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This research aims to develop a portable optical biosensor for the quality assessment in food products. A flow cell, with the integration of Molecular Imprinted Polymer (MIP) technology, provides a colour displacement assay in the presence of the target molecule. A passive flow cell design based on capillary forces ensures the handling of the fluids. A built-in mini spectrometer analyses the colour intensity which relates to the presence of the target analyte. Depending on the MIP-manufacturing on different analytes, the sensor is versatile in the detection of different targets; the focus will be laid on food safety and traceability.

The simultaneous operation of multiple different semiconducting metal oxide (MOX) gas sensors is demanding for the readout circuitry. The challenge results from the strongly varying signal intensities of the various sensor types to the target gas. While some sensors change their resistance only slightly, other types can react with a resistive change over a range of several decades. Therefore, a suitable readout circuit has to be able to capture all these resistive variations, requiring it to have a very large dynamic range. This work presents a compact embedded system that provides a full, high range input interface (readout and heater management) for MOX sensor operation. The system is modular and consists of a central mainboard that holds up to eight sensor-modules, each capable of supporting up to two MOX sensors, therefore supporting a total maximum of 16 different sensors. Its wide input range is archived using the resistance-to-time measurement method. The system is solely built with commercial off-the-shelf components and tested over a range spanning from 100 &Omega, to 5 G&Omega, (9.7 decades) with an average measurement error of 0.27% and a maximum error of 2.11%. The heater management uses a well-tested power-circuit and supports multiple modes of operation, hence enabling the system to be used in highly automated measurement applications. The experimental part of this work presents the results of an exemplary screening of 16 sensors, which was performed to evaluate the system&rsquo, s performance.

A high throughput solid-phase enzyme immunoassay (EIA) platform based on lab-on-card (LOC) microfluidics is proposed. In addition, a first step towards label-free detection of immunosorbent assays based on Electrical Impedance Spectroscopy (EIS) is made. The reported LOCs are developed by alternately stacking PET layers and adhesive layers. LOCs can be equipped with aluminium interdigitated electrodes and coated with polystyrene to perform EIS. Furthermore, the end product of a colorimetric ELISA test was flushed into a LOC and subsequently the optical density was measured. The preliminary tests provide a stable base for the label-free EIA based on EIS. This work is funded by the HEALTHY AGING project which is carried out under Interreg V-A Euregio Meuse - Rhine and is supported by the European Union and The European Regional Development Fund and with financial support of province of Limburg - Belgium.

This work aims to translate lab-scale techniques for the detection of diseases towards lab-on-card(LOC) devices. Indeed, these point-of-care(POC) tests allow detecting diseases in resource-limited areas. The necessary functions of the LOC can be split up into four different sections: extraction of the cells from the biological sample, lysis of the cells to harvest DNA, DNA amplification based on loop-mediated isothermal amplification(LAMP) and DNA detection by adding SYBR Green I nucleic acid stain. These functionalities have separately been tested on LOCs. The results of the individual functions show that a fully functional POC device is an achievable goal. Financial support of the special research fund BOF of Hasselt University and VLIRUOS project MA2018TEA467A104.

A high throughput solid-phase enzyme immunoassay (EIA) platform based on lab-on-card (LOC) microfluidics is proposed. In addition, a first step towards label-free detection of immunosorbent assays based on Electrical Impedance Spectroscopy (EIS) is made. The reported LOCs are developed by alternately stacking PET layers and adhesive layers. LOCs can be equipped with aluminium interdigitated electrodes and coated with polystyrene to perform EIS. Furthermore, the end product of a colorimetric ELISA test was flushed into a LOC and subsequently the optical density was measured. The preliminary tests provide a stable base for the label-free EIA based on EIS. This work is funded by the HEALTHY AGING project which is carried out under Interreg V-A Euregio Meuse - Rhine and is supported by the European Union and The European Regional Development Fund and with financial support of province of Limburg - Belgium.

The choice of suitable semiconducting metal oxide (MOX) gas sensors for the detection of a specific gas or gas mixture is time-consuming since the sensor&rsquo, s sensitivity needs to be characterized at multiple temperatures to find its optimal operating conditions. To obtain reliable measurement results, it is very important that the power for the sensor&rsquo, s integrated heater is stable, regulated and error-free (or error-tolerant). Especially the error-free requirement can be only be achieved if the power supply implements failure-avoiding and failure-detection methods. The biggest challenge is deriving multiple different voltages from a common supply in an efficient way while keeping the system as small and lightweight as possible. This work presents a reliable, compact, embedded system that addresses the power supply requirements for fully automated simultaneous sensor characterization for up to 16 sensors at multiple temperatures. The system implements efficient (avg. 83.3% efficiency) voltage conversion with low ripple output (&lt, 32 mV) and supports static or temperature-cycled heating modes. Voltage and current of each channel are constantly monitored and regulated to guarantee reliable operation. To evaluate the proposed design, 16 sensors were screened. The results are shown in the experimental part of this work.

Electrical Impedance Tomography (EIT) is a non-invasive, non-ionizing and inexpensive imaging modality that is used to image the conductivity distribution inside the subject under test. In (bio)medical and medical applications, the different conductivity distributions can show the structural and functional properties of the subject, this due to the inhomogeneous bioelectrical properties of tissue. Having this knowledge, a sensor is developed to monitor the cell growth in the spatial domain. This work is funded by the BIOMAT project which is carried out under Interreg V-A grensregio Vlaanderen - Nederland and is supported by the European Union and The European Regional Development Fund and with financial support of province of Limburg - Belgium.

In this work a biomimetic sensor based on the heat-transfer method(HTM) and molecularly imprinted polymers(MIPs) has been developed as a paper-based lab-on-chip device. These microfluidic paper-based analytical devices (μPADs) are considerably smaller, faster and cheaper compared to its lab-sized predecessors. They can be used, disposed after usage and easily replaced for a new test without the requirement of expensive equipment. This makes it the ideal sensor for detecting molecules in point-of-care testing. This work is funded by the BIOMAT project which is carried out under Interreg V-A grensregio Vlaanderen - Nederland and is supported by the European Union and The European Regional Development Fund and with financial support of province of Limburg - Belgium.

The Heat-Transfer Method (HTM) is a promising transducing technique capable of performing a broad range of bioanalytical tasks. To demonstrate the capabilities of the sensor, experiments on the detection of Bisphenol A (BPA) in a buffer solution have been executed. Hereby bulk polymerized Molecularly Imprinted Polymers (MIPs) have been used as the biomimetic receptor.

A biomimetic sensor platform capable of performing electrochemical measurements for the detection of molecules was developed by incorporating molecularly imprinted polymers (MIPs) into microfluidic paper-based analytical devices(µPADs). The usage of µPADs in combination with electrochemical measurements vastly improves several parameters compared to lab-sized electrochemical setups. Interdigitated electrodes were utilized, this way no top electrode is needed. The amplitude of the impedance was monitored and a complete impedance spectrum was measured continuously. The combination of low-cost, disposable paper-based microfluidics and electrochemical read-out, make an ideal point-of-care application. This work is funded by the BIOMAT project which is carried out under Interreg V-A grensregio Vlaanderen - Nederland and is supported by the European Union and The European Regional Development Fund and with financial support of province of Limburg - Belgium.

Black lipid membranes (BLMs) are planar lipid bilayers that can be formed in porous supports such as filters. A BLM as a biomimetic membrane has important applications in, for instance, biosensing and drug-permeability assays. In the present study, BLMs were formed in the pores of three different filters to investigate their ability to support the formation of a high-quality lipid bilayer. Poly (vinylidene fluoride) (PVDF), poly(acrylonitrile) (PAN), and polypropylene/polyethylene (PP/PE) filters were utilized as filter supports, and the bilayer formation was monitored in situ by capacitance measurements. The maximum capacitance was obtained for PVDF (5.34Fcm(-2)) versus PP/PE and PAN (2.95 and 0.91Fcm(-2), respectively). Additionally, BLM leakage current measurements by wave deviation provided consistent results. Thickness and compactness of the bilayers were evaluated using pore forming protein (ClyA) insertion. The results show that PVDF with the highest porosity level was the most suitable support for BLM formation. The optimal thickness for the BLM in PVDF was 3-5nm, where the most efficient protein insertion took place, in comparison with other filters.