Download Normvorlage

BIO(MIMETIC) ELECTROCHEMICAL SENSORS:
PRESENT, PAST AND FUTURE
Frieder W. Schellera, AysuYarmanb,Frank F. Bierc
aUniversity
of Potsdam, Institute of Biochemistry and Biology, Karl-LiebknechtStrasse 25-26, D-14476 Potsdam, Germany
bTurkish-German University, Faculty of Science, Molecular Biotechnology, Sahinkaya
Cad. No.:86, 34820 Beykoz, Istanbul, Turkey
cFraunhofer Institute for Cell Therapy and Immunology, Branch Bioanalytics and
Bioprocesses (IZI-BB), Am Mühlenberg 13, D-14476 Potsdam, Germany
Biosensors represent the technical counter part of sense organs by coupling
enzymes, antibodies, nucleic acids, receptors, organelles, cells, and tissues with a
chemical or physical sensor.
Inaugurated by L.C. Clarck in the sixties the development of electrochemical
biosensors mainly focused on glucose oxidase and (PQQ) glucose dehydrogenase
for blood glucose measurement. Ten years later direct heterogeneous electron
transfer has been achieved by us for cytochrome c, hemoglobin and different P450
enzymes. This approach has been extended to develop sensors for the reactive
oxygen species (ROS) superoxide and peroxide or for different xenobiotics and
drugs. At present, electrochemical glucose sensors cover almost 75 percent of the17
billion US Dollars world marked of biosensors. On the other hand, electrochemical
immunosensors or nucleic acid chips reached not a comparable acceptance and
optical principles are considerably more applied in these fields.
In order to mimic the active sites of antibodies or enzymes by synthetic mimics socalled „molecularly imprinted polymers”(MIPs) have been developed. Functional
monomers are polymerised in the presence of the target analyte and after
polymerisation the template molecules are removed, providing binding sites ideally
complementary in size, shape and functionality to the template. So far the affinity and
catalytic activity of MIPs have in general been lower than those of their biological
counterparts. MIP–based electrochemical sensors have the potential to complement
biosensor and biochips for the measurement of low molecular weight substances,
proteins, viruses and living cells.