Dr Cesar Fernandez-Sanchez (Barcelona Institute for Microelectronics: CNM-IMB)
Location: Stephenson Building, room F16 (first floor)
Time/Date: 16th February 2012, 16:00 - 17:00
The development of biosensor approaches in life sciences has concentrated the efforts of many researchers across the world for the last two decades. In spite of the vast range of reported configurations and applications, just a few of them have found niche applications in the marketplace. The most successful biosensor device is undoubtedly the portable enzyme-based electrochemical sensor for glucose, daily used by diabetes patients all over the world. Electrochemical techniques have played a key role in the development of biosensors owing to the simple and cost-effective compact instrumentation that they required as well as the high sensitivity and selectivity towards the detection of a great variety of target analytes that they exhibit. Among them, impedance spectroscopy (IS) has emerged as a powerful analytical tool for investigating the mechanisms of electrochemical reactions, measuring the dielectric and charge transport properties of materials, and, more recently, for characterising and assessing the performance of biosensor approaches. In the biosensor field, the impedance magnitude is understood as the ratio between an alternating voltage of small amplitude applied to a system and the resulting alternating current measured. When these measurements are carried out over a wide frequency range, the resulting impedance can be plotted in the form of spectra containing a great deal of information about the electrical behaviour of the biosensor device under study. Such electrical behaviour is often modelled with an equivalent circuit formed by discrete components, namely resistors and capacitors. By measuring the values of these components it is possible to make a thorough evaluation of the performance of the sensor device and quantify its response to the concentration of a target analyte. In this talk, I will give an overview of this technique and its importance in the field of biosensors, followed by a presentation of impedimetric sensor approaches I have worked on for the detection of biomarkers and microorganisms based on different detection schemes including the development of an impedance-based readout system for protein and DNA microarrays.
Dr César Fernández-Sánchez holds a BSc in Analytical Chemistry (1993) and a PhD in Chemistry (1999), both from the University of Oviedo (Spain). From 2001 to 2003, he worked as a Postdoctoral researcher at the Newcastle University under the supervision of Prof Calum McNeil, with whom he started his work on impedance-based biosensors. During his stay at Newcastle, he was awarded an individual Marie Curie Fellowship of the EU 5th Framework programme. In 2004, he moved to Barcelona and joined the Chemical Transducers Group at the department of Micro-/Nanosystems of the Institute for Microelectronics (IMB-CNM (CSIC)), as a tenure-track Ramon y Cajal researcher. Since 2009, he holds a permanent position as a senior researcher at IMB-CNM. His research activity is focused on the development of chemical sensor generic platforms integrating miniaturized electrical transducers, based on either impedimetric or voltammetric transduction modes, and affinity bioreagents or biomimetic receptors as recognition elements. In addition, he actively works on the application of nanomaterials and the micro-/nanopatterning of organic-inorganic polymeric materials for the development of disposable chemical sensors. He has co-authored over fifty peer-reviewed articles and presented more than sixty communications in national and international conferences.
Published: 18th January 2012