Nanotechnology for point of care diagnostics. Shana O. Kelley University of Toronto

Transcription

1 Nanotechnology for point of care diagnostics Shana O. Kelley University of Toronto

2 Nanotechnology what is it and why is it relevant to medicine? Existing molecular diagnostic technologies strengths and weaknesses Development of a nanotechnology-enabledenabled platform for biomarker detection Application of platform in infectious disease

3 Working at the nanoscale Head of a pin: 1,000,000 nm Human hair: 60,000 nm DNA: 2 nm

4 Nanotechnology for biology and medicine Semiconductor quantum dots (2-20 nm) Medical imaging Nanowires (2-20 nm x nm) Biosensing Metallic nanoparticles (2-20 nm) Biosensing Therapeutics Carbon nanotubes (2-20 nm x nm) Biosensing Drug delivery Polymer nanoparticles ( nm) Drug delivery

5 Nanotechnology for biology and medicine nanomaterials Biomolecules/disease biomarkers Biomolecules are nanoscale Nanomaterials have dimensions on right size scale for sensitive detection of their presence From Weiss et al, Science (2005) 307, 539.

6 Development of new nanobiosensors and bioelectronics Kelley research group: University of Toronto Detection of DNA, RNA, protein analytes Identification of diseased cells

7 Diagnostics used for infectious disease diagnosis PCR Faster, but expensive Culture cheap & accurate but slow heat cool X M Becton Dickinson/Cepheid Leaders in MDx for infectious disease

8 Chip-based diagnostics for infectious disease diagnosis The goal: create a highly accurate, highly sensitive chip-based platform for inexpensive testing Low-cost Highly sensitive Multiplexed Standardized Small footprint/handheld Low power requirements Automated sample processing

9 SK1 Electronic/electrochemical sensors Glucose + glucose oxidase electrical current Compactness and simplicity of electrochemical sensors = low cost Free sensing units distributed to patient, pay for consumables

10 Slide 9 SK1 My resaerch group at U. Toronto Shana Kelley, 27/10/2008

11 Electronic/electrochemical DNA & RNA sensors reporter group target DNA/RNA sequence Immobilized probe sequence e - Electrical and electrochemical readout

12 Design of a nanomaterialsnanomaterials-based platform for biomolecular detection 500 nm opening in SiO2 Gold lead (5 µ) electroless deposition Collaboration with Prof. Ted Sargent, U. Toronto (ECE) electrodeposition Nanostructured microelectrode (NME)

13 Nanoscale sensing elements Feature size 100 nm 4 µm Feature size 5000 nm Feature size 20 nm L. Soleymani, Z. Fang, E.H. Sargent, S.O. Kelley, Nature Nanotechnology, 2009, in press, DOI: /nnano

14 Nanoscale sensing elements

15 Nanoscale sensing elements + RNA - RNA As few as 100 molecules detected on-chip Proof-of-principle applications Prostate cancer biomarker analysis (Fang et al, ACS Nano, 2009) Micro RNA expression profiling (Yang et al, Angew. Chem., 2009)

16 Sensitivity controlled by nanostructuring of sensing elements 1 um 2 um 200 nm Limit of detection: 100,000,000 molecules Limit of detection: 1,000,000 molecules Limit of detection: 100 molecules L. Soleymani, Z. Fang, E.H. Sargent, S.O. Kelley, Nature Nanotechnology, 2009, in press, DOI: /nnano

17 Next steps: instrument development USB/battery-powered chip reader software interface microfluidic sample handling

18 Design of specific probes for TB detection Several mycobacteriumspecific regions have been identified M: intra-species variable region M ( ) A-E: primarily inter-species variable regions A ( ) B ( ) C ( ) D ( ) E ( ) EarI SmlI XhoI MslI PmlI NsiI Ppu10I Eco47III HaeII NaeI NgoMIV BtsI SspI Ecl136II PshAI SnaBI AccIII BsiHKAI SacI BsiEI Eco52I ScaI PstI SfcI ApoI EcoRI BsmI FspI EcoRV SgrAI AgeI AlwNI BbvCI BseRI EcoO109I ApaI BamHI XhoII BseSI PspOMI M A BC D E EciI VspI MluI XbaI BspMI BstAPI HincII AatII AhdI TfiI XmnI SmaI XmaI BsrGI BtrI BspHI Tth111I Also: devr, IS6110

19 Detection of antibiotic-resistant bacteria

20 Summary: Chip-based diagnostics for infectious disease A microchip platform with very high sensitivity has been developed low cost of fabrication makes technology suitable for patient screening A handheld chip reader is under development for testing in resource-limited settings A fully automated, rapid screening test for TB testing is one of the applications under development

21 Acknowledgments Kelley group Chip-based diagnostics Zhichao Fang Leyla Soleymani Van Tram Lisa Vasilveya Hooman Zamani Dr. Hong Yang Dr. George Pampalakis Dr. Heather Lord Collaborators Dr. Jeremy Squire (Queen s) Dr. Ted Sargent (U of T) Dr. Fei-Fei Liu (PMH) Financial Support OICR CIHR NSERC Prostate Cancer Foundation of Canada Genome Canada Ontario Centres of Excellence