Presentation Information
[P01-113]Development of odor sensors using an olfactory receptor-derived peptide library
○Mina Okochi1 (1. Institute of Science Tokyo (Japan))
Keywords:
Peptides,Olfactory receptors,FET,Odor sensor
[Purpose]
The development of ultra-sensitive odor sensors that detect volatile organic compounds is expected to have a wide range of applications, including environmental monitoring, hazardous materials detection and quarantine, manufacturing flow and quality control, and health and disease monitoring. Existing large-scale analyzers, such as gas chromatography, are capable of high-precision detection, but they have some issues, such as complicated operation, and real-time and on-site detection. Therefore, the development of miniaturized odor sensors, such as using the graphene field-effect transistors (GFETs), has been widely and vigorously pursued. The FETs are capable of detecting charge changes in the extreme vicinity of the channel surface in the Debye length. Consequently, there is a problem of reduced sensitivity when using the recognition molecules, such as antibodies and receptors, that have excellent sensitivity and specificity in their interactions with target odorant molecules due to the Debye shielding effect. To address these issues, this study aimed to design peptide probes for sensing volatile organic compounds and to develop ultra-sensitive sensing technology by constructing GFET peptide interfaces.
[Method]
A peptide library was designed from the amino acid sequences of olfactory receptors and spot-synthesized on a cellulose membrane using the automated peptide synthesizer. The peptide array was immersed in a 10 mM phosphate buffer with the addition of the target odorant, and after washing, the amount of bound odorant was measured using GC/MS. The selected odorant-binding peptide was bi-functionalized via conjugation with the graphene-binding peptide to enable a graphene functionalization via self-assembly. The GFET sensing was performed by measuring the change in drain current with a gate voltage of 350 mV and a drain voltage of 5 mV at 0.5 s intervals.
[Results and Consideration]
The affinity of each peptide was evaluated through a series of binding assays with various concentrations of the target odorant. Also, the peptide selectivity was evaluated in a competitive binding assay. The modification of a bi-functionalized peptide on GFET was confirmed using the atomic force microscope after peptide incubation. Also, a negative shift in the Dirac point voltage of the peptide-functionalized GFET was observed by the electrostatic gating effect from a positively charged peptide self-assembling on the graphene. In the GFET odor sensing, ultra-sensitive detection with a pico-molar level detection limit, with excellent repeatability and selectivity.
[Conclusion]
The olfactory receptor-derived peptide probes worked effectively for odorant GFET sensing. This research contributes to the development of olfactory mimetic sensors and highlights the potential of peptide libraries as molecular recognition probes for detection applications.
The development of ultra-sensitive odor sensors that detect volatile organic compounds is expected to have a wide range of applications, including environmental monitoring, hazardous materials detection and quarantine, manufacturing flow and quality control, and health and disease monitoring. Existing large-scale analyzers, such as gas chromatography, are capable of high-precision detection, but they have some issues, such as complicated operation, and real-time and on-site detection. Therefore, the development of miniaturized odor sensors, such as using the graphene field-effect transistors (GFETs), has been widely and vigorously pursued. The FETs are capable of detecting charge changes in the extreme vicinity of the channel surface in the Debye length. Consequently, there is a problem of reduced sensitivity when using the recognition molecules, such as antibodies and receptors, that have excellent sensitivity and specificity in their interactions with target odorant molecules due to the Debye shielding effect. To address these issues, this study aimed to design peptide probes for sensing volatile organic compounds and to develop ultra-sensitive sensing technology by constructing GFET peptide interfaces.
[Method]
A peptide library was designed from the amino acid sequences of olfactory receptors and spot-synthesized on a cellulose membrane using the automated peptide synthesizer. The peptide array was immersed in a 10 mM phosphate buffer with the addition of the target odorant, and after washing, the amount of bound odorant was measured using GC/MS. The selected odorant-binding peptide was bi-functionalized via conjugation with the graphene-binding peptide to enable a graphene functionalization via self-assembly. The GFET sensing was performed by measuring the change in drain current with a gate voltage of 350 mV and a drain voltage of 5 mV at 0.5 s intervals.
[Results and Consideration]
The affinity of each peptide was evaluated through a series of binding assays with various concentrations of the target odorant. Also, the peptide selectivity was evaluated in a competitive binding assay. The modification of a bi-functionalized peptide on GFET was confirmed using the atomic force microscope after peptide incubation. Also, a negative shift in the Dirac point voltage of the peptide-functionalized GFET was observed by the electrostatic gating effect from a positively charged peptide self-assembling on the graphene. In the GFET odor sensing, ultra-sensitive detection with a pico-molar level detection limit, with excellent repeatability and selectivity.
[Conclusion]
The olfactory receptor-derived peptide probes worked effectively for odorant GFET sensing. This research contributes to the development of olfactory mimetic sensors and highlights the potential of peptide libraries as molecular recognition probes for detection applications.
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