FiberLab: Development of lab-in-fiber devices for rapid chemical testing via thermal drawing

Rapid methods for the detection of contaminants and biochemical markers are needed in many areas such as environmental monitoring, food and beverage testing, and medical diagnosis. On-site analysis in particular is becoming a key component of safety and quality monitoring, when costs, equipment, or time limitations does not allow the use of conventional laboratory techniques. Centred around the needs for fast results, scalable fabrication, and ease-of-use, a new platform called FiberLab is developed: a low-cost multicapillary-format test capable of collecting and analysing µL-sized sample by colorimetric chemical assays. Most approaches rely on cumbersome fabrication process based on the chemical post-modification of capillaries but, thanks to the thermal drawing facility, is it possible to produce ready-to-use lab-in-fiber tests at large scale and low cost. The aim of the project is to expand the potential and performances of the platform by developing new sensing strategies and materials compatible with the thermal drawing process. In this perspective, many aspects of the device are studied. In terms of scalability, the process is studied and optimized in order to have long fiber with the correct width that mediates the capillary force with a proper volume of the analysed solution. The channels functionalization with the use of a polymeric coating is investigated: in order to obtain the colorimetric chemical reaction, it is necessary to include the reagents needed into the fiber with the use of a carrier. Moreover, different sensing strategies are then investigated with a specific focus aimed at increasing the sensitivity of every test up to the wet chemistry one: the versatility of the platform allows to reach a broad range of testing area. Starting from the food testing, a colorimetric assay to detect sulphite’s concentration in wine is implemented with the use of a well-established wet chemistry method, which is scaled and inserted into the fiber’s channels. The second explored field is the biomedical one: the goal is to provide basic tests that can be used in different situations. A study on lactate detection with enzymatic reactions is performed and on pH using common indicators.