Characterization and functionalization of silicon nano-ribbon based biosensor to detect biomolecules

Contacts:

Andrea Pfreundt, anpf@nanotech.dtu.dk,  Azeem Zulfiqar, azzu@nanotech.dtu.dk

The need for point of care devices to detect biomarkers has increased in recent years as the demand for patient screening in order to detect diseases in an early stage has risen. More efficient screening and disease monitoring shows great promise in the prevention of severe cases and the development of personalized treatments. Devices that are capable of detecting small concentrations of biomarkers play an important role in this field, as more specific biomarkers are discovered as disease indicators, leading to possibilities for quick diagnosis. Recently, silicon nano-ribbons based biosensors have shown promising results in the detection of biomolecules like proteins, viruses or DNA. The sensing principle of the device is based on the Field Effect Transistor behavior of the silicon nano-ribbon. The binding of charged biomolecules to the surface acts as a gate and affects the charge carrier distribution inside the ribbon which results in a conductivity change that can be measured.

The first part of the project is to characterize the field effect behavior of the silicon nanoribbons that have been fabricated at the NaBIS group and study the electrical behavior of the sensor device in different environments such as air and different buffer solutions. The second part would be to modify the surface of the ribbons and attach bioreceptor molecules (this process is called functionalization) that are specific to the targeted analyte (biomarker) and test the sensor response at varying pH, to further characterize the sensor sensitivity.

The goal of the project is to define the sensitivity limits of the biosensor by investigating the field effect behavior of the device and the response to immobilized proteins.

You will be working with

-          Electrical measurement setup which involves working with labview, keithley systems.

-          Biomolecules such as antibodies

silicon surface chemistry