Nanoelectronics for biosensor technologies

©https://doi.org/10.1021/acs.na

About us

(Bio)sensor development enabled by advances in micro- and nanofabrication as well as microfluidics has been a growing field since decades ago, aiming at facilitating the task of disease detection or physiological parameter monitoring. We have seen biosensor evolution from the first glucose detecting devices in the 60s to be used in medical facilities to the more recent point-of-care devices handheld by the patients themselves at the comfort of their own home. Among the existing sensors, those relying on nanomaterials and nanostructures as sensing surface offer the highest sensitivity, as demonstrated during the last two decades, even reaching the possibility of single molecule detection. Those with transduction mechanisms based on electrical effects (electrochemical, potentiometric, impedimetric, etc.) provide the finest suitability for miniaturization, requiring simpler setups where arrays of many sensors can be combined for a label-free and continuous analysis of the analyte of interest. In this way, full integration possibilities exist in combination with further circuit packaging for signal processing which require standard electronic microfabrication processes.

©TUD

In the research line “Nanoelectronics for sensor technologies”, we aim at covering the necessary steps for the development of ultrasensitive gas sensors and biosensors. We make use of both top-down and bottom-up fabrication routes to obtain nanomaterials that will be later integrated in electronic supports, rigid or flexible. We take care of introducing biochemical modifications to achieve the selectivity toward specific analytes of interest. We manipulate samples and reagents with the help of microfluidics, as smart tool for the controlled mixing, delivery and parallelization at small scales. Through interaction with other members of the Chair, we perform theoretical analysis of our devices and introduce machine learning capabilities that boost their performance. Beyond simply detecting target molecules, we investigate and get insights on new detection techniques and phenomena that take place thanks to the presence of the nanoscale matter, and exploit unexpected findings toward new applications.

Research topics

Gas sensing

We refer to novel and reliable strategies to develop fast response, highly sensitive and selective, low-cost gas sensors. Gas sensors are extensively utilized in monitoring air quality, ensuring public safety, breathe analysis for disease diagnosis, and providing useful information in our surrounding environment. A myriad of devices based on traditional metal oxide semiconductor materials have been developed, nevertheless, their selectivity and power-consumption are still far from satisfactory. To address the selectivity issues of gas sensors, on one hand, in combination with machine learning techniques, each gas could be represented by unique feature vector (called gas fingerprint), which could enhance the selectivity. On the other hand, by introducing specific foreign functional materials (noble metal nanoparticles, MOX particles, etc.) onto the sensing substrate materials (graphene, CNT, MOFs, or other 2D materials), due to the specific bonding interaction creation between analyte molecules and functionalized molecules, the selectivity could also be enhanced. More beyond the gas detection in stationary module, gas sensors with fast response and excellent selectivity characteristics are available to be integrated into mobile devices (e.g., smartphone, ground-dog, air vehicles, etc.), showing promising applications in olfactory navigation field, such as localization of gas sources in complex environments.

©TUD

Biosensing

The pandemic situation that we are dealing with has shown very clearly the importance of medical diagnostics: there is a high demand for early detection of possible pathogens in order to take immediate action such as preventing the spread of any infectious disease and moreover to start medical actions when the disease is not at a critical stage yet. Apart from Covid-19, the early detection of multiple diseases such as cancer, Alzheimer, Parkinson, etc. is relevant. For diagnostics of the maladies, physicians have to rely on the testing of specific biomarkers whose analysis is typically executed in dedicated labs – a time and work-intense procedure. To circumvent these impairments, the successful development of biosensors which are capable to detect analytes preferably in real-time and on the point of care- while being low-cost and easy to use by nurses, technicians, or even the patients themselves- will improve the field of medical diagnostics.

Our group offers a variety of knowledge and expertise in development of biosensors for point-of-care measurements. We work with multiple transduction platforms that range from electronic sensors (field-effect transistors, chemiresistors) based on 1D/2D materials (silicon nanowires, carbon nanotubes, graphene…) to electrochemical sensors (impedance, amperometry). We can manufacture the sensors on non-rigid substrates, too. By performing an appropriate surface modification with fitting receptors, we are able to detect analytes down to very low concentration ranges. Further, we are interested in the application of sensors for in vivo purposes and hence focus on the incorporation of appropriate surface coatings to achieve biocompatibility of the sensors – while keeping them sensitive and selective.

©TUD

Neuromorphics

Strong scientific efforts try to emulate brain function to avoid the bottleneck imposed by the data communication rate in the von Neumann architecture. With the development of the so-called neuromorphic devices, the main focus has been put on the synaptic function as key elements interlacing neurons. However, the neuron is also an important element integrating non-linearly the received information in its membrane and generating new signals to other neurons. In our group, we use field-effect transistors as devices that resemble neuron structure with better fidelity, with a signal that travels over a long distance from an input to an output (source and drain) and which is modulated on its way by the input of another terminal (gate). We incorporate the non-linear integration of arriving input patterns by modifying the surface of the semiconductor channel with polarizable films, and resulting in sigmoidal learning dynamics and forgetting/erasing processes.

©TUD

possible master\diploma thesis

We offer exciting projects in the research topics described above. If you are interested in one of the following topics please do contact us.

Projects

Publications

Nanoelectronics for biosensor technologies

©https://doi.org/10.1021/acs.na

About us

(Bio)sensor development enabled by advances in micro- and nanofabrication as well as microfluidics has been a growing field since decades ago, aiming at facilitating the task of disease detection or physiological parameter monitoring. We have seen biosensor evolution from the first glucose detecting devices in the 60s to be used in medical facilities to the more recent point-of-care devices handheld by the patients themselves at the comfort of their own home. Among the existing sensors, those relying on nanomaterials and nanostructures as sensing surface offer the highest sensitivity, as demonstrated during the last two decades, even reaching the possibility of single molecule detection. Those with transduction mechanisms based on electrical effects (electrochemical, potentiometric, impedimetric, etc.) provide the finest suitability for miniaturization, requiring simpler setups where arrays of many sensors can be combined for a label-free and continuous analysis of the analyte of interest. In this way, full integration possibilities exist in combination with further circuit packaging for signal processing which require standard electronic microfabrication processes.

©TUD

In the research line “Nanoelectronics for sensor technologies”, we aim at covering the necessary steps for the development of ultrasensitive gas sensors and biosensors. We make use of both top-down and bottom-up fabrication routes to obtain nanomaterials that will be later integrated in electronic supports, rigid or flexible. We take care of introducing biochemical modifications to achieve the selectivity toward specific analytes of interest. We manipulate samples and reagents with the help of microfluidics, as smart tool for the controlled mixing, delivery and parallelization at small scales. Through interaction with other members of the Chair, we perform theoretical analysis of our devices and introduce machine learning capabilities that boost their performance. Beyond simply detecting target molecules, we investigate and get insights on new detection techniques and phenomena that take place thanks to the presence of the nanoscale matter, and exploit unexpected findings toward new applications.

Research topics

Gas sensing

We refer to novel and reliable strategies to develop fast response, highly sensitive and selective, low-cost gas sensors. Gas sensors are extensively utilized in monitoring air quality, ensuring public safety, breathe analysis for disease diagnosis, and providing useful information in our surrounding environment. A myriad of devices based on traditional metal oxide semiconductor materials have been developed, nevertheless, their selectivity and power-consumption are still far from satisfactory. To address the selectivity issues of gas sensors, on one hand, in combination with machine learning techniques, each gas could be represented by unique feature vector (called gas fingerprint), which could enhance the selectivity. On the other hand, by introducing specific foreign functional materials (noble metal nanoparticles, MOX particles, etc.) onto the sensing substrate materials (graphene, CNT, MOFs, or other 2D materials), due to the specific bonding interaction creation between analyte molecules and functionalized molecules, the selectivity could also be enhanced. More beyond the gas detection in stationary module, gas sensors with fast response and excellent selectivity characteristics are available to be integrated into mobile devices (e.g., smartphone, ground-dog, air vehicles, etc.), showing promising applications in olfactory navigation field, such as localization of gas sources in complex environments.

©TUD

Biosensing

The pandemic situation that we are dealing with has shown very clearly the importance of medical diagnostics: there is a high demand for early detection of possible pathogens in order to take immediate action such as preventing the spread of any infectious disease and moreover to start medical actions when the disease is not at a critical stage yet. Apart from Covid-19, the early detection of multiple diseases such as cancer, Alzheimer, Parkinson, etc. is relevant. For diagnostics of the maladies, physicians have to rely on the testing of specific biomarkers whose analysis is typically executed in dedicated labs – a time and work-intense procedure. To circumvent these impairments, the successful development of biosensors which are capable to detect analytes preferably in real-time and on the point of care- while being low-cost and easy to use by nurses, technicians, or even the patients themselves- will improve the field of medical diagnostics.

Our group offers a variety of knowledge and expertise in development of biosensors for point-of-care measurements. We work with multiple transduction platforms that range from electronic sensors (field-effect transistors, chemiresistors) based on 1D/2D materials (silicon nanowires, carbon nanotubes, graphene…) to electrochemical sensors (impedance, amperometry). We can manufacture the sensors on non-rigid substrates, too. By performing an appropriate surface modification with fitting receptors, we are able to detect analytes down to very low concentration ranges. Further, we are interested in the application of sensors for in vivo purposes and hence focus on the incorporation of appropriate surface coatings to achieve biocompatibility of the sensors – while keeping them sensitive and selective.

©TUD

Neuromorphics

Strong scientific efforts try to emulate brain function to avoid the bottleneck imposed by the data communication rate in the von Neumann architecture. With the development of the so-called neuromorphic devices, the main focus has been put on the synaptic function as key elements interlacing neurons. However, the neuron is also an important element integrating non-linearly the received information in its membrane and generating new signals to other neurons. In our group, we use field-effect transistors as devices that resemble neuron structure with better fidelity, with a signal that travels over a long distance from an input to an output (source and drain) and which is modulated on its way by the input of another terminal (gate). We incorporate the non-linear integration of arriving input patterns by modifying the surface of the semiconductor channel with polarizable films, and resulting in sigmoidal learning dynamics and forgetting/erasing processes.

©TUD

possible master\diploma thesis

We offer exciting projects in the research topics described above. If you are interested in one of the following topics please do contact us.

Projects

Publications