Concurso com inscrição aberta.
QUÍMICA INORGÂNICA (de 07/01 a 20/05/2016)
Programa de Seminários do IQ - Abril
27/abril – quarta-feira
Mini-auditório do IQ
“Ion-Selective Optodes Based on Reversible Metastable-State Photoacids”
Prof. Dr. Karin Y. Chumbimuni Torres, University of Central Florida, Orlando
Abstract: An entirely new approach in activatable and controllable sensing using visible light or near-infrared (NIR) based on metastable photoacids (mPAHs) is presented, which could broaden and significantly enhance the current biological, biomedical and environmental applications. Most of the activatable and controllable platforms for sensing require ultraviolet (UV) irradiation, which promotes cellular damage, limiting sensing in biological and biomedical applications. Additional limitations are irreversibility and photo-fatigue of the sensor, which is inherent to the systems that use UV-irradiation for activation. These limitations could be overcome by using mPAHs that do not require UV irradiation. A carbanion mPAH, is reported which generates a large photo induced proton concentration under visible light and is compatible with organic media, due to its high lipophilicity. This carbanion mPAH displays two peaks at each absorption spectra before and after activation which correspond to carbanion mPAH protonated and deprotonated, which allows for ratiometric measurements. The carbanion mPAH is used in an activatable system (turnedON/OFF) when introduced into ion sensing bulk membranes, and more than ten reproducible cycles was performed and no photo-fatigue was observed. This ion sensing membrane was also exposed to increasing concentrations of calcium ions before activation. No change in absorbance was observed, indicating that the ion-exchange process does not occur as a result of the absence of protons. After activation with visible light, the ion sensing membrane showed a change in the absorbance at different concentrations of Ca2+ in the range of 1.0 x 10-7 to 1.0 x 10-1 M in formate buffer.
Docente responsável: Lauro Tatsuo Kubota.
Café com Química
27/abril - quarta-feira
"A sexualidade antiga e moderna"
Intermediador: Prof. Pedro Paulo A. Funari, IFCH
A sexualidade foi encarada, a partir da modernidade, em particular desde o século XIX, como algo natural, até mesmo biológico e pré-destinado. As interpretações médicas contribuíram para essa suposta naturalização. Por isso mesmo, uma perspectiva história e antropológica permite uma visão mais nuançada do tema e a Antiguidade serve muito bem para isso. Na Antiguidade, a sexualidade não definia as pessoas e não havia, portanto, conceitos como heterossexualidade e homossexualidade, invenções do século XIX. As práticas sexuais, além de não serem definidoras, marcavam-se por um continuum, bem representada por uma divindade como Hermafrodita. A literatura antiga mostra bem essa situação, assim como, tanto mais, as evidências arqueológicas e iconográficas. Foi na modernidade que se inventou uma sexualidade normativa, fundada em um leitura médica muito limitada, que opunha a virilidade forte e racional à feminilidade fraca e emotiva. A antiguidade serve, portanto, para relativizar as naturalizações modernas.
Sobre o tema, confira-se o capítulo de Rago e Funari, disponível em:
28/abril - quinta-feira
Mini-auditório do IQ
Prof. Arben Merkoçi, ICREA & Catalan Institute of Nanoscience and Nanotechnology (ICN2), Bellaterra (Barcelona), Catalonia, Spain
Abstract: Development of novel diagnostic tools with interest for point of care applications represents one of the main research fields for the nanobiotechnology. Efforts are shown to either develop brand new devices or improve existing ones thanks to the use of nanomaterials and nanotechnologies. Between the various devices biosensing systems based on electrical or optical transducing schemes are overall in the focus of interest given the simplicity and cost efficiency of detection. Among the various biosensing system performance requirements the high sensitivity and selectivity of the response are crucial for applications in clinical diagnostics. The fulfilment of such requirements means the detection of low levels of clinical biomarkers in human fluids. Given the fact that biomarkers are present in very low concentrations the need for biosensing systems that can detect these analytes with high sensitivity and selectivity that include very low detection limits along with high reproducibility is an important challenge. To overcome the difficulties in accomplishing all these requirements the main efforts are driven toward signal amplification and noise reduction of biosensing systems by the incorporation of nanomaterials. Nanomaterials (NMs) such as carbon nanotubes, graphene, metallic nanoparticles, nanowires and quantum dots are showing to be excellent materials to be used as electrochemical transducers or labels in DNA (or genosensors) sensors beside enzymatic sensors, immunosensors, or cell sensors. The amplification of the detection of biorecognition events (ex. DNA hybridization, immunoreactions etc) are the most important objectives of the current bioanalytical chemistry. In this context integration of the catalytic properties of some biomolecules with those of nanomaterials is appearing to be a promising way to enhance the sensitivity of the bioassays. Examples related to various clinical biomarkers as well as contaminants detection will be shown. The developed devices and strategies are intended to be of low cost while offering high analytical performance in screening scenarios beside other applications. Special emphasis will be given to lab-on-a-chip platforms with integrated electrochemical detection with interest for various applications. In addition simple paper-based platforms that operate in lateral flow formats with interest for various detections also will be shown.
Docente responsável: Lauro Kubota