, leading to prolonged survival of CD19+ tumor-bearing mouse. Altogether, our data indicate that CD19 CAR engineered memory-like NK cells exhibited superior persistence and antitumor activity against CD19+ tumors, which might be an attractive approach for treating patient with relapse or refractory B cell malignancies.


Asunto(s)
Linfoma , Receptores Quiméricos de Antígenos , Animales , Ratones , Receptores Quiméricos de Antígenos/metabolismo , Citocinas/metabolismo , Línea Celular Tumoral , Células Asesinas Naturales , Antígenos CD19 , Interleucina-12/genética , Interleucina-12/metabolismo
9.
Chem Rev ; 122(19): 15177-15203, 2022 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-35762982

RESUMEN

This Review focuses on the integration of plasmonic and dielectric metasurfaces with emissive or stimuli-responsive materials for manipulating light-matter interactions at the nanoscale. Metasurfaces, engineered planar structures with rationally designed building blocks, can change the local phase and intensity of electromagnetic waves at the subwavelength unit level and offers more degrees of freedom to control the flow of light. A combination of metasurfaces and nanoscale emitters facilitates access to weak and strong coupling regimes for enhanced photoluminescence, nanoscale lasing, controlled quantum emission, and formation of exciton-polaritons. In addition to emissive materials, functional materials that respond to external stimuli can be combined with metasurfaces to engineer tunable nanophotonic devices. Emerging metasurface designs including surface-functionalized, chemically tunable, and multilayer hybrid metasurfaces open prospects for diverse applications, including photocatalysis, sensing, displays, and quantum information.

10.
Proc Natl Acad Sci U S A ; 119(22): e2202621119, 2022 05 31.
Artículo en Inglés | MEDLINE | ID: mdl-35605124

RESUMEN

SignificanceMolecules interacting with metallic nanostructures can show tunable exciton-plasmon coupling, ranging from weak to strong. One factor that influences the interactions is the spatial organization of the molecules relative to the localized plasmon-enhanced electromagnetic fields. In this work, we show that the arrangement of aromatic dye molecules can be tuned within plasmonic hotspots by interfacial engineering of nanoparticle surfaces. By controlling the local chemical and physical interactions, we could modulate lasing thresholds. Surface-functionalized plasmonic metasurfaces open prospects for programmable light-matter interactions at the nanoscale.

12.
Appl Environ Microbiol ; 87(14): e0000721, 2021 06 25.
Artículo en Inglés | MEDLINE | ID: mdl-33990303

RESUMEN

4-Nitrophenol, a priority pollutant, is degraded by Gram-positive and Gram-negative bacteria via 1,2,4-benzenetriol (BT) and hydroquinone (HQ), respectively. All enzymes involved in the two pathways have been functionally identified. So far, all Gram-negative 4-nitrophenol utilizers are from the genera Pseudomonas and Burkholderia. But it remains a mystery why pnpG, an apparently superfluous BT 1,2-dioxygenase-encoding gene, always coexists in the catabolic cluster (pnpABCDEF) encoding 4-nitrophenol degradation via HQ. Here, the physiological role of pnpG in Burkholderia sp. strain SJ98 was investigated. Deletion and complementation experiments established that pnpG is essential for strain SJ98 growing on 4-nitrocatechol rather than 4-nitrophenol. During 4-nitrophenol degradation by strain SJ98 and its two variants (pnpG deletion and complementation strains), 1,4-benzoquinone and HQ were detected, but neither 4-nitrocatechol nor BT was observed. When the above-mentioned three strains (the wild type and complementation strains with 2,2'-dipyridyl) were incubated with 4-nitrocatechol, BT was the only intermediate detected. The results established the physiological role of pnpG that encodes BT degradation in vivo. Biotransformation analyses showed that the pnpA-deleted strain was unable to degrade both 4-nitrophenol and 4-nitrocatechol. Thus, the previously characterized 4-nitrophenol monooxygenase PnpASJ98 is also essential for the conversion of 4-nitrocatechol to BT. Among 775 available complete genomes for Pseudomonas and Burkholderia, as many as 89 genomes were found to contain the putative pnpBCDEFG genes. The paucity of pnpA (3 in 775 genomes) implies that the extension of BT and HQ pathways enabling the degradation of 4-nitrophenol and 4-nitrocatechol is rarer, more recent, and likely due to the release of xenobiotic nitroaromatic compounds. IMPORTANCE An apparently superfluous gene (pnpG) encoding BT 1,2-dioxygenase is always found in the catabolic clusters involved in 4-nitrophenol degradation via HQ by Gram-negative bacteria. Our experiments reveal that pnpG is not essential for 4-nitrophenol degradation in Burkholderia sp. strain SJ98 but instead enables its degradation of 4-nitrocatechol via BT. The presence of pnpG genes broadens the range of growth substrates to include 4-nitrocatechol or BT, intermediates from the microbial degradation of many aromatic compounds in natural ecosystems. In addition, the existence of pnpCDEFG in 11.6% of the above-mentioned two genera suggests that the ability to degrade BT and HQ simultaneously is ancient. The extension of BT and HQ pathways including 4-nitrophenol degradation seems to be an adaptive evolution for responding to synthetic nitroaromatic compounds entering the environment since the industrial revolution.


Asunto(s)
Proteínas Bacterianas/metabolismo , Burkholderia/enzimología , Catecoles/metabolismo , Dioxigenasas/metabolismo , Hidroquinonas/metabolismo , Nitrofenoles/metabolismo , Proteínas Bacterianas/genética , Biotransformación , Burkholderia/genética , Dioxigenasas/genética , Pseudomonas/enzimología , Pseudomonas/genética
13.
Appl Environ Microbiol ; 87(8)2021 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-33547060

RESUMEN

As a water-soluble polymer, the widely used polyvinyl alcohol (PVA) is produced from hydrolysis of polyvinyl acetate. Microbial PVA carbon backbone cleavage via a two-step reaction of dehydrogenation and hydrolysis has been well studied. Content of acetyl group is a pivotal factor affecting performance of PVA derivatives in industrial application, and deacetylation is a non-negligible part in PVA degradation. However, the genetic and biochemical studies of its deacetylation remain largely elusive. Here, Comamonas sp. strain NyZ500 was isolated for its capability of growing on acetylated PVA from activated sludge. A spontaneous PVA-utilization deficient mutant strain NyZ501 was obtained when strain NyZ500 was cultured in rich media. Comparative analysis between the genomes of these two strains revealed a fragment (containing a putative hydrolase gene dacApva ) deletion in NyZ501 and dacApva-complemented strain NyZ501 restored the ability to grow on PVA. DacApva, which shares 21% identity with xylan esterase AxeA1 from Prevotella ruminicola 23, is a unique deacetylase catalyzing the conversion of acetylated PVA and its derivatives to deacetylated counterparts. This indicates that strain NyZ500 utilizes acetylated PVA via acetate as a carbon source to grow. DacApva also possessed the deacetylation ability for acetylated xylan and the antibiotic intermediate 7-aminocephalosporanic acid (7ACA) but the enzymes for the above two compounds had no activities against PVA derivatives. This study enhanced our understanding of the diversity of microbial degradation of PVA and DacApva characterized here is also a potential biocatalyst for the eco-friendly biotransformation of PVA derivatives and other acetylated compounds.IMPORTANCE: Water-soluble PVA, which possesses a very robust ability to accumulate in the environment, has a very grave environmental impact due to its widespread use in industrial and household applications. On the other hand, chemical transformation of PVA derivatives is currently being carried out at high energy consumption and high pollution conditions using hazardous chemicals (such as NaOH, methanol) under high temperatures. The DacApva reported here performs PVA deacetylation under mild conditions, then it has a great potential to be developed into an eco-friendly biocatalyst for biotransformation of PVA derivatives. DacApva also has deacetylation activity for compounds other than PVA derivatives, which facilitates its development into a broad-spectrum deacetylation biocatalyst for production of certain desired compounds.

14.
Nano Lett ; 21(3): 1523-1529, 2021 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-33508199

RESUMEN

This paper reports that strongly coupled bimetallic core-shell nanoparticle arrays show photoelectrocatalytic activity for hydrogen evolution reactions (HER). We fabricated large-area Cu-Pt nanoparticle lattices by combining top-down lithography and solution-based chemistry. These coupled lattices support two different types of plasmon modes, localized surface plasmons from individual particles and surface lattice resonances (SLRs) from the 2D lattice, that increased HER catalytic activity under white-light illumination up to 60%. Comparing photoelectrocatalytic performances of the two plasmon modes at different wavelength ranges, we found that SLRs had two-fold activity enhancement over that from localized surface plasmons.

15.
Nanoscale ; 12(47): 23920-23928, 2020 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-33242039

RESUMEN

Wrinkling skin layers on pre-strained polymer sheets has drawn significant interest as a method to create reconfigurable surface patterns. Compared to widely studied metal or silica films, softer polymer skins are more tolerant to crack formation when the surface topography is tuned under applied strain. This Mini-review discusses recent progress in mechano-responsive wrinkles based on polymer skin materials. Control over the skin thickness with nanometer accuracy allows for tuning of the wrinkle wavelength and orientation over length scales from nanometer to micrometer regimes. Furthermore, soft skin layers enable texturing of two-dimensional electronic materials with programmable feature sizes and structural hierarchy because of the conformal adhesion to the substrates. Soft skin systems open prospects to tailor a range of surface properties via external stimuli important for applications such as smart windows, microfluidics, and nanoelectronics.

16.
Proc Natl Acad Sci U S A ; 117(38): 23380-23384, 2020 09 22.
Artículo en Inglés | MEDLINE | ID: mdl-32900952

RESUMEN

This paper reports how the spectral linewidths of plasmon resonances can be narrowed down to a few nanometers by optimizing the morphology, surface roughness, and crystallinity of metal nanoparticles (NPs) in two-dimensional (2D) lattices. We developed thermal annealing procedures to achieve ultranarrow surface lattice resonances (SLRs) with full-width at half-maxima linewidths as narrow as 4 nm from arrays of Au, Ag, Al, and Cu NPs. Besides annealing, we developed a chemical vapor deposition process to use Cu NPs as catalytic substrates for graphene growth. Graphene-encapsulated Cu NPs showed the narrowest SLR linewidths (2 nm) and were stable for months. These ultranarrow SLR nanocavity modes supported even narrower lasing emission spectra and high nonlinearity in the input-output light-light curves.

17.
ACS Nano ; 14(1): 166-174, 2020 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-31675210

RESUMEN

This paper reports a method to realize crack-free graphene wrinkles with variable spatial wavelengths and switchable orientations. Graphene supported on a thin fluoropolymer and prestrained elastomer substrate can exhibit conformal wrinkling after strain relief. The wrinkle orientation could be switched beyond the intrinsic fracture limit of graphene for hundreds of cycles of stretching and releasing without forming cracks. Mechanical modeling revealed that the fluoropolymer layer mediated the structural evolution of the graphene wrinkles without crack formation or delamination. Patterned fluoropolymer layers with different thicknesses produced wrinkles with controlled wavelengths and orientations while maintaining the mechanical integrity of graphene under high tensile strain.

18.
Nano Lett ; 19(8): 5640-5646, 2019 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-31268720

RESUMEN

This paper reports a scalable approach to achieve spatially selective graphene functionalization using multiscale wrinkles. Graphene wrinkles were formed by relieving the strain in thermoplastic polystyrene substrates conformally coated with fluoropolymer and graphene skin layers. Chemical reactivity of a fluorination process could be tuned by changing the local curvature of the graphene nanostructures. Patterned areas of graphene nanowrinkles and crumples followed by a single-process plasma reaction resulted in substrates with regions having different fluorination levels. Notably, conductivity of the functionalized graphene nanostructures could be locally tuned as a function of feature size without affecting the mechanical properties.

19.
ACS Nano ; 13(4): 4613-4620, 2019 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-30896920

RESUMEN

This paper describes a reconfigurable metalens system that can image at visible wavelengths based on arrays of coupled plasmonic nanoparticles. These lenses manipulated the wavefront and focused light by exciting surface lattice resonances that were tuned by patterned polymer blocks on single-particle sites. Predictive design of the dielectric nanoblocks was performed using an evolutionary algorithm to create a range of three-dimensional focusing responses. For scalability, we demonstrated a simple technique for erasing and writing the polymer nanostructures on the metal nanoparticle arrays in a single step using solvent-assisted nanoscale embossing. This reconfigurable materials platform enables tunable focusing with diffraction-limited resolution and offers prospects for highly adaptive, compact imaging.

20.
Nanoscale ; 11(2): 504-511, 2019 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-30543229

RESUMEN

Since 2D transition metal dichalcogenides (TMDs) exhibit strain-tunable bandgaps, locally confining strain can allow lateral manipulation of their band structure, in-plane carrier transport and optical transitions. Herein, we show that a single wrinkle (width = 10 nm-10 µm) on an MoS2 flake can induce confined uniaxial strain to reduce the local bandgap (40-60 meV per % deformation), producing a microscopic exciton funnel with an enhancement in photocurrent over flat MoS2 devices. This study also shows that wrinkles can spatially reconfigure the distribution of dopants and enhance the light absorption in the MoS2 layer via Fabry-Perot interference in its nanocavity. In the field-effect transistor studies on the MoS2 flat-wrinkle-flat device-structure, a higher carrier mobility and an improvement in the on/off ratio were exhibited in the devices with a single wrinkle. This phenomenon is attributed to the built-in potential induced by the bandgap reduction at the wrinkle site and the change in doping of the suspended wrinkle. The wrinkle-induced tunability of the local bandgap and manipulation of the spatial transport barriers, and the enhanced light absorption can enable development of next-generation electronic and optoelectronic devices guided by in-plane deformation of 2D nanomaterials.

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