Vapor Sensors Using Olfactory Proteins Coupled to Carbon

Nanotubes

Mitchell Lerner, Brett Goldsmith, Joe Mitala, Bohdana Discher, Paul Rhodes, A.T. Charlie Johnson

University of PennsylvaniaAPS March 2010

Biological Olfaction

• Number of discernable smells is much greater than the number of types of olfactory receptor cells

(350 sensor types detect >10,000 odors for humans)

http://nobelprize.org/

Mammal Types of Olfactory Receptor

Cells

Human 350

Mouse 1000

Rat 1500

Dog 1100

Experimental Objective

• Integrate biology with nanotechnology

http://nobelprize.org/

Nanotube Transistors

• Use standard techniques to construct state of the art CNT transistors

Nanotube Functionalization

Bare NanotubeDiazonium saltEDCNHSNTAOlfactory receptor protein in micelles

Experimental Design:Attachment

• Confirmation of protein attachment to nanotubes

1mm

Reproducible Sensing

• curves from 3 experiments showing a reproducible response to eugenol for mOR174-9

• mOR 174-9 responds to eugenol in vivo

blue arrow – inert gas flush

green arrow – eugenol exposure

Sensor Timing

• experiment showing a response to cyclohexanone for mOR 256-17

• mOR 256-17 responds to cyclohexanone in vivo• Initial response k-1 3s, secondary response is

30s• Recovery k-1 is 30s.

Concentration Dependence

• experiments showin responses for mOR 203-1• mOR 203-1 responds to 2-heptanone in vivo• fMRI studies show identical responses to 2-

heptanone and n-amyl acetate in mice

mOR 174-9

mOR 203-1

mOR 256-17

Each of the three proteins gives a different set of reproducible, concentration dependent responses

Summary• We reproduced many properties of

biological sensing in an electronic device.

• Proteins are maintaining some features found in vivo

• First use of G-protein coupled receptors in electronic sensors

• Potential for application in hazardous material detection and pharmaceutical testing

Acknowledgements

Evolved Machines Paul Rhodes, Sam Khamis, Ryan Jones

Johnson Group - Penn

A.T.Charlie Johnson, Brett Goldsmith, Mitchell Lerner, Ye Lu

Discher Group - Penn

Bohdana Discher, Joe Mitala

Brand Group - Monell

Joe Brand, Jesusa Josue, Alan Gelperin

Sliger Group - UIUC Stephen Sliger, Tim Baybert

Luetje Group - UMiami

Chuck Luetje

DARPA RealNose Project