Development of a generic and clinical relevant DNA- and Immuno-sensor platform (type 3). (R-1389)

Biosensors combine the selectivity of biological receptor molecules with sensitive optical or electrical transductiemethoden, with the purpose to observe analytes in relevant concentrations in different natural matrixes. Despite these promising symbiosis between biology and technology, just a few biosensor concepts are really suitable for routine use in daily clinical diagnostics for the detection of pathogens or for use in farmacogenomics. This requires a stable link between the biological and the technological component, and a rapid and sensitive signal detection, preferably without need for signal amplification. The possibility of miniaturization of the sensor platform is necessary so that in the future they can be integrated with microfluidics in lab-on-chip applications and also to make point-of-care use possible. Finally, it is important to demonstrate that this sensor maintaines a relevant sensitivity and specificity with measurements of the target in the naturally occurring matrixes. In previous doctoral work of the applicant was a generic biosensor platform developed based on diamond as transducer material, for one thing DNA molecules were linked to the construction of a DNA sensor, and for another antibodies were attached to the development of an immuno-sensor. This platform, which is very stable compared to existing platforms, show a rapid, label-free, selective and sensitive detection of DNA hybridization and antigen-detection made possible by using Electrochemical Impedance Spektroscopy (EIS). With the DNA sensor - Single nucleotide polymorphisms (SNP)-sensitivity was achieved. This means that the sensor is capable of tracing mutations in one nucleotide. SNP analysis plays not only an important part in the detection of many genetic disorders, but are also very important in the development of future so-called 'tailored medicine', or a tailor-made diagnosis and therapy. It is therefore extremely important that these SNP's can be detected in a fast and efficient way. For the immuno-sensor it was demonstrated that a clinically relevant concentration of CRP (10 nM) could be measured over a period of several minutes. Currently, the sensor operation, however,is mainly demonstrated in experimental settings. First of all, the conceptual immuno sensor will be further developed to a proof-of-principle of an immune sensor that is suitable for clinical applications. The specificity will be extended to naturally occurring matrices such as serum, saliva and cerebrospinal fluid. At the same time parameters will also be examined which increase the possible sensitivity to the molecular layer of the measurement system. Other parameters, such as a covalent attachment method for the antibodies,can improve the stability of the sensor response. Second, the development of the conceptual design of a DNA sensor to a proof-of-principle of a DNA sensor for clinical applications will be obtained. By this it is intended to extend the mutation detection in short DNA fragments to mutation detection in long target DNA fragments. Furthermore, by assigning unique exponential decay values to different mutations, a reliable identification of the relevant SNP's will be obtained.

Keywords:BIOSENSORS, IMMUNOLOGY

Disciplines:Basic sciences, Clinical sciences, Translational sciences