The main objective of the GTQ is the development of analytical microsystems including lab on chips (LoC), based on different transduction modes together with non-conventional fluidic management approaches. Electrochemical, optical/photonic and multiparametric sensor devices are included, by monolithic or hybrid integration, together with the required fluidic components depending on the analytical application of the final system.
In this context, the group main activities are focused on the development of:
1. Electrochemical transducers. Ion-field effect transistors (ISFETs for measuring pH and ions), interdigitated electrodes (IDEs) for conductivity and electrical permittivity measurements, as well as metal thin-film electrodes (Au and Pt) for voltammetric analysis, are developed. The latter are being applied in the development of enzymatic and affinity-based biosensors with the signal being sometimes enhanced by surface modification with nanomaterials such as carbon nanotubes and metal nanoparticles.
2. Photonic transducers. Herein, different optical elements such as lenses, filters, emitters and waveguides are included, with which versatile photonic devices are being developed and show the ability to record spectral response, scattering and phase modulation analytical signals.
3. LoC integration technologies. Different strategies and architectures for the monolithic and/or hybrid integration of chemical transducers with fluidic elements, both active and passive, are developed. Silicon technologies are being applied together with microfabrication processes such as micromolding, soft lithography, micromilling as well as a variety of materials including polydimethylsiloxane (PDMS), SU8, hybrid xerogels, polymethylmethacrylate (PMMA), polycarbonate (PC) and wax.
The developed microsystems are meant to be used for the complete automation of analytical processes (sampling, analysis and data processing) using very low sample and reagent volumes. Those so far developed include the following:
1. LoCs based on PMMA cells for multiparametric analysis of human consumption water and wines, integrating electrochemical sensors for measuring pH, ions, heavy metals, electrochemical oxygen demand and chlorine, as well as optical sensors of spectral response.
2. LoCs that make use of optofluidic approaches fabricated in PDMS and include optical filters, light waveguiding structures, emitters, microreactors and microchannels. These are being used for cell counting and the measurement of lactate or heavy metals.
3. LoCs that integrate silicon chips and polymeric microfluidic structures assembled on printed circuit boards. These are being used as autonomous systems for the measurement of parameters in cell cultures (pH, cell population and enzymatic activity).
4. LoCs based on electrochemical transducer arrays for the readout of DNA and protein bioarrays for biomedical or environmental applications.
Most of the mentioned microsystem approaches are fabricated by well standardized technologies. In this context, we put a great deal of effort into transferring these technologies and demonstrate the potential of the developed systems for giving solutions to analytical necessities in the environmental and biomedical fields as well as in monitoring different production processes and assessing the quality of the final products.