Rapid detection and identification of bacteria with graphene field effect transistors and peptide probes
A method and system for label-free detection of pathogenic and antibiotic resistant bacteria is disclosed. The method includes fabricating a G-FET/peptide device having a synthesized peptide probe capable of recognizing and binding to a bacterial target; performing electric-field assisted binding of at least one bacterial cell of the bacterial target to the G-FET/peptide device; and electrically detecting the binding of the at least one bacterial cell to the G-FET/peptide device.
1. A label-free bacteria detection system, comprising:
a graphene field effect transistor (G-FET)/peptide device capable of biosensing using dielectrophoresis and comprising a peptide probe formed of a chemically modified peptide conjugated to a flat aromatic linker and capable of recognizing and binding to a bacterial target integrated on the G-FET, wherein the G-FET comprises a defect-free graphene monolayer fabricated into a field effect transistor having electrical contacts insulated from a defined sensing area.
2. The device of claim 1 , wherein the bacterial target is pathogenic bacteria.
3. The device of claim 1 , wherein the bacterial target is an antibiotic resistant bacterial strain.
4. The device of claim 1 , wherein the peptide probe is bacterial species specific.
5. The device of claim 1 , wherein the peptide probe is bacterial strain specific.
6. The device of claim 1 , wherein the G-FET/peptide device is stable at room temperature.
7. The device of claim 1 , wherein the bacterial target includes S. aureus (ATCC 6538), wild-type A. baumannii (AB5075), A. baumannii (5075 LOS-), B. subtilis , or E. coli.
8. A method for the label-free detection of bacteria, comprising:
fabricating a defect-free graphene monolayer into a graphene field effect transistor (G-FET) having electrical contacts insulated from a defined sensing area;
synthesizing a chemically modified peptide and conjugating the synthesized peptide to a flat aromatic linker to create a peptide probe capable of recognizing and binding to a bacterial target;
integrating the peptide probe on the G-FET to provide a G-FET/peptide device capable of biosensing using dielectrophoresis;
performing electric-field assisted binding of at least one bacterial cell of the bacterial target to the defined sensing area of the G-FET/peptide device; and
electrically detecting the binding of the at least one bacterial cell to the G-FET/peptide device.
9. The method of claim 8 , wherein electrically detecting the binding of the at least one bacterial cell comprises monitoring changes in the Dirac voltage.
10. The method of claim 8 , wherein the at least one bacterial cell is pathogenic bacteria.
11. The method of claim 8 , wherein the at least one bacterial cell is an antibiotic resistant bacterial strain.
12. The method of claim 8 , wherein the peptide probe is bacterial species specific.
13. The method of claim 8 , wherein the peptide probe is bacterial strain specific.
14. The method of claim 8 , wherein the G-FET/peptide device is stable at room temperature.
15. The method of claim 8 , wherein the at least one bacterial cell includes S. aureus (ATCC 6538), wild-type A. baumannii (AB5075), A. baumannii (5075 LOS-), B. subtilis , or E. coli.
16. The method of claim 8 , wherein the method has a sensitivity including a detection limit to 10 4 cells/ml and detection time to below 5 minutes.
17. The method of claim 8 , wherein electrically detecting the binding of the at least one bacterial cell includes determining the concentration of the at least one bacterial cell bound to the G-FET/peptide device.
18. The method of claim 8 , further comprising:
wherein integrating the peptide probe on the G-FET comprises a single-step attachment of the linker molecule peptide probe to the G-FET.