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1.
Genes (Basel) ; 15(3)2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38540405

RESUMO

BACKGROUND: Among aneuploidies compatible with life, trisomy 22 mosaicism is extremely rare, and only about 25 postnatal and 18 prenatal cases have been described in the literature so far. The condition is mainly characterized by facial and body asymmetry, cardiac heart defects, facial dysmorphisms, growth failure, delayed puberty, and variable degrees of neurodevelopmental delay. PROBLEM: The scattered information regarding the condition and the dearth of data on its natural history and developmental outcomes restrict genetic counseling, particularly in prenatal settings. Moreover, a prompt diagnosis is frequently delayed by the negative selection of trisomic cells in blood, with mosaicism percentage varying among tissues, which often entails the need for further testing. Purpose/topic: The aim of our work is to provide assistance in prenatal and postnatal genetic counseling by systematically delineating the current knowledge of the condition. This entails defining the prenatal and postnatal characteristics of the condition and presenting novel data from three cases, both prenatally and postnatally. Additionally, we report the developmental outcomes observed in two new patients.


Assuntos
Transtornos Cromossômicos , Mosaicismo , Diagnóstico Pré-Natal , Dissomia Uniparental , Gravidez , Feminino , Humanos , Trissomia/genética , Cromossomos Humanos Par 22
2.
Eur J Ophthalmol ; 34(1): 30-38, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37016744

RESUMO

Ocular toxoplasmosis, a disease of the eye caused by the protozoan parasite Toxoplasma gondii, represents a common cause of posterior uveitis. The Authors review the current Literature regarding the uncommon presentation of ocular toxoplasmosis as macular serous retinal detachment (SRD). It is imperative to keep in mind that inflammatory SRD is a possible presentation of toxoplasmic retinochoroiditis. Underestimation of this clinical scenario and treatment with steroids alone without appropriate antiparasitic drugs, could lead to devastating consequences.


Assuntos
Descolamento Retiniano , Toxoplasma , Toxoplasmose Ocular , Uveíte Posterior , Humanos , Toxoplasmose Ocular/complicações , Toxoplasmose Ocular/diagnóstico , Toxoplasmose Ocular/tratamento farmacológico , Descolamento Retiniano/diagnóstico , Descolamento Retiniano/tratamento farmacológico , Descolamento Retiniano/etiologia
4.
J Clin Med ; 11(14)2022 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-35887746

RESUMO

The purpose of this study was to evaluate retinal changes in adolescents with childhood-onset, long-lasting type 1 diabetes mellitus (T1D). Patients and healthy controls (HC) underwent optical coherence tomography (OCT) and OCT-angiography (OCTA). Individual macular layers, peripapillary retinal nerve fiber layer (pRNFL), and vascular parameters (vessel area density (VAD), vessel length fraction (VLF) and vessel diameter index (VDI)) of macular superficial vascular (SVP), intermediate (ICP), deep (DCP) and radial peripapillary capillary plexuses (RPCP) were quantified. Thirty-nine patients (5 with (DR group) and 34 without (noDR group) diabetic retinopathy) and 20 HC were enrolled. The pRNFL and ganglion cell layer (GCL) were thicker in noDR compared to HC and DR, reaching statistically significant values versus HC for some sectors. At the macular level, VAD and VLF were reduced in DR versus HC in all plexuses, and versus noDR in SVP (p < 0.005 for all). At the RPCP level, VAD and VDI were increased in noDR versus HC, significantly for VDI (p = 0.0067). Glycemic indices correlated to retinal parameters. In conclusion, in T1D adolescents, retinal capillary and neuronal changes are present after long-lasting disease, even in the absence of clinical DR. These changes modify when clinical retinopathy develops. The precocious identification of specific OCT and OCTA changes may be a hallmark of subsequent overt retinopathy.

5.
Micromachines (Basel) ; 13(3)2022 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-35334654

RESUMO

Electrochemical sensors are powerful tools for the detection and real-time monitoring of a wide variety of analytes. However, the long-term operation of Faradaic sensors in complex media is challenging due to fouling. The protection of the electrode surface during in vivo operation is a key element for improving the monitoring of analytes. Here, we study different EUDRAGIT® controlled release acrylate copolymers for protecting electrode surfaces. The dissolution of these polymers-namely EUDRAGIT® L 30 D-55 and EUDRAGIT® FS 30 D-is triggered by a change in pH of the environment, and it is electrochemically monitored by detecting electrode access by means of a redox probe. The full dissolution of the polymer is achieved within 30 min and the electrode response indicates a complete recovery of the original electrochemical performance. We demonstrate that amperometric sensing is a practical and straightforward technique for real-time and in situ sensing of EUDRAGIT® dissolution profiles. It will find future applications in determining the protection of polymer electrode coating in real matrices and in vivo applications.

7.
ACS Appl Mater Interfaces ; 13(26): 30902-30909, 2021 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-34156234

RESUMO

Molecular surfactants, which are based on a water-insoluble tail and a water-soluble head, are widely employed in many areas, such as surface coatings or for drug delivery, thanks to their capability to form micelles in solution or supramolecular structures at the solid/liquid interface. Electrolyte-gated organic field-effect transistors (EGOFETs) are highly sensitive to changes occurring at their electrolyte/gate electrode and electrolyte/organic semiconductor interfaces, and hence, they have been much explored in biosensing due to their inherent amplification properties. Here, we demonstrate that the EGOFETs and surfactants can provide mutual benefits to each other. EGOFETs can be a simple and complementary tool to study the aggregation behavior of cationic and anionic surfactants at low concentrations on a polarized metal surface. In this way, we have monitored the monolayer formation of cationic and anionic surfactants at the water/electrode interface with p-type and n-type devices, respectively. On the other hand, the operational stability of EGOFETs has been dramatically enhanced, thanks to the formation of a protective layer on top of the organic semiconductor by exposing it to a high concentration of a surfactant solution (above the critical micelle concentration). Stable performances were achieved for more than 10 and 2 h of continuous operation for p-type and n-type devices, respectively. Accordingly, this work points not only that EGOFETs can be applied to a wider range of applications beyond biosensing but also that these devices can effectively improve their long-term stability by simply treating them with a suitable surfactant.

8.
Ther Adv Med Oncol ; 12: 1758835920907543, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32550861

RESUMO

BACKGROUND: The aim of this study was to prospectively analyse, for the first time worldwide by in vivo clinical confocal microscopy (CCM), corneal side effects secondary to the use of epidermal growth factor receptor (EGFR) inhibitor depatuxizumab mafodotin (ABT-414) in a cohort of patients affected by EGFR-amplified recurrent glioblastoma. METHODS: Each enrolled patient underwent full ophthalmologic examination including in vivo CCM of the cornea. Each patient was examined at baseline and every 2 weeks during treatment as long as patient conditions allowed it. RESULTS: A total of 10 patients were consecutively enrolled. Median follow-up was 5 months. No Common Terminology Criteria for Adverse Events Version 4.0 grade 4 toxicity was documented. Two (20%) grade 3 toxicities were documented at week 8. CCM examination detected in all eyes multiple and diffuse hyperreflective white round spots in the corneal basal epithelial layers (100%), progressive subbasal nerve plexus layer fibres fragmentation followed by full disappearance (100%) and appearance of round cystic structures in the corneal epithelium (100%). All CCM documented side effects reached the peak of prevalence and severity after a median of 3 infusions. After treatment discontinuation, the reversibility of corneal side effects was documented at CCM after a median of 4 weeks. CONCLUSION: ABT-414 toxicity is not only directed to the corneal epithelium, but also to corneal nerves. Side effects are detectable in all treated patients and CCM documents early corneal epithelium and subbasal nerve plexus toxicity, with subsequent progressive restoration after treatment discontinuation. Ocular side effects due to ABT-414 can be manageable.

9.
Retina ; 40(7): 1279-1285, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31274711

RESUMO

PURPOSE: To analyze the macular function of eyes with macular-foveal capillaries (MFC), a condition characterized by the absence of the foveal avascular zone (FAZ), identified by optical coherence tomography angiography. METHODS: Eight eyes with MFC at optical coherence tomography angiography and normal visual acuity were consecutively recruited. Eight eyes of healthy subjects were enrolled as healthy controls. All eyes underwent optical coherence tomography, optical coherence tomography angiography, best-correct visual acuity, low-luminance visual acuity, contrast sensitivity measurement, colour vision tests, and both mesopic and scotopic microperimetry. RESULTS: Best-corrected visual acuity, low-luminance visual acuity, contrast sensitivity, and colour vision tests did not differ between the two groups. At mesopic microperimetry, both foveal retinal sensitivity and mean mesopic retinal sensitivity of the central 1° were statistically inferior in MFC versus control eyes (P < 0.0001 and P < 0.0001, respectively). At scotopic microperimetry, a dense foveal scotoma, normally present in control eyes, was completely lacking in MFC eyes. Scotopic foveal retinal sensitivity was statistically superior in MFC versus control eyes (P = 0.009). CONCLUSION: The absence of the foveal dense scotoma in scotopic conditions underlines that the foveal rod-free zone is not present when capillaries are present in this area. An anomalous foveal distribution of photoreceptors, with both rods and cones present in this area, may be postulated in MFC eyes.


Assuntos
Capilares/patologia , Angiofluoresceinografia/métodos , Doenças Retinianas/diagnóstico , Vasos Retinianos/patologia , Tomografia de Coerência Óptica/métodos , Testes de Campo Visual/métodos , Campos Visuais/fisiologia , Adulto , Feminino , Fóvea Central/irrigação sanguínea , Fundo de Olho , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Retinianas/fisiopatologia , Estudos Retrospectivos , Acuidade Visual
10.
Biosens Bioelectron ; 150: 111844, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31740253

RESUMO

Organic electronic materials offer an untapped potential for novel tools for low-invasive electrophysiological recording and stimulation devices. Such materials combine semiconducting properties with tailored surface chemistry, elastic mechanical properties and chemical stability in water. In this work, we investigate solution processed Electrolyte Gated Organic Field Effect Transistors (EGOFETs) based on a small molecule semiconductor. We demonstrate that EGOFETs based on a blend of soluble organic semiconductor 2,8-Difluoro-5,11-bis(triethylsilylethynyl)anthradithiophene (diF-TES-ADT) combined with an insulating polymer show excellent sensitivity and long-term recording under electrophysiological applications. Our devices can stably record the extracellular potential of human pluripotent stem cell derived cardiomyocyte cells (hPSCs-CMs) for several weeks. In addition, cytotoxicity tests of pharmaceutical drugs, such as Norepinephrine and Verapamil was achieved with excellent sensitivity. This work demonstrates that organic transistors based on organic blends are excellent bioelectronics transducer for extracellular electrical recording of excitable cells and tissues thus providing a valid alternative to electrochemical transistors.


Assuntos
Técnicas Biossensoriais , Eletrólitos/isolamento & purificação , Miócitos Cardíacos/metabolismo , Eletrodos , Eletrólitos/química , Fenômenos Eletrofisiológicos , Humanos , Miócitos Cardíacos/química , Polímeros/química , Semicondutores , Transistores Eletrônicos , Água/química
11.
Br J Ophthalmol ; 103(7): 1001-1007, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30127073

RESUMO

PURPOSE: To evaluate, by means of optical coherence tomography (OCT) and OCT angiography (OCTA), early retinal, choroidal and macular perfusion changes induced by a local inflammatory reaction secondary to uncomplicated cataract surgery. METHODS: Selected eyes undergoing cataract surgery were enrolled in a prospective study. OCT and OCTA were performed before cataract surgery (T0) and at day: 1 (T1), 7 (T7), 30 (T30) and 90 (T90). Inner (IR) and outer retinal (OR) volumes, choroidal volume, hyper-reflective retinal spots (HRS) in IR and OR changes were measured at OCT. Macular perfusion was analysed in superficial (SCP), intermediate (ICP) and deep retinal capillary plexuses (DCP). RESULTS: Nine eyes of nine selected patients were consecutively enrolled. Mean IR volume changed after surgery (p=0.0001), increasing progressively from 4.391±0.231 mm³ at T0 to 4.573±0.241 mm³ at T30, p=0.0002. Both mean OR and choroidal volume increased, mainly at T30, but not significantly (p=0.4360 and p=0.2300, respectively). Mean HRS changed during follow-up, increasing at first in IR and later in OR (at T1 and T7, respectively, both p<0.0001). Macular ICP and DCP perfusion increased at T1, whereas macular SCP perfusion did not change. At T90, all OCT and OCTA parameters had almost reached baseline levels. CONCLUSIONS: The increase of HRS at first in IR and later in OR seems to confirm their inflammatory nature. Early OCTA changes (underline) underscore a selective susceptibility of DCP and ICP to a localised inflammatory reaction induced by cataract surgery.


Assuntos
Extração de Catarata , Corioide/patologia , Angiofluoresceinografia/métodos , Inflamação/diagnóstico , Retina/patologia , Tomografia de Coerência Óptica/métodos , Acuidade Visual , Idoso , Estudos Transversais , Feminino , Seguimentos , Fundo de Olho , Humanos , Inflamação/etiologia , Masculino , Período Pós-Operatório , Estudos Prospectivos , Fatores de Tempo
12.
Acta Ophthalmol ; 96(8): e1004-e1009, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30284379

RESUMO

PURPOSE: To evaluate peripapillary retinal nerve fibre layer (RNFL) thickness, measured by spectral-domain optical coherence tomography (SD-OCT), as a surrogate of visual function in a population of paediatric patients affected by optic pathway glioma (OPG) associated with neurofibromatosis type 1 (NF1). METHODS: A total of 38 paediatric patients (66 eyes) affected by MRI-proven OPG were included. Each patient underwent complete ophthalmological examination, including age-appropriate visual acuity (VA) assessment and RNFL analysis by SD-OCT. Visual acuity was classified as normal or pathologic using age-based normative data. Visual acuity was correlated to mean RNFL thickness of the whole peripapillary area and of each single analyzed sector (nasal, superior, temporal, inferior). RESULTS: Visual acuity was normal in 43 (65%) and pathologic in 23 (35%) eyes. Mean parapapillary RNFL thickness of each analyzed sector was significantly lower in eyes with abnormal VA (p < 0.05). The best balanced cut-off value of global RNFL thickness allowing to discriminate between eyes with normal and pathologic VA was 76.25 µm (91%, 76%, 67% and 94% of sensitivity, specificity, positive and negative predicting value, respectively). Considering best balanced cut-off values of other analyzed RNFL sectors, the superior (p = 0.0029) and the inferior (p = 0.0024) sectors reached the higher sensitivity (87% and 87%, respectively) and specificity (81% and 79%, respectively). CONCLUSION: Retinal nerve fibre layer thickness is directly related to VA in children affected by NF1-related OPG, and should be considered as a potential surrogate marker of VA. Retinal nerve fibre layer thickness cut-off values can be used in paediatric patients to discriminate false-positive results obtained by VA measurement.


Assuntos
Fibras Nervosas/patologia , Disco Óptico/patologia , Glioma do Nervo Óptico/diagnóstico por imagem , Células Ganglionares da Retina/patologia , Tomografia de Coerência Óptica/métodos , Acuidade Visual , Adolescente , Criança , Pré-Escolar , Estudos Transversais , Feminino , Seguimentos , Humanos , Masculino , Estudos Prospectivos , Campos Visuais
13.
Br J Ophthalmol ; 102(9): 1238-1243, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29343530

RESUMO

AIMS: To investigate peripapillary vascular changes secondary to radiation optic neuropathy (RON) using optical coherence tomography angiography (OCT-A) and to propose a clinical grading of RON based on OCT-A findings. METHODS: Thirty-four patients affected by RON were consecutively included. Each patient underwent best corrected visual acuity measurement (ETDRS score) and OCT-A (Nidek RS-3000 Advance device, Nidek, Gamagori, Japan). The radial peripapillary capillary plexus (RPCP) and the entire peripapillary capillary bed (EPCB) were analysed. Quantitative analysis of the OCT-A images was performed using open-source available ImageJ software (National Institutes of Health, Bethesda, Maryland, USA). Qualitative analysis based on the proposed clinical grading (Grades 0-4) was also performed by two masked graders. RESULTS: RON clinical (qualitative) classification based on RPCP correlated with the quantitative RPCP perfusion analysis (P=0.0001). RON clinical classification based on RPCP statistically correlated with ETDRS score (P=0.001). RON clinical classification based on EPCB also correlated with the quantitative EPCB perfusion analysis and ETDRS score (P=0.02 and P=0.01, respectively). Compared with the clinical classification based on EPCB, the qualitative classification based on RPCP reached a higher intergrader agreement (0.96 and 0.86, respectively). CONCLUSION: OCT-A can be used to detect RPCP abnormalities and to clinically classify RON with a high interexaminer agreement. The proposed clinical classification is supported by the quantitative analysis based on the use of specific images elaboration techniques and correlates with visual acuity of the examined eyes.


Assuntos
Angiofluoresceinografia/métodos , Disco Óptico/patologia , Doenças do Nervo Óptico/diagnóstico , Lesões por Radiação/diagnóstico , Vasos Retinianos/patologia , Tomografia de Coerência Óptica/métodos , Acuidade Visual , Feminino , Seguimentos , Fundo de Olho , Humanos , Masculino , Pessoa de Meia-Idade , Disco Óptico/efeitos da radiação , Doenças do Nervo Óptico/etiologia , Estudos Prospectivos , Lesões por Radiação/complicações , Índice de Gravidade de Doença , Fatores de Tempo
14.
Retina ; 38(3): 585-593, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28248826

RESUMO

PURPOSE: To evaluate the prevalence, the vascular features, and the clinical diagnostic implication of retinal vascular abnormalities (RVAs) associated with neurofibromatosis Type 1 (NF1) in a large cohort of patients. METHODS: Two hundred and ninety-four patients affected by NF1 were consecutively enrolled. The presence of RVAs was detected by means of infrared confocal scanning laser ophthalmoscopy images. Three hundred age- and race-matched healthy subjects were enrolled as a healthy control group. Fluorescein angiography, indocyanine green angiography, and optical coherence tomography angiography were also performed in patients with RVAs. RESULTS: Retinal vascular abnormalities were detected in 18 patients with NF1 (6.1%) and in none of the healthy subjects. Retinal vascular abnormalities appeared in all cases as well-defined, small, tortuous retinal vessels with a spiral aspect, originating from small tributaries of retinal veins. The presence of RVAs did not correlate with the presence of other specific ocular or systemic NF1 features (P > 0.05). On optical coherence tomography angiography, RVAs appeared as an isolated tortuous vessel of the superficial vascular plexus in all cases, associated with localized anomalous crowded and congested capillary network of the deep vascular plexus in 75% of cases. CONCLUSION: Retinal vascular abnormalities are present in a limited proportion of patients affected by NF1 and can be considered an additional distinctive sign of the disease.


Assuntos
Neurofibromatose 1/patologia , Doenças Retinianas/patologia , Vasos Retinianos/patologia , Adolescente , Adulto , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Angiofluoresceinografia , Humanos , Masculino , Microscopia Confocal , Neurofibromatose 1/diagnóstico , Oftalmoscopia , Prevalência , Estudos Prospectivos , Doenças Retinianas/epidemiologia , Tomografia de Coerência Óptica/métodos , Adulto Jovem
15.
RSC Adv ; 8(48): 27509-27515, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-30713682

RESUMO

Understanding the physics behind the operational mechanism of Electrolyte-Gated Organic Field-Effect Transistors (EGOFETs) is of paramount importance for the correct interpretation of the device response. Here, we report the systematic functionalization of the gate electrode of an EGOFET with self-assembled monolayers with a variety of dipolar moments showing that both the chemical nature and the monolayer density influence the electrical characteristics of the device.

16.
Ophthalmol Retina ; 2(8): 827-835, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-31047537

RESUMO

PURPOSE: To investigate the pathophysiologic interrelations between retinal neural and vascular changes, detected by spectral-domain OCT (SD-OCT) and OCT angiography (OCTA), resulting from optic nerve axonal degeneration. DESIGN: Institutional, observational, case-control study with prospective enrollment. PARTICIPANTS: Twenty-six patients affected by optic nerve axonal degeneration secondary to posterior optic pathway glioma (OPG) involving the chiasma, the postchiasmatic visual pathway, or both (but not involving optic nerves) and 24 gender- and age-matched healthy participants were included consecutively. METHODS: Best-corrected visual acuity (Early Treatment Diabetic Retinopathy Study score) was measured and SD-OCT (Heidelberg Engineering, Heidelberg, Germany) and OCTA (Nidek RS-3000 Advance device; Nidek, Gamagori, Japan) were performed. MAIN OUTCOME MEASURES: Peripapillary retinal nerve fiber layer (pRNFL), macular ganglion cell complex (GCC), and inner nuclear layer (INL) were analyzed using SD-OCT. The radial peripapillary capillary plexus, full-thickness peripapillary retina vascularization, and the macular superficial plexus (SCP) and deep capillary plexus (DCP) were analyzed using OCTA. RESULTS: Peripapillary retinal nerve fiber layer and GCC thickness were reduced in eyes affected by OPG (P < 0.0001). Radial peripapillary capillary plexus perfusion also was reduced, as well as full-thickness peripapillary retina vascularization (P < 0.01 and P < 0.05, respectively). Macular DCP perfusion was reduced in eyes affected by OPG, whereas macular SCP perfusion did not differ between the 2 groups (P < 0.05 and P > 0.05, respectively). Global pRNFL thickness reduction correlated with the reduction of peripapillary perfusion (P < 0.01). Macular GCC thickness reduction did not correlate with SCP reduction (P > 0.05). The reduction of macular DCP perfusion did not correlate with inner nuclear layer thickness (P > 0.05). CONCLUSIONS: Retinal neural remodeling secondary to optic nerve axonal degeneration resulting from OPG located at or posterior to the chiasm is accompanied by a secondary retinal vascular remodeling involving not only the peripapillary area, but also the macular area (DCP).

17.
Chem Soc Rev ; 46(1): 40-71, 2017 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-27722675

RESUMO

Self-assembly is possibly the most effective and versatile strategy for surface functionalization. Self-assembled monolayers (SAMs) can be formed on (semi-)conductor and dielectric surfaces, and have been used in a variety of technological applications. This work aims to review the strategy behind the design and use of self-assembled monolayers in organic electronics, discuss the mechanism of interaction of SAMs in a microscopic device, and highlight the applications emerging from the integration of SAMs in an organic device. The possibility of performing surface chemistry tailoring with SAMs constitutes a versatile approach towards the tuning of the electronic and morphological properties of the interfaces relevant to the response of an organic electronic device. Functionalisation with SAMs is important not only for imparting stability to the device or enhancing its performance, as sought at the early stages of development of this field. SAM-functionalised organic devices give rise to completely new types of behavior that open unprecedented applications, such as ultra-sensitive label-free biosensors and SAM/organic transistors that can be used as robust experimental gauges for studying charge tunneling across SAMs.

18.
Sci Rep ; 6: 39623, 2016 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-28004824

RESUMO

Since the first demonstration, the electrolyte-gated organic field-effect transistors (EGOFETs) have immediately gained much attention for the development of cutting-edge technology and they are expected to have a strong impact in the field of (bio-)sensors. However EGOFETs directly expose their active material towards the aqueous media, hence a limited library of organic semiconductors is actually suitable. By using two mostly unexplored strategies in EGOFETs such as blended materials together with a printing technique, we have successfully widened this library. Our benchmarks were 6,13-bis(triisopropylsilylethynyl)pentacene and 2,8-difluoro-5,11-bis(triethylsilylethynyl)anthradithiophene (diF-TES-ADT), which have been firstly blended with polystyrene and secondly deposited by means of the bar-assisted meniscus shearing (BAMS) technique. Our approach yielded thin films (i.e. no thicker than 30 nm) suitable for organic electronics and stable in liquid environment. Up to date, these EGOFETs show unprecedented performances. Furthermore, an extremely harsh environment, like NaCl 1M, has been used in order to test the limit of operability of these electronic devices. Albeit an electrical worsening is observed, our devices can operate under different electrical stresses within the time frame of hours up to a week. In conclusion, our approach turns out to be a powerful tool for the EGOFET manufacturing.


Assuntos
Amplificadores Eletrônicos , Técnicas Biossensoriais , Naftacenos/química , Poliestirenos/química , Desenho de Equipamento , Microscopia , Microscopia de Força Atômica , Compostos Orgânicos/química , Potenciometria , Semicondutores , Transistores Eletrônicos , Água
19.
Adv Mater ; 28(46): 10311-10316, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27723255

RESUMO

This communication presents a novel electrolyte gated field-effect transistor based on a blend of dibenzo-tetrathiafulvalene and polystyrene deposited through bar-assisted meniscus shearing. This technique allows the fabrication of high performing electronic devices suitable for (bio)sensing applications and might capture industrial interest due to its scalability. The reported devices can operate in aqueous solution with comparable complexity to real samples.

20.
ACS Nano ; 10(7): 7125-34, 2016 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-27299370

RESUMO

We describe a fast and versatile method to functionalize high-quality graphene with organic molecules by exploiting the synergistic effect of supramolecular and covalent chemistry. With this goal, we designed and synthesized molecules comprising a long aliphatic chain and an aryl diazonium salt. Thanks to the long chain, these molecules physisorb from solution onto CVD graphene or bulk graphite, self-assembling in an ordered monolayer. The sample is successively transferred into an aqueous electrolyte, to block any reorganization or desorption of the monolayer. An electrochemical impulse is used to transform the diazonium group into a radical capable of grafting covalently to the substrate and transforming the physisorption into a covalent chemisorption. During covalent grafting in water, the molecules retain the ordered packing formed upon self-assembly. Our two-step approach is characterized by the independent control over the processes of immobilization of molecules on the substrate and their covalent tethering, enabling fast (t < 10 s) covalent functionalization of graphene. This strategy is highly versatile and works with many carbon-based materials including graphene deposited on silicon, plastic, and quartz as well as highly oriented pyrolytic graphite.

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