Biosensor Based on Carbon Nanotube Field Effect

8/2/2019 Biosensor Based on Carbon Nanotube Field Effect

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Instituto Politcnico NacionalUnidad Profesional Interdisciplinaria de Biotecnologa

IBT. Irving Flores Avils


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The irruption of nanotechnology inscience health has led to a newdiscipline called nanomedicine,which aims is the development oftools for diagnose, prevent and

treat diseases when states are stillin some advanced or at thebeginning of its development.Nanomedicine is committed tostudying interactions at thenanoscale and it uses devices,

systems and technologies thatinclude nanostructures capable ofinteracting at molecular level andwhich are interconnected at microscale to interact at the cellular level.


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Nanomedicine brings together three mainareas:

NANODIAGNOSIS REGENERATIVE MEDICINENANOTHERAPY


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The goal is theidentification ofnanodiagnosis disease inits early stages in thecellular or molecular leveland, ideally, the level of asingle cell, through theuse nanodevices and

contrast systems. Within the nanodiagnosis,there are two main areasof work: nanosystemsImage and

nanobiosensors,


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Developments withinnanobiosensors are tohighlight the

nanobiosensorsphotonic SPR basedon nanostructures(Nanoparticles,carbon nanotubes,nanowires,etc..) andnanomechanicalbiosensors.


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In the fight againstcancer, half the battleis won based on early

detection.Nanotechnology iscontributing newmolecular agents andmethods to enableearlier and moreaccurate diagnosis andtreatment monitoring

Researchers at the Nanosystems Biology Cancer Center at Caltech have developed a microchip capable of quickly detecting cancer biomarkers from a drop of blood. The

microchip separates the plasma from the blood and when cancer biomarkers are present, they light up as barcode stripes as shown in the background of the image above. Thesedisease barcodes could eventually be scanned using a barcode scanner, similar to the ones used at the supermarket, to give accurate point-of-care diagnoses.IOphir Vermesh; Rong Fan, Ph.D.; and James R. Heath, Ph.D.


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Cancer remains one of the most complex diseases affectinghumans and, despite the impressive advances that have beenmade in molecular and cell biology, how cancer cells progressthrough carcinogenesis and acquire their metastatic ability is stillwidely debated

Today, cancer is recognized as a highly heterogeneous disease andover 100 distinct types have been described with various tumorsubtypes found within specific organs. It is now also recognizedthat genetic and phenotypical variability primarily determines theself-progressive growth, invasiveness, and metastatic potential ofneoplastic disease and its response or resistance to therapy. Itseems that this multi-level complexity of cancer explains theclinical diversity of histologically similar neoplasias.


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To help meet the goal of eliminating death and suffering fromcancer by 2015, the National Cancer Institute is engaged in acancer nanotechnology plan which has six major challenge areasof emphasis:

Prevention and Control of Cancer

Early Detection and Proteomics

Imaging Diagnostics

Multifunctional Therapeutics

Quality of Life Enhancement in Cancer Care

Interdisciplinary Training


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NANOTECHNOLOGY AND DIAGNOSIS:

Prevention and Control of Cancer

-Developing nanoscale devices that can deliver cancer prevention agents

-Designing multicomponent anticancer vaccines using nanoscale deliveryvehicles

Early Detection and Proteomics

-Creating implantable, biofouling-indifferent molecular sensors that can detectcancer-associated biomarkers that can be collected for ex vivo analysis or

analyzed in situ, with the results being transmitted via wireless technology to thephysician

-Developing smart collection platforms for simultaneous mass spectroscopicanalysis of multiple cancer-associated markers


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A Biomarker is a biological molecule foundin blood, other body fluids, or tissues thatis a sign of a normal or abnormal process orof a condition or disease. Biomarkers canbe of various molecular origins, including

DNA (ie, specific mutation, translocation,amplification, and loss of heterozygosity),RNA, or protein (ie, hormone, antibody,oncogene, or tumor suppressor). Cancerbiomarkers are potentially one of the mostvaluable tools for early cancer detection,accurate pretreatment staging,determining the response of cancer tochemotherapy treatment, and monitoringdisease progression.


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EARLYDETECTION

OF CANCER

NANOBIOSENSORS CANCERBIOMARKERS


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Main objective

The development of a electrochemicalbiosensor, using the CNTs as the transducerelements and a antigen-antibody interactionas the molecular recognition mechanism ofthe proposed cancer biomarker IGFBP-2 inthe early stage of HCC.


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Specific Objectives

-Functionalise the designed device with specificmolecular recognition able to selectively detect theproposed cancer biomarker.

-Explore the capability of CNTFET to reach selectivityand sensivity comparable to current detectionmethods of protein biomarkers.

-Diagnostic trials at differente concentrations of thetarget cancer biomarker


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JUSTIFICATION

The application of CNTFET for validation ofIGFBP-2 as a secreted protein associated withthe progression of liver cancer will acompearly diagnosis of HCC


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EXPERIMENTAL STRATEGIES

PHASEI-BACKGROUND SYNTHESIS OF CARBON

NANOTUBES

CNTFETs DESIGN

RECOGNITIONELEMENTS

DETECTION ELEMENTS

INMOBILIZATIONMETHODS

PHASEII-DEVELOPMENTOF

THECNTFETs

PREVIOUSCHARACTERIZATION

NON-SPECIFICADSORPTION

BINDING THROUGH

SPECIFIC ADSORPTION.

CHARACTERIZATION OFTHE BIO-CNTFET.

BIOMOLECULARINTERACTIONSVALIDATION

RESULTS.PRESENTATION. P

HASEIII-CANCERBIOMARKER

DETECTION

EXPERIMANTAL

DATACOMPARISSION

REAL SAMPLES


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PHASE I-SYNTHESIS OF NANOTUBES.

TOP SECRET.


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CNTFETs DESIGNSECOND TYPE: BASED ON A NETWORK OF CNTs P-TYPE BEHAVIOUR

PHASE I


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CNTFETs DESIGN

PHASE I


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RECOGNITION ELEMENTS:IGFBP-2 specific IgG antibody

PHASE I


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RECOGNITION ELEMENTS:IGF-II antibody complex (DX-2647)

PHASE I

CHAIN D: INSULINGROWTH FACTOR II

CHAIN H:ANTIBODY-FAB(HEAVY CHAIN)

CHAIN L:ANTIBODY-FAB(LIGHT CHAIN)

DX-2647, a human monoclonalantibody against insulin-like growth

factor-II blocks the growth of humanhepatocellular carcinoma cell lines invitro and in vivo.


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RECOGNITION ELEMENTS:

Protein G from Streptococcus sp.

PHASE I




Protein G consists in 56 residues thatfolds into four stranded s-sheet andone -helix.

Genetically engineered truncatedprotein G, which retains its affinity forIgG, but which lacks albumin- andFab-binding sites and membrane-binding regions


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DETECTION ELEMENTS:IGFBP-2

PHASE I




Inhibits IGF-mediated growth anddevelopmental rates. IGF-binding proteinsprolong the half-life of the IGFs and havebeen shown to either inhibit or stimulatethe growth promoting effects of the IGFson cell culture. They alter the interactionof IGFs with their cell surface receptors

PROPOSED CANCER BIOMARKER.


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DETECTION ELEMENTS:IGF-2

PHASE I




Elevated expression of insulin-like growthfactor-II (IGF-II) is frequently observed in avariety of human malignancies, includingbreast, colon, and liver cancer. As IGF-II candeliver a mitogenic signal through both IGF-

IR and an alternately spliced form of theinsulin receptor (IR-A), neutralizing thebiological activity of this growth factordirectly is a potential alternative option toIGF-IR-directed agents.

PROPOSED CANCER BIOMARKER.


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INMOBILIZATION METHODS:NON- ESPECIFIC ADSOPRTION

PHASE I



ANTIBODY-FAB(LIGHT CHAIN)

The direct adsorption of immunoglobulin on asurface is a non-covalent process governedmainly por hydrophobic interactions betweenthe antibodiesand the solid surface.

IGFBP-2 specific IgG antibodyIGF-II antibody complex (DX-2647)


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INMOBILIZATION METHODS:BINDING THROUGH THE PROTEIN G

PHASE I




IGFBP-2specific IgG

antibodyIGF-II antibodycomplex (DX-

2647)

In order to obtain well-orientated antibodioslinked to the SWCNTsurface, bacterial

proteins like Protein Gcan be used whichdisplay high especificityfor the Fc domain of theIgG, thus leaving the Fabregion avaible fordetecting the target.


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INMOBILIZATION METHODS:BINDING THROUGH THE PROTEIN G

PHASE I


CHAIN H:ANTIBODY-FAB(HEAVY CHAIN)Chain C and D:

Streptococcalprotein G (c2fragment)

Streptococcal protein Gcomprises two or threedomains that bind to theconstant Fc region of mostmammalian

immunoglobulin Gs (IgGs).Protein G is functionallyrelated to staphylococcalprotein A, with which itshares neither sequence norstructural homology.

Chain A and B:IgG Fc Domain.


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INMOBILIZATION METHOD:ESPECIFIC ADSORPTION

PHASE I




Microwave-assistedfunctionalization

method.


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INMOBILIZATION METHOD:ESPECIFIC ADSORPTION

PHASE I




CRYSTAL STRUCTURE OF THE RABBIT IGG FC FRAGMENT


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PREVIOUS CHARACTERIZATION:SPECTROSCOPIC ELLIPSOMETRY CHARACTERIZATION

PHASE II




Characteriza a pure wafer ofSi/SiO2 and wafer containing the

as-grown network ofCNTsbefore starting thebiofuncionalization.


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PREVIOUS CHARACTERIZATION:AFM CHARACTERIZATION

PHASE II




AFM is a well known techniquethat provides direct images of thesurface topography with outspecial pre-treatment. Thistecnique allows us yo mesure theheight of the CNTs. In this way, itis possible to verify that thesysthesized CNTs are indeedsingle-walled carbon nanotubes.


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PREVIOUS CHARACTERIZATION:ELECTRICAL CHARACTERIZATION

PHASE II




The electrical characterization is

performed as follos:

Apply a source-to-drain sweep voltaje(Vsd) (+250 mV to -250 mV) keeping

constant the gate voltaje (Vg) at OV

which allow us to obtain the

resistance of the channel, the

optimum value of Vsd and the source

to gate current. Register theelectrical current while sweeping the

Vg. Generating a curve that is also

registered after each funcionalisation

setp


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BIO-CNTFET CHARACTERIZATION:SPECTROSCOPIC ELLIPSOMETRY CHARACTERIZATION

PHASE II





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BIO-CNTFET CHARACTERIZATION:AFM CHARACTERIZATION

PHASE II





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BIOMOLECULAR INTERACTIONS VALIDATION

PHASE II




One of the main uses of QCM-D is for studyingadsorption/ desorption onto solid surfaces.


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BIOMOLECULAR INTERACTIONS VALIDATION

PHASE II





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RESULTS AND DISCUSSION

PHASE II





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PHASE III




PHASEIII-CANCERB

IOMARKER

DETECTIONINREALSAMPLES.

EXPERIMANTAL

DATACOMPARISSION

REAL SAMPLES


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REFERENCES




Documents

Biosensor Based on Carbon Nanotube Field Effect