Biosensor using impedimetric real-time monitoring

A bio-sensing device suitable for the detection of target DNA and/or RNA and/or the characterization (allocation) of point mutations in target DNA and/or RNA, said bio-sensing device comprising at least:

• a flow cell equipped with an impedimetric analyzer,
• a biocompatible and inert substrate disposed against the flow cell, such that at least one surface of said substrate is exposed to liquid flow within the flow cell, said substrate having covalently bound probe DNA and/or RNA on its at least one exposed surface, said probe DNA and/or RNA being configured to bind the target DNA and/or RNA,
• a pumping system and switching valve connected to said flow cell,
• a first liquid supply comprising a electrolytic solution connected to said pumping system and to said switching valve,
• a second liquid supply comprising a chemical that is able to achieve denaturation of DNA and/or RNA such that any of the target DNA and/or RNA that is bound to the probe DNA and/or RNA is released from the probe DNA and/or RNA when exposed to the chemical, the second liquid supply being connected to said pumping system and to said switching valve,
• a means for obtaining a value representative for the impact of the chemical on the impedance of the electrolytic solution said means for obtaining the value representative for the impact of the chemical on the impedance of the electrolytic solution being operatively connected to the impedimetric analyzer, and
• a means for determining the amount of the target DNA and/or RNA and/or an allocation of point mutation(s) within the target DNA and/or RNA by calculating the denaturation-time constant based on the difference between the first and second impedance value and corrected for the impact of the chemical by the value representative for such impact, said means for determining the amount and/or allocation being operatively connected to the means for obtaining the value representative for the impact of the chemical on the impedance of the electrolytic solution.