Limits...
Bio-benchmarking of electronic nose sensors.

Berna AZ, Anderson AR, Trowell SC - PLoS ONE (2009)

Bottom Line: The comparison also highlights some important questions about the molecular nature of fly ORs.The comparative approach generates practical learnings that may be taken up by solid-state physicists or engineers in designing new solid-state electronic nose sensors.It also potentially deepens our understanding of the performance of the biological system.

View Article: PubMed Central - PubMed

Affiliation: CSIRO Entomology and CSIRO Food Futures Flagship, Canberra, Australian Capital Territory, Australia.

ABSTRACT

Background: Electronic noses, E-Noses, are instruments designed to reproduce the performance of animal noses or antennae but generally they cannot match the discriminating power of the biological original and have, therefore, been of limited utility. The manner in which odorant space is sampled is a critical factor in the performance of all noses but so far it has been described in detail only for the fly antenna.

Methodology: Here we describe how a set of metal oxide (MOx) E-Nose sensors, which is the most commonly used type, samples odorant space and compare it with what is known about fly odorant receptors (ORs).

Principal findings: Compared with a fly's odorant receptors, MOx sensors from an electronic nose are on average more narrowly tuned but much more highly correlated with each other. A set of insect ORs can therefore sample broader regions of odorant space independently and redundantly than an equivalent number of MOx sensors. The comparison also highlights some important questions about the molecular nature of fly ORs.

Conclusions: The comparative approach generates practical learnings that may be taken up by solid-state physicists or engineers in designing new solid-state electronic nose sensors. It also potentially deepens our understanding of the performance of the biological system.

Show MeSH

Related in: MedlinePlus

A cartoon to illustrate the relative coverage and overlap of dORs (A) and MOx (B) sensors in odorant space.Principal component analyses were performed separately for the responses of MOx sensors and dORs to 1/100 dilutions of the 110 test compounds. The panels depict the locations of (A) the twelve representative dORs (asterisked in Table S4) and (B) the 12 MOx sensors, in the first two principal components of the loading plots from the PCAs. In each panel the relative half-widths of the tuning curves are used as the radii to generate circles centred on the respective receptors/sensors.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2712691&req=5

pone-0006406-g007: A cartoon to illustrate the relative coverage and overlap of dORs (A) and MOx (B) sensors in odorant space.Principal component analyses were performed separately for the responses of MOx sensors and dORs to 1/100 dilutions of the 110 test compounds. The panels depict the locations of (A) the twelve representative dORs (asterisked in Table S4) and (B) the 12 MOx sensors, in the first two principal components of the loading plots from the PCAs. In each panel the relative half-widths of the tuning curves are used as the radii to generate circles centred on the respective receptors/sensors.

Mentions: An ideal sensor array for volatile compounds would sample all points in odorant space, using multiple independent sensors. We used a graphical approach to compare, qualitatively, the degree to which the coverage, overlap and independence of dORs and MOx sensors approaches this ideal. (Figure 7). PCAs were run separately for the responses of MOx sensors and 12 of the dORs to 1/100 dilutions of the 110 test compounds. In each case the relative half-widths of the tuning curves were used as the radii to generate circles centred on the location of the respective receptors/sensors in the PCA loading plot. Although this comparison is not strictly quantitative, it illustrates the findings that a set of 12 insect ORs can sample much broader regions of odorant space independently and redundantly than the same number of MOx sensors. The relative effectiveness of the olfactory system of the living fly, which expresses 48 odorant receptors of the seven transmembrane class, rather than the 12 depicted in Figure 7, would be underestimated by this approach.


Bio-benchmarking of electronic nose sensors.

Berna AZ, Anderson AR, Trowell SC - PLoS ONE (2009)

A cartoon to illustrate the relative coverage and overlap of dORs (A) and MOx (B) sensors in odorant space.Principal component analyses were performed separately for the responses of MOx sensors and dORs to 1/100 dilutions of the 110 test compounds. The panels depict the locations of (A) the twelve representative dORs (asterisked in Table S4) and (B) the 12 MOx sensors, in the first two principal components of the loading plots from the PCAs. In each panel the relative half-widths of the tuning curves are used as the radii to generate circles centred on the respective receptors/sensors.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2712691&req=5

pone-0006406-g007: A cartoon to illustrate the relative coverage and overlap of dORs (A) and MOx (B) sensors in odorant space.Principal component analyses were performed separately for the responses of MOx sensors and dORs to 1/100 dilutions of the 110 test compounds. The panels depict the locations of (A) the twelve representative dORs (asterisked in Table S4) and (B) the 12 MOx sensors, in the first two principal components of the loading plots from the PCAs. In each panel the relative half-widths of the tuning curves are used as the radii to generate circles centred on the respective receptors/sensors.
Mentions: An ideal sensor array for volatile compounds would sample all points in odorant space, using multiple independent sensors. We used a graphical approach to compare, qualitatively, the degree to which the coverage, overlap and independence of dORs and MOx sensors approaches this ideal. (Figure 7). PCAs were run separately for the responses of MOx sensors and 12 of the dORs to 1/100 dilutions of the 110 test compounds. In each case the relative half-widths of the tuning curves were used as the radii to generate circles centred on the location of the respective receptors/sensors in the PCA loading plot. Although this comparison is not strictly quantitative, it illustrates the findings that a set of 12 insect ORs can sample much broader regions of odorant space independently and redundantly than the same number of MOx sensors. The relative effectiveness of the olfactory system of the living fly, which expresses 48 odorant receptors of the seven transmembrane class, rather than the 12 depicted in Figure 7, would be underestimated by this approach.

Bottom Line: The comparison also highlights some important questions about the molecular nature of fly ORs.The comparative approach generates practical learnings that may be taken up by solid-state physicists or engineers in designing new solid-state electronic nose sensors.It also potentially deepens our understanding of the performance of the biological system.

View Article: PubMed Central - PubMed

Affiliation: CSIRO Entomology and CSIRO Food Futures Flagship, Canberra, Australian Capital Territory, Australia.

ABSTRACT

Background: Electronic noses, E-Noses, are instruments designed to reproduce the performance of animal noses or antennae but generally they cannot match the discriminating power of the biological original and have, therefore, been of limited utility. The manner in which odorant space is sampled is a critical factor in the performance of all noses but so far it has been described in detail only for the fly antenna.

Methodology: Here we describe how a set of metal oxide (MOx) E-Nose sensors, which is the most commonly used type, samples odorant space and compare it with what is known about fly odorant receptors (ORs).

Principal findings: Compared with a fly's odorant receptors, MOx sensors from an electronic nose are on average more narrowly tuned but much more highly correlated with each other. A set of insect ORs can therefore sample broader regions of odorant space independently and redundantly than an equivalent number of MOx sensors. The comparison also highlights some important questions about the molecular nature of fly ORs.

Conclusions: The comparative approach generates practical learnings that may be taken up by solid-state physicists or engineers in designing new solid-state electronic nose sensors. It also potentially deepens our understanding of the performance of the biological system.

Show MeSH
Related in: MedlinePlus