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Functionalized and oxidized silicon nanosheets: Customized design for enhanced sensitivity towards relative humidity
摘要： The use of completely oxidized two-dimensional (2D) silicon nanosheets (SiNSs) represents a novel approach for the application of 2D silicon-based materials in the nanoelectronics field. Densely stacked and highly porous oxidized SiNSs (OSiNSs) act as a sensitive layer for humidity detection. Due to the oxidation-caused porosity of the SiNSs and the possibility functionalize the 2D surface with hydrophilic groups, this hybrid material exhibits an extremely good sensitivity towards relative humidity (RH). In this work, precise tuning of the SiNSs’ sensing properties by their functionalization is demonstrated. In particular, the modification with methacrylic acid (MAA) groups, leading to SiNS-MAA, and the subsequent deposition on interdigitated electrodes double the capacitance value in the range of 20-85%RH. These values were achieved after the full oxidation of SiNS-MAA in ambient conditions. The mentioned changes in capacitance are extremely high compared to the response of the so far known common polymer humidity sensors. Contrary to that, this response is neutralized when the SiNSs are functionalized with tert-butyl acrylic acid (tBMA), a rather hydrophobic functional group. The fabricated devices show, how the specific functionalization of SiNSs serves as a reliable tool to provide sensitivity towards RH. Similar approach, based on tuning the functionality, can be applied to achieve e.g., sensor array selectivity. For this purpose, the functional groups on the surface of the nanomaterial can be further modified. Additional molecules with sensitivities towards various surrounding conditions could be attached. Furthermore, these functional molecules can be used for subsequent (bio)molecule immobilization, which can serve as sensitive molecular groups towards surrounding substrates and gases. However, one of the main challenges in sensor technology is to find a highly selective solution: a sensor system capable to differentiate among different vapor species. The described strategy can serve as an access towards new and promising solutions, which can help to face this issue in modern nanomaterials-based technology.
关键词： two-dimensional materials,porous silicon,functionalization,silicon nanosheets,hybrid systems,moisture content
更新于2025-11-21 11:20:48
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Synthesis of π-conjugated poly(arylene)s by polycondensation of 1,4-bis(3-methylpyridin-2-yl)benzene and aryl dibromides through regiospecific C-H functionalization process
摘要： On the basis of the Ru-catalyzed regiospeci?c direct double arylation of benzene rings possessing 3-methylpyridin-2-yl substituents to produce 1-aryl-2-(3-methylpyridin-2-yl)benzene derivatives, the synthesis of poly(p-phenylene) derivatives having 2,5-bis(3-methylpyridin-2-yl) substituents is described. The reaction of 1,4-bis(3-methylpyridin-2-yl)benzene with bromobenzene (2 equiv) was carried out in the presence of [RuCl2(η6-C6H6)]2 (5 mol %) in 1-methyl-2-pyrrolidone at 120°C for 24 h to produce 1,4-bis(3-methylpyridin-2-yl)-2,5-diphenylbenzene in 99% yield as a sole product. Neither 2,6-diphenylated nor further phenylated products was produced under the examined conditions. This regiospeci?c double arylation process was then applied to the synthesis of π-conjugated polymers by use of aryl dibromides such as 1,4-dibromobenzene, 2,7-dibromo-9,9-dihexyl?uorene, and 2,5-dibromothiophene. For example, a polymer was obtained in 73% yield by using 1,4-dibromobenzene, whose Mn and Mw/Mn were estimated to be 3300 and 1.51, respectively. The bathochromic shift of the ultraviolet (UV)–visible absorption spectrum with respect to that of the model compound, 1,4-bis(3-methylpyridin-2-yl)-2,5-diphenylbenzene, indicated the extension of the π-conjugation. The blue ?uorescence was also observed for the polymer upon the UV irradiation.
关键词： C-H functionalization,direct double arylation,poly(arylene)s,π-conjugated polymers
更新于2025-11-19 16:46:39
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A Luminescent Metal-Organic Framework with Pre-Designed Functionalized Ligands as an Efficient Fluorescence Sensing for Fe3+ Ions
摘要： Metal-organic frameworks are a class of attractive materials for fluorescent sensing. Here, we report the exploration of fluorescent Zn-based amine/azine-functionalized MOF, TMU-17-NH2, ([Zn(NH2-BDC)(4-bpdb)].2DMF; NH2-BDC = amino-1,4-benzenedicarboxylic acid, 4-bpdb = 1,4-bis(4-pyridyl)-2,3-diaza-2,3-butadiene) for highly selective and sensitive detection of Fe3+ in DMF solution. TMU-17-NH2 shows fast recognition of Fe3+ ion with a response time of <1 min and detection limit of 0.7 μM (40 ppb), and the luminescence is completely quenched in 10-3 M DMF solution of Fe3+. Furthermore, the static quenching constant is calculated to be upper than 41000 M-1 by the fluorescence titration experiment in low concentration of Fe3+. No interferences from 250 μM As3+, Cd2+, Zn2+, Co3+, Ni2+, Cu2+, Pb2+, Mn2+ and Al3+ were found for the detection of Fe3+. The efficient fluorescent quenching effect is attributed to the photoinduced electron transfer between Fe3+ ions and the amino-functionalized ligand in this MOF. Moreover, the introduced azine N donors in the 4-bpdb ligand of TMU-17-NH2 additionally donate their lone-pair electrons to the Fe3+ ions, leading to significantly enhanced detection ability. Furthermore, the regenerated TMU-17-NH2 still has high selectivity for Fe3+ ions, which suggests that the functionalized TMU-17-NH2 is a promising luminescent probe for selectively sensing of Fe3+ ions.
关键词： Metal-Organic Frameworks,Sensing,Fluorescence,Functionalization,Fe3+
更新于2025-11-19 16:46:39
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A wet chemical method for black phosphorus thinning and passivation
摘要： Layered black phosphorus (BP) has been expected to be a promising material for future electronic and optoelectronic applications since its discovery. However, the difficulty in mass fabricating layered air-stable BP severely obstructs its potential industry applications. Here, we report a new BP chemical modification method to implement all-solution based mass production of layered air-stable BP. This method uses the combination of two electron-deficient reagents of 2,2,6,6-tetramethylpiperidinyl-N-oxyl (TEMPO) and triphenylcarbenium tetrafluorobor ([Ph3C]BF4) to accomplish thinning and/or passivation of BP in organic solvent. The field effect transistor and photo detection devices constructed from the chemically modified BP flakes exhibit enhanced performances with environmental stability up to four months. A proof-of-concept BP thin film transistor fabricated through the all-solution based exfoliation and modification displays air-stable and typical p-type transistor behavior. This all-solution based method improves the prospects of BP for industry applications.
关键词： triphenylcarbenium tetrafluorobor,black phosphorus,TEMPO,chemical thinning,covalent functionalization
更新于2025-11-14 17:04:02
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Solubilization of Carbon Nanotubes with Ethylene-Vinyl Acetate for Solution-Processed Conductive Films and Charge Extraction Layers in Perovskite Solar Cells
摘要： Carbon nanotube (CNT) solubilization via non-covalent wrapping of conjugated semiconducting polymers is a common technique used to produce stable dispersions for depositing CNTs from solution. Here, we report the use of a non-conjugated insulating polymer, ethylene vinyl acetate (EVA), to disperse multi- and single-walled CNTs (MWCNT and SWCNT) in organic solvents. We demonstrate that despite the insulating nature of the EVA, we can produce semitransparent films with conductivities of up to 34 S/cm. We show, using photoluminescence spectroscopy, that the EVA strongly binds to individual CNTs, thus making them soluble, preventing aggregation, and facilitating the deposition of high-quality films. To prove the good electronic properties of this composite, we have fabricated perovskite solar cells using EVA/SWCNTs and EVA/MWCNTs as selective hole contact, obtaining power conversion efficiencies of up to 17.1%, demonstrating that the insulating polymer does not prevent the charge transfer from the active material to the CNTs.
关键词： perovskite solar cells,carbon nanotubes,insulating polymer,conductive films,CNT polymer functionalization
更新于2025-11-14 15:25:21
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Antimicrobial photodynamic inactivation of fungal biofilm using amino functionalized mesoporus silica-rose bengal nanoconjugate against Candida albicans
摘要： Candida albicans is an opportunistic fungal pathogen that causes both superficial and systemic infection and an important candidate that contribute to high morbidity and mortality rates in immunocompromised patients. The ability of C. albicans to switch from yeast to filamentous form and thereby forming biofilms make them resistant to most of the antifungal drugs available today. Thus the development of more effective antifungal drugs are essential and crucial at this point of time. Antimicrobial photodynamic therapy is an alternative modality to treat such biofilm forming resistant strains. This study aims to investigate the enhanced efficiency of newly synthesized MSN-RB conjugate as an antimicrobial photosensitizer for antimicrobial photodynamic therapy against C. albicans. Functionalization of MSN with amino groups was performed to increase the dye loading capacity. Conjugation process of MSN-RB was confirmed using different techniques including UV–Vis spectroscopy, Fluorescent spectroscopy and FTIR analysis. A low power green laser 50 mW irradiation was applied (5 min) for activation of MSN-RB conjugate and RB against C. albicans biofilm and planktonic cell. The comparative study of MSN-RB conjugate and free RB on aPDT was evaluated using standard experimental procedures. Antibiofilm efficacy was determined using biofilm inhibition assay, cell viability, EPS quantification and CLSM studies. The results revealed that MSN-RB conjugate has a significant antimicrobial activity (88.62 ± 3.4%) and antibiofilm effect on C. albicans when compared to free dye after light irradiation. The MSN-RB conjugate based aPDT can be employed effectively in treatment of C. albicans infections.
关键词： Antimicrobial photodynamic therapy,Conjugation,Amino functionalization,Mesoporus silica nanoparticles,Lipid peroxidation,Anti-biofilm activity
更新于2025-09-23 15:23:52
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Optical properties of amine-functionalized graphene oxide
摘要： Important applications of graphene oxide (GO) its derivatives have been found in several areas: energy materials, water treatment, environmental, catalytic, photocatalytic, and biomedical technologies. Among them, the application of GO in optical biosensors has attracted ever-increasing interest in the past few years. In the present work, GO was amine-functionalized by a solvent-free one-step method with two aromatic amines: 1-aminopyrene (AP), and 2-aminofluorene (AF); and one aliphatic amine 1-octadecylamine (ODA). Particle size was estimated by field emission-scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). Optical properties have been evaluated by application of photoluminescence (PL), FTIR, UV–VIS, and Raman spectroscopy. As a result, this study offers an efficient way to tune the optical properties due to their amine functionalization, favoring the development of optoelectronic and biological applications using graphene-based materials in the future.
关键词： Amine functionalization,Optical properties,Sensors,Graphene oxide
更新于2025-09-23 15:23:52
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Cholesterol Functionalization of Gold Nanoparticles Enhances Photo-Activation of Neural Activity
摘要： Gold nanoparticles (AuNPs) attached to the extracellular leaflet of the plasma membrane of neurons can enable the generation of action potentials (APs) in response to brief pulses of light. Recently described techniques to stably bind AuNP bioconjugates directly to membrane proteins (ion channels) in neurons enable robust AP generation mediated by the photoexcited conjugate. However, a strategy that binds the AuNP to the plasma membrane in a non-protein-specific manner could represent a simple, single-step means of establishing light-responsiveness in multiple types of excitable neurons contained in the same tissue. Based on the ability of cholesterol to insert into the plasma membrane, here we test whether AuNP functionalization with linear dihydrolipoic acid-poly(ethylene) glycol (DHLA-PEG) chains that are distally terminated with cholesterol (AuNP-PEG-Chol) can enable light-induced AP generation in neurons. Dorsal root ganglion (DRG) neurons of rat were labelled with 20 nm diameter spherical AuNP-PEG-Chol conjugates wherein ~30% of the surface ligands (DHLA-PEG-COOH) were conjugated to PEG-Chol. Voltage recordings under current-clamp conditions showed that DRG neurons labeled in this manner exhibited a capacity for AP generation in response to microsecond and millisecond pulses of 532 nm light, a property attributable to the close tethering of AuNP-PEG-Chol conjugates to the plasma membrane facilitated by the cholesterol moiety. Light-induced AP and subthreshold depolarizing responses of the DRG neurons were similar to those previously described for AuNP conjugates targeted to channel proteins using large, multicomponent immunoconjugates. This likely reflected the AuNP-PEG-Chol’s ability, upon plasmonic light absorption and resultant slight and rapid heating of the plasma membrane, to induce a concomitant transmembrane depolarizing capacitive current. Notably, AuNP-PEG-Chol delivered to DRG neurons by inclusion in the buffer contained in the recording pipette/electrode enabled similar light-responsiveness, consistent with the activity of AuNP-PEG-Chol bound to the inner (cytofacial) leaflet of the plasma membrane. Our results demonstrate the ability of AuNP-PEG-Chol conjugates to confer timely stable and direct responsiveness to light in neurons. Further, this strategy represents a general approach for establishing excitable cell photosensitivity that could be of substantial advantage for exploring a given tissue’s suitability for AuNP-mediated photo-control of neural activity.
关键词： nanoparticle functionalization,cholesterol,action potential,neural photo-activation,optocapacitance,gold nanoparticles,photosensitivity,dorsal root ganglion cell
更新于2025-09-23 15:23:52
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Synthesis of ZnO nanowires/Au nanoparticles hybrid by a facile one-pot method and their enhanced NO2 sensing properties
摘要： ZnO nanowires (ZNWs) and ZnO nanowires/Au nanoparticles hybrid (Au-ZNWs) with various Au concentrations were synthesized by a facile one-pot hydrothermal method and characterized by XRD, SEM, TEM, XPS, and FTIR. The structural characterization results exhibited that Au nanoparticles were self-assembled onto the surface of ZNWs and the c-axis growth of ZNWs is suppressed by the addition of HAuCl4 in the synthesis of Au-ZNWs hybrid. Gas sensing properties demonstrated the favorite sensing performance could be achieved for 1 mol% Au-ZNWs compared to pure ZNWs and Au-ZNWs with other Au concentrations. The maximum response of 1 mol% Au-ZNWs to 1 ppm NO2 was 31.4 at 150 °C, which was nearly 4 times higher than 8.2 of pure ZNWs. And the shortest response and recovery times could also be achieved by 1 mol% Au-ZNWs in a wide range of operating temperature. Au-ZNWs with various Au concentrations showed better selectivity to NO2 than pure ZNWs. The mechanism of enhanced NO2 sensing performance of Au-ZNWs was investigated by the combination of electronic and chemical sensitizations via Au nanoparticles functionalization.
关键词： NO2,Nanowires,Gas sensor,Au functionalization,ZnO
更新于2025-09-23 15:23:52
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A promising family of fluorescent water-soluble aza-BODIPY dyes for in vivo molecular imaging
摘要： A new family of water-soluble and bioconjugatable aza-BODIPY fluorophores was designed and synthesized using a boron-functionalization strategy. These dissymmetric bis-ammonium aza-BODIPY dyes present optimal properties for a fluorescent probe, i.e. they are highly water-soluble, very stable in physiological medium, they do not aggregate in PBS, possess high quantum yield and finally they can be easily bioconjugated to antibodies. Preliminary in vitro and in vivo studies were performed for one of these fluorophores to image PD-L1 (Programmed Death-Ligand 1), highlighting the high potential of these new probes for future in vivo optical imaging studies.
关键词： molecular Imaging,Fluorescent probes,boron functionalization,aza-BODIPY,Water-soluble fluorophores
更新于2025-09-23 15:23:52