During the first part of the project, the researcher worked towards the integration of the gas sensors into LFA platforms. The sensors were first combined with nitrocellulose membranes to assess their capacity to measure gas from liquid samples added to the strips. To improve the understanding of the detection mechanism, a colorimetric probe-based system was introduced. The gas sensors were able to detect target gas directly from standards solutions, and as the product of enzymatic reactions.
The researcher then focused on the integration of the biological recognition materials (antibodies), the amplification element (enzyme and substrate) and flow-enhancing components (surfactants, protein-blocking agent) into the LFA platform with gas sensor detection. To minimize the risk and accelerate the development of the integrated system, a model immunoassay, including Immunoglobulin G (IgG) and commercial antibodies, was used as a proof-of-concept. The antibodies were modified accordingly to facilitate the detection of the target gas. This represented the first demonstration of the integration of gas sensors as detectors for LFA.
The use of gas sensors presented multiple challenges, though. For those reasons, the potential of integrating LFA and liquid-based sensors rather than gas sensors was also explored. This deviation of the project resulted in an innovative diagnostics platform, which is currently being assessed for further IP protection and commercialization.
At the final stage of the project, the researcher studied the potential of using gas sensors for food monitoring. The safe integration of gas sensors into packaging without compromising sensitivity, response rate, and stability remains a challenge. The researcher led the study of multiple protective membranes that could be used for the encapsulation of gas sensors into food packaging, with a particular focus on bagged spinach. The performance of the sensors to monitor spinach spoilage was evaluated by correlating the outputs with the microbial counts of the samples. Finally, the sensor system integrated with near-field communication (NFC)-enabled technology operated by a smartphone was demonstrated for the wireless, batteryless detection of spoiled samples. The innovation of this part of the project is currently being assessed for further commercialization.
The global objective of the project was achieved, and the integration of gas sensors as detectors for LFA systems was demonstrated. Actions to properly disseminate and exploit the project results were additionally undertaken. The findings of the project were presented at national and international conferences and led to 5 peer-reviewed publications.
