A bioelectronic sensor based on canine olfactory nanovesicle–carbon nanotube hybrid structures for the fast assessment of food quality

Abstract

We developed an olfactory-nanovesicle-fused carbon-nanotube-transistor biosensor (OCB) that mimics the responses of a canine nose for the sensitive and selective detection of hexanal, an indicator of the oxidation of food. OCBs allowed us to detect hexanal down to 1 fM concentration in real-time. Significantly, we demonstrated the detection of hexanal with an excellent selectivity capable of discriminating hexanal from analogous compounds such as pentanal, heptanal, and octanal. Furthermore, we successfully detected hexanal in spoiled milk without any pretreatment processes. Considering these results, our sensor platform should offer a new method for the assessment of food quality and contribute to the development of portable sensing devices.

Bioelectronic nose and its application to smell visualization

“…The single-walled carbon nanotube (swCNT) was combined with a human olfactory receptor that was expressed in E. coli , and amylbutyrate was detected at a low concentration of 100 fM with high specificity [21]. In addition, bioelectronic noses were developed for a variety of purposes; for example, nanovesicle-based swCNT-FET sensors were developed for the detection of odor molecules such as heptanal that was produced from lung-cancer patients [30] and geosmin and 2-methylisoborneol for the real-time monitoring of water pollution [54], a CPNT-FET sensor was developed for the detection of odorants in gas phase, and a CNT sensor was immobilized with a canine olfactory receptor for the monitoring of hexanal from spoiled milk [41]. The recently developed bioelectronic noses therefore hold the potential for the detection of a variety of odor molecules like the human olfactory system.…”

“…Recently, several types of the bioelectronic nose have been developed for applications in various fields [1, 22, 30, 41, 54] including biomedical and industrial purposes such as disease diagnosis, food quality assessment, and environmental monitoring. In contrast to vision and hearing, smell cannot be exactly described or quantified because the classification and description of smell is quite subjective and abstractive.…”

Human dopamine receptor nanovesicles for gate-potential modulators in high-performance field-effect transistor biosensors

“…hDRD1 emitting nanovesicles were obtained through gentle agitation of the cells 36,37 . These nanovesicles possessed signaling capability for hDRD1-mediate signal transduction, such as G protein adenylyl cyclase and ion channels.…”

“…Furthermore, the functional study of GPCRs under cell-based assay, which is highly challenging masks for drug discovery and therapeutics, is often difficult because of low expression level and labor-intensive, time-consuming assay protocols [31][32][33][34][35] . Therefore, the new paradigm such as receptor-containing nanovesicles with functional GPCRs can be developed as gatepotential modulators in FET biosensing systems to overcome the limitations of conventional GPCR analytical methodologies for whole cell-like intracellular signal transduction 36,37 . In addition, the signal generated by the specific binding event of receptors and ligands can be amplified through the intracellular signaling in nanovesicles 36,37 .…”

“…Therefore, the new paradigm such as receptor-containing nanovesicles with functional GPCRs can be developed as gatepotential modulators in FET biosensing systems to overcome the limitations of conventional GPCR analytical methodologies for whole cell-like intracellular signal transduction 36,37 . In addition, the signal generated by the specific binding event of receptors and ligands can be amplified through the intracellular signaling in nanovesicles 36,37 . From this point of view, the realization of novel receptor-containing nanovesicles to target analytes is essential request to improve molecule sensing ability.…”