Artificial nose using electrophysiology coupled to nanowires: Towards single molecule sensitivity with single atom resolution on chemical species

University Of California-Irvine, Irvine CA

Investigators

Abstract

The goal of this project is to develop an engineered electronic nose that can “smell” chemicals and determine what kind of chemicals they are. Each nose will smell only one kind of chemical. The chemicals could be anything that natural noses can detect, e.g., dynamite, drugs, viruses, toxic chemicals, etc. Receptors from biological noses will be attached to tiny electrical sensors. This technique lays the groundwork for developing high precision chemical detection in general, which can be utilized in a variety of applications requiring high precision process control (i.e., advanced manufacturing.) Since the sensor is electronic, it could be integrated into a massively parallel electronic nose system with signal recognition based on hundreds of different sensors onto one chip. An educational outreach program to share the technology with K-12 will be implemented. This outreach program is designed to reach K-12 educationally disadvantaged students from local neighborhoods with predominantly ethnic-minority student populations. The end goal of this project is an engineered electronic nose with specificity towards analytes that differ by as little as one carbon atom and with the sensitivity of a living system able to electrically register a single molecule of analyte. The analyte could be anything that natural noses can detect, e.g., TNT, cocaine, aromatics, volatile organic compounds (VOCs) etc. The strategy proposed is to genetically engineer a fused olfactory odorant receptor (OR, a membrane bound protein with exquisite selectivity) to an ion channel protein, which opens in response to binding of the ligand to the OR. The lipid bilayer supporting the fused sensing protein would be intimately attached to a nanowire or nanotube network (either via a covalent tether or a non-covalent physisorption process), which would electrically detect the opening of the ion channel, and hence the binding of a single ligand to a single OR protein domain. In summary, the project’s goal will be achieved by the combination of these three technological advances (fused OR + ion channel protein, nanowire sensing of single ion channel activity, and lipid bilayer to nanotube tethering chemistry) with the results of millions of years of evolution of OR proteins. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.