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Biosensor Development

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					   Biosensor Development
Aptasensor for a small organic
       molecule, TCA
                   Peter Pfeiffer
   Bioengineering and Bioelectrochemistry Group
             University Rovira i Virgili
              Tarragona, 02.03.2005

          Supervisor: Dr. Ioanis Katakis
Facing the Problem

              Low odour threshold (8-20 ppt)
              Abundance of other compounds




             Arising from the nature of the
             problem the sensor has to be
             sensitive
             easy to use
             cheap!
          Components of Biosensors
Biosensors are
devices that use
biological reactions
for detecting target
analytes. They
couple a biological
recognition element
(interacting with the
target analyte)
with a physical
transducer that
translates the
biorecognition event
into a useful
electrical signal.
            Antibodies-Aptamers
                         Antibodies and aptamers can bind the
                         relative target with high affinity and
                         specificity. However, aptamers offer
                         advantages that make them very promising
                         in analytical and diagnostic applications.




•   Avoiding animal systems
•   Can be functionalised
•   No batch to batch differences
•   Higher stability
•   Higher affinity/selectivity
                       My work
                                 Detection methods

                                 Fluorescent intensity,
                                 quenching, anisotropy
                                 Colorimetric
                                 Quartz Crystal Microbalance
                                 Atomic Force Microscope-
                                 cantilever
                                 Surface Plasmon Resonance
                                 Molecular beacons
New, simple electrochemical
detection method:                Enzyme Linked Immunoassay
Impedance Spectroscopy

                                    Need of added agents
                              Detection limit in the μM-nM range
Impedance Spectroscopy
     Double layer
                                   Potential



                                     Bulk




                Diff.

          C
                                 R



         RCT            Warburg element
       What problems I shall face
                                 Odour threshold: 8-20 ppt
                                 –pM range



                                 My system will be capable
                                 to deal with this (?)
Sensitivity – Detection limit


                                     Amplification



                                Good knowledge of my electrical
                                circuit model of my system to target
                                usefully signal transduction.
                       Future Interests
                            Recognition – Affinity
                            Signal generation
                            Signal transduction



         100% electron-photon                   Photon semiconductors
            photon-electron                       –photonic crystals
              conversion

                                  Photonics -
                                  optoelectronics
Illumination                                                          Quantum
techniques, LED                                                       theory
                  Sensor               Ultraviolet     Energy
                  development          catastrophe     conservation

				
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posted:6/23/2013
language:English
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