All of the PoC-ID goals were achieved during the project duration. Based on a specification document com-prising the overall system requirements from the user’s perspective, technological demands were defined. Sequences of host biomarkers and viral proteins were selected for in vitro screening of new capture mole-cules. The focus for the first phase was on device design and process development aiming for proof-of-concept prototypes for BioMEMS and BioGrFET and flexible technology toolboxes (functionalisation schemes, packaging and device design). During this first phase, the sensors showed good results in artificial environments and buffer solutions. Early definition of the protocols for sample collection and storage en-sured sample availability for the sensor evaluation phase. Also, early development of chemistry for immobi-lisation of capture molecules to the sensors paved the way for Biosensor development. In the second half of the project, the performance of the BioGrFET to detect the PoC-ID targets was optimised using theoretical modelling. By fabricating 5 batches of the device, the optimum parameters were found, experimentally realised and linked to modelling results. Specific biorecognition molecules (Spiegelmers) against three iden-tified targets (CXCL8, CCL5, and CXCL10) have been successfully immobilised to surfaces via a Carbon Nanomembrane (CNM) nanointerposer combined with the BioGrFET sensor. Such functionalised sensors showed good results on exposure to CXCL8 target in a laboratory setup and even in a clinical setting. The sensor thus covers the clinically most relevant range of CXCL8 for the diagnosis of RSV [Respiratory Syncyti-al Virus]. Furthermore, the clinical value of inflammatory markers present in the NPS [nasopharyngeal swab] during RSV infection have been further explored and CXCL8 was confirmed as a biomarker able to differentiate children with moderate and severe disease and to determine who needed supportive care in a hospital. Testing of the PoC-ID device was done under lab conditions and in a clinical environment, proving the applicability of PoC-ID results for the target applications.
Overall, an integrated PoC-ID benchtop device has been designed and developed which integrates the fluidics system, the driving electronics and sensor module. The device is able to acquire measurements from both the BioGrFET and BioMEMS sensors and provides accurate analysis results in only approx. 6 minutes. Hence, it was demonstrated, that PoC-ID results are a large step towards low cost and fast detection of specific biomarkers in the clinically relevant range.
