Fabrication of 2D colloidal crystals over large areas for biosensing

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Física Aplicada. Fecha de lectura: 23-06-2017Los dispositivos basados en la Resonancia de Plasmón Superficial se aplican extensamente como biosensores para identificar distintas biomoléculas de manera sensible, rápida, en tiempo real, libre de marcadores y/o con la posibilidad de multidetección. Actualmente, los desafíos al desarrollo de este tipo de dispositivos se encuentran en los altos costes de la instrumentación empleada, la limitada capacidad de conectar otras técnicas analíticas y una carencia de sensibilidad cuando se aplican a la detección de analitos muy diluidos o con pequeño peso molecular. Con el fin de vencer estos desafíos, se ha dirigido una extensa investigación al desarrollo de plataformas SPR avanzadas, basadas en materiales innovadores y métodos de fabricación que permiten una producción económica y masiva de grandes superficies nanoestructuradas, así como de dispositivos miniaturizados y de bajo coste. En este trabajo de tesis se ha llevado a cabo la optimización de un proceso para la producción de superficies plasmónicas sobre grandes áreas. La técnica de nanofabricación propuesta combina litografía coloidal y procesos plasma. En particular, hemos estudiado en detalle la formación de monocapas coloidales según el método Langmuir-Blodgett, sirviendo de máscaras para crear nanoestructuras en sustratos sólidos. El proceso implica un ataque plasma, la deposición de oro y la eliminación del residuo coloidal para obtener una superficie que consiste en cristales plasmónicos bidimensionales. Ajustando los parámetros del proceso es posible diseñar estructuras en materiales diferentes, controlando con precisión la relación de aspecto de la estructura final y, por consiguiente, la posición espectral de la respuesta óptica de acuerdo con el sistema de adquisición apropiado. La versatilidad de este método de fabricación ofrece gran potencial para un eficiente, fácil y masivo desarrollo de cavidades de oro con forma, diámetro y periodicidad controlables. Finalmente, se ha demostrado que estas superficies trabajan como plataformas eficaces en experimentos de SPR y SERS para una detección rápida, de tiempo real y sensible de distintos analitos protéicos (como la proteína pentraxin PTX3) y genómicos (como el gen del tumor de Wilms).Surface plasmon resonance (SPR)-devices are widely applied as biosensing platfoms to perform a potentially sensitive, rapid, real time, label free and/or multiplexed detection. As a drawback, this technology is often challenged by high instrumentation costs, poor interfacing capabilities with other analytical techniques and a lack of sensitivity when applied to direct detection of highly diluted targets or analytes of small molecular weight. In order to overcome these challenges, an extensive research has addressed the development of advanced SPR platforms based on innovative nanomaterials and fabrication methods, enabling a low cost and massive production of large area nanostructured surfaces, as well as affordable miniaturized detection devices. In this thesis we report the optimization of a protocol for the production of large area plasmonic surfaces. The proposed nanofabrication technique combines colloidal lithography and plasma processes. In particular, we deeply studied the Langmuir-Blodgett formation of colloidal monolayers, acting as efficient etching masks when transferred on solid substrates. The sequential etching process, gold deposition and particle lift off allowed obtaining a surface made of 2D plasmonic crystals. By adjusting the process parameters it is possible to nanostructure different materials, leading to a fine tuning of the final structure aspect ratio and, consequently, of the spectral position of the optical response according to a proper acquisition setup. The versatility of this fabrication method shows great potential for easy and massive parallel fabrication of gold cavity arrays with a tailorable shape, diameter and periodicity. These surfaces have been proved to work as sensitive platforms in SPR and SERS experiments for a fast, real time and multiplexing detection of proteomic (long pentraxin PTX3) and genomic (Wilms tumor gene) biomarkers

Organic Light-Emitting Transistors in a Smart-Integrated System for Plasmonic-Based Sensing

AbstractThe smart integration of multiple devices in a single functional unit is boosting the advent of compact optical sensors for on‐site analysis. Nevertheless, the development of miniaturized and cost‐effective plasmonic sensors is hampered by the strict angular constraints of the detection scheme, which are fulfilled through bulky optical components. Here, an ultracompact system for plasmonic‐sensing is demonstrated by the smart integration of an organic light‐emitting transistor (OLET), an organic photodiode (OPD), and a nanostructured plasmonic grating (NPG). The potential of OLETs, as planar multielectrode devices with inherent micrometer‐wide emission areas, offers the pioneer incorporation of an OPD onto the source electrode to obtain a monolithic photonic module endowed with light‐emitting and light‐detection characteristics at unprecedented lateral proximity of them. This approach enables the exploitation of the angle‐dependent sensing of the NPG in a miniaturized system based on low‐cost components, in which a reflective detection is enabled by the elegant fabrication of the NPG onto the encapsulation glass of the photonic module. The most effective layout of integration is unraveled by an advanced simulation tool, which allows obtaining an optics‐less plasmonic system able to perform a quantitative detection up to 10−2 RIU at a sensor size as low as 0.1 cm3

Hereditary trichilemmal cysts: a proposal for the assessment of diagnostic clinical criteria

Trichilemmal cysts (TCs) can occur as sporadic lesions or in hereditary-familial settings with autosomal dominant transmission. These entities have not been widely analyzed in their peculiar aspects yet. The aim of this study was to describe a cohort of patients with diagnosis of TCs through a clinical and biomolecular characterization, intended to highlight some effective diagnostic criteria for their identification. Among 149 cases of this study, 24 cases of TCs (16.1%) arose in patients with at least one first-degree relative with diagnosis of TCs. Peculiar findings concerning hereditary lesions included the multiple presentation with an early onset age. On the basis of clinical evaluation, we propose a panel of clinical and histologic criteria for the diagnosis of hereditary TCs, which includes: (i) the diagnosis of TCs in at least two first-degree relatives or in three first- or second-degree relatives in two consecutive generations; (ii) at least one of the patients with TCs diagnosed <45 years; and (iii) the diagnosis of multiple or giant (>5-cm lesions) or rare histopathologic features (proliferating and ossifying) TCs

BRAFp.V600E, p.V600K, and p.V600R Mutations in Malignant Melanoma: Do They Also Differ in Immunohistochemical Assessment and Clinical Features?

Although the detection of BRAF p.V600E mutation by immunohistochemistry was clearly described in melanoma, discordant evidences were reported for the detection of p.V600K and p.V600R mutations. The aim of the study was to evaluate the efficacy of BRAFp.V600E, p.V600K, and p.V600R detection by immunohistochemistry in melanoma

Sphenoid asymmetry associated to other skeletal anomalies in a clear cut case of PTCH1 mutated Gorlin-Goltz syndrome: a novel finding?

Gorlin-Goltz syndrome is an autosomal dominantly inherited disorder linked to PTCH1 mutation, recognized by a collection of clinical and radiologic signs (macrocephaly, frontal bossing, multiple intracranial calcifications including falx cerebri and atlanto-occipital ligament). We describe here a the case of a family with clear cut criteria for Gorlin-Goltz syndrome presenting the association of cranio-facial and skeletal anomalies together with a peculiar sphenoid variant. Two patients, father and son, were examined because of multiple basal cell carcinomas and keratocystic odontogenic tumours. Other suggestive findings were multiple positive family history, typical skeletal anomalies and a novel PTCH1 germline mutation (c.1041delAA). Craniofacial and other skeletal anomalies displayed at 3D and helical CT scan were: macrocephaly, skull base asymmetry (positional plagiocephaly), mandibular prognathism, mandibular condylar deformation with hyperplasia of the coronoid process, bifidity of multiple ribs and giant multilocular odontogenic jaw cysts. Extensive multilamellar calcifications were found in falx cerebri, tentorium, falx cerebelli and in the apical segment of the atlanto-occipital ligament. Thoracic anomalies included bifid left 3rd, 4th, 5th and 6th rib, dismorphic body of the 3rd thoracic vertebra, dorsolumbar scoliosis, sacrum acutum. Interestingly, 3D-CT scan showed asymmetry of both sphenoid wings with thickening of the left wing sphenoid wing together with irregularity of the architecture of trabecular bone with alternating osteolytic and sclerotic areas. Abnormalities of the sphenoid bone are not very common, and consist of differently aggressive entities: some of them are typical of the pediatric age in few hereditary and congenital disorders. The application of new criteria (i.e. peculiar calcifications of ligaments and sphenoid asymmetry) to a wider case series can lead to the early diagnosis of Gorlin syndrome, especially in pediatric patients, when the full phenotype is not yet expressed. The inclusion of bifid ribs as a novel major criteria and the recognition of peculiar cranial anomalies such as sphenoid asymmetry, well detected at volume CT reconstruction, might be useful for the recognition and characterization of misdiagnosed cases

Plasmonic Structures for Sensing and Emitting Devices

We report on the study of a plasmonic nanostructure that could be adopted as platform for emitting and sensing applications. Several devices have been prepared and characterized by atomic force microscopy (AFM) and Fourier transform micro-reflectance (FT- pR) techniques. In addition, a modelling via finite-difference time-domain (FDTD) simulations have been developed in order to interpret the morphological shape and the optical response of the considered structures. Until now, remarkable performances as surface plasmon resonance (SPR) based optical sensor have been founded. Moreover, we are performing preliminary trials in order to establish a coupling between photoluminescence (PL) features of suitable emitters with respect to the plasmonic resonances

The Multidisciplinary Management of Cutaneous Squamous Cell Carcinoma: A Comprehensive Review and Clinical Recommendations by a Panel of Experts

Simple Summary Cutaneous squamous cell carcinoma is one of the most common forms of cancer. Although most cases are cured with surgical excision, a few tumors are associated with a high risk of local or distant relapse; therefore, it is relevant to identify high-risk lesions among all other low-risk CSCCs for the proper diagnostic and therapeutic management. Chemotherapy achieves mostly short-lived responses that do not lead to a curative effect and are associated with severe toxicities. Recently, PD-1 inhibitor cemiplimab was approved by the regulatory authorities for the treatment of advanced cutaneous squamous cell carcinoma; subsequently, the anti-PD-1 agent pembrolizumab received the approval by the FDA only in the same setting. Here, we provide a literature review and clinical recommendations by a panel of experts regarding the diagnosis, treatment, and follow-up of cutaneous squamous cell carcinoma. Cutaneous squamous cell carcinomas (CSCC) account for about 20% of all keratinocyte carcinomas, which are the most common form of cancer. Heterogeneity of treatments and low mortality are a challenge in obtaining accurate incidence data and consistent registration in cancer registries. Indeed, CSCC mostly presents as an indolent, low-risk lesion, with five-year cure rates greater than 90% after surgical excision, and only few tumors are associated with a high-risk of local or distant relapse; therefore, it is particularly relevant to identify high-risk lesions among all other low-risk CSCCs for the proper diagnostic and therapeutic management. Chemotherapy achieves mostly short-lived responses that do not lead to a curative effect and are associated with severe toxicities. Due to an etiopathogenesis largely relying on chronic UV radiation exposure, CSCC is among the tumors with the highest rate of somatic mutations, which are associated with increased response rates to immunotherapy. Thanks to such strong pre-clinical rationale, clinical trials led to the approval of anti-PD-1 cemiplimab by the FDA (Food and Drug Administration) and EMA (European Medicines Agency), and anti-PD-1 pembrolizumab by the FDA only. Here, we provide a literature review and clinical recommendations by a panel of experts regarding the diagnosis, treatment, and follow-up of CSCC

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Field Enhancement by Shaping Nanocavities in a Gold Film

The paper reports on 2D plasmonic crystals composed of a hexagonal lattice of polymeric nanopillars embedded in an optically thick gold film on a glass substrate. A tapered shape of the polymeric pillars is proved to localize the elec- tric field distribution close to the free surface of the device and to determine a significant increase in the electric field intensity particularly when the incident light comes from the glass side. These effects significantly improve the sample sensitivity to a refractive index change occurring at the free surface of the device