BIOSENSORS

During the last decade we have developed various lab-on-a-chip systems containing integrated electroanalytical (AMP, ECIS), magnetic (GMR) and optical (OPD, Oxygen Sensor) detection methods to continuously monitor cell viability, morphology changes and cellular activities, such as cell-to-cell interactions, respiration and extra cellular matrix (ECM) production, as well as the rate of NP uptake. We have recently introduced contactless impedance spectroscopy as a powerful biosensing technology and employed to assess a variety of microbial cells, viruses, lipid vesicles and human cells.


ELECTROANALYTICAL BIOSENSORS

  • IMPEDANCE SPECTROSCOPY
A well-established label-free analysis method is impedance spectroscopy, which provides a powerful tool for cell monitoring  including cell spreading and toxicity studies, monitoring of cell junctions and barrier function, endothelial cell stimulation and mast cell activation,as well as stem cell differentiation.We have developed a novel lab-on-a-chip system for continuous and non-invasive monitoring of microfluidic cell cultures to reliably and reproducibly detect cell-substrate interactions, cell viability and intracellular conductivity changes.




UPDATE - CONTACTLESS IMPEDANCE BIOSENSORS

The recent trend towards improved, reliable and more biologically relevant assays has provided new opportunities for label-free technologies where time-resolved measurements are implemented to quantify the phenotypic changes of cells. To study differentiation kinetics of stem cells at implant surfaces, we have electrically insulated (passivated)  µIDES using nanolayers of titanium oxide using conduct high-frequency contactless impedance spectroscopy.




  • AMPEROMETRIC MICROSENSORS 
We have developed a lab-on-a-chip containing embedded amperometric sensors in four microreactors that can be addressed individually to provide the continuous, stable, reliable and accurate detection of blood glucose. The electrochemical detection of blood glucose variations in the absence of electrode fouling events is realized by integrating crystalline surface layer proteins (S-layer) that function as an efficient antifouling coating, a highly-oriented immobilization matrix for biomolecules and an effective molecular sieve with pore sizes of 4 to 9 nm.


OPTICAL BIOSENSORS

  • ORGANIC PHOTO DETECTORS
Nanotechnology provides the tools to develop novel biosensors with improved performance, including sensitivity and response time that can be readily integrated into diagnostic devices. Solution-processed fully spray-coated organic photodiods (OPDs) have recently emerged as powerful and versatile photodetectors that can be easily integrated with microfluidics showing far less design constraints in comparison to existing solid-state photodetectors. The main advantages of integrating OPDs include uncomplicated optical alignment, thin device architecture (<1 µm), precise control over the shape of the active area (ranging from µm² to cm²) and substrate independence. 

OPD



  • FLUORESCENCE OXYGEN SENSING  
Oxygen concentration is an immensely important factor in cellular studies that may effect important physiological processes including tumor biology and vascularization, hypoxia-reperfusion phenomena, tissue engineering and stem cell differentiation. We have jointly developed in collaboration with Prof. Torsten Mayr (Institute of Analytical Chemsitry and Food Chemistry, TU Graz) a setup comprising of a fabrication process of microfluidic chips with integrated luminescent sensing films combined with referenced oxygen imaging applying a color CCD-camera.





  • OPTICAL MICROSCOPY IMAGING  
An important aspect in the development of in vitro models is concerned with tissue functionality that is dependent on how well the in vitro model reproduces the key physiological and biological characteristics of its in vivo archetype. A variety of immunohistochemistry methods and life-staining procedures are developed in our labs using standard optical microscopy imaging to detect specific cellular phenotpyes.

MAGNETIC BIOSENSORS

  • GIANT-MAGNETORESISTIVE MIRCOSENSORS  
The AIT MAGLab platform was developed by Dr. Jörg Schotter (AIT) and combines magnetoresistive 
sensors, magnetic particles and microfluidics. 
The basic principle of our approach is to monitor the signal induced by superparamagnetic particles (beads) in embedded magnetoresistive sensors, which changes when the particles are phagocytosed by cells.