Electrospun composite nanofibers as sensors for food analysis

Electrospinning is a highly versatile technique used to produce micro- and nanofibers of varied sizes and morphologies. The high flexibility of electrospun nanofibers combined with an extremely high surface area/volume ratio and the possibility of chemical functionalization (with metallic nanoparticles, enzymes, carbon nanotubes, graphene, etc.) make them particularly suitable for sensor design and fabrication, including optical, chemical, and electrochemical sensors for food and beverage analyses. For instance, such sensors can be applied to monitor food and beverage quality regarding food pathogens (bacteria, fungus, etc.) and other contaminants. In this chapter, we present very recent results on the use of electrospinning to produce composite nanofibers with varied morphologies and chemical functionalization, aiming to be applied as active layers in food sensors with improved sensitivity, the limit of detection, robustness, and portability. Additionally, another fiber-forming technique called solution blow spinning (SB-Spinning), which allows for obtaining nanofibers with similar features of those obtained by electrospinning, but with a higher output rate and without the use of a high-voltage supply, is also presented as a potential alternative for producing composite nanofibers. The sensors produced by these fiber-forming techniques can be used to detect food contamination regarding bacteria, pesticides, and other contaminants, which are throughout discussed in this chapter.