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Introduction to Introduction to BiosensorsBiosensors

Prof. Xingwei WangProf. Xingwei Wang

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Brain StormBrain Storm

What do you think of biosensor?What do you think of biosensor?

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Brain StormBrain Storm

What do you think of biosensor?What do you think of biosensor?

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Significance & Great DemandsSignificance & Great Demands

Food safety

Public Health Pathology

Criminology

Civil defense

Environmental Monitoring

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Brief HistoryBrief History 1956, Prof. Clark, Father of biosensor concept, Invention of the oxygen 1956, Prof. Clark, Father of biosensor concept, Invention of the oxygen

electrodeelectrode 1962, First description of a biosensor1962, First description of a biosensor 1972/5, First commercial biosensor: Yellow Springs Instruments glucose 1972/5, First commercial biosensor: Yellow Springs Instruments glucose

biosensorbiosensor 1975, First immunosensor1975, First immunosensor 1980, First fibre optic pH sensor for 1980, First fibre optic pH sensor for in vivoin vivo blood gases blood gases 1983, First surface plasmon resonance (SPR) immunosensor1983, First surface plasmon resonance (SPR) immunosensor 1987, Launch of the MediSense ExacTech™ blood glucose biosensor1987, Launch of the MediSense ExacTech™ blood glucose biosensor 1990, Launch of the Pharmacia BIACore SPR-based biosensor system1990, Launch of the Pharmacia BIACore SPR-based biosensor system 1992, i-STAT launches hand-held blood analyser1992, i-STAT launches hand-held blood analyser 1996, Abbott acquires MediSense for $867 million1996, Abbott acquires MediSense for $867 million 1998, Launch of LifeScan FastTake blood glucose biosensor1998, Launch of LifeScan FastTake blood glucose biosensor 1998, Merger of Roche and Boehringer Mannheim to form Roche 1998, Merger of Roche and Boehringer Mannheim to form Roche

DiagnosticsDiagnostics 2001, LifeScan purchases Inverness Medical's glucose testing business for 2001, LifeScan purchases Inverness Medical's glucose testing business for

$1.3billion$1.3billion

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What is a BiosensorWhat is a Biosensor

A device that uses biological components e.g. A device that uses biological components e.g. enzymes to indicate the amount of a enzymes to indicate the amount of a biomaterialbiomaterial

Trace biomaterial?

– Unnecessary (Eg. Metal ion, etc.)

Quantitative results?

– Unnecessary (Eg., Pregnancy test)

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ComponentsComponents

Bio Recognition Element

Enzymes; Antibodies; Receptors; Whole cells...

Electrochemical

Optical

Transducer

Signal Output

Requires: Sample Immobilization

Requires:Simple read out and data interpretation;Easy to use;Quick response.

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Performance FactorsPerformance Factors

Sensitivity: Concentration; weightSensitivity: Concentration; weight Specificity/Selectivity: discriminate between Specificity/Selectivity: discriminate between

substratessubstrates Speed: Bench->Chip->Real TimeSpeed: Bench->Chip->Real Time Accuracy: False signalAccuracy: False signal CostCost Easy to useEasy to use Life timeLife time

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Biosensing for MacromoleculesBiosensing for Macromolecules

Steps:Steps: ImmobilizationImmobilization MixingMixing Washing the non-specific bindingsWashing the non-specific bindings Signal transductionSignal transduction

Markers:Markers: EnzymesEnzymes Fluorescence tagsFluorescence tags Radioactive tagsRadioactive tags

Molecular:Molecular: Waston-Crick Base Waston-Crick Base

pairingpairing Antibody-Antigen Antibody-Antigen

bindingbinding

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ImmunosensorImmunosensor

Antibody can be againstAntibody can be against BacteriaBacteria Complex carbohydratesComplex carbohydrates Smaller organic moleculesSmaller organic molecules

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DNA Complementary ChainsDNA Complementary Chains

Four nitrogen basesFour nitrogen bases Complementary chainsComplementary chains

C

G

A

T

C G

A T

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Six StepsSix Steps1)1) Select the single-stranded capture DNA sequenceSelect the single-stranded capture DNA sequence

2)2) Attach the capture DNA strand to a probeAttach the capture DNA strand to a probe

3)3) Introduce the samples to be identified to the probesIntroduce the samples to be identified to the probes

4)4) Hybridization will occur if the sample is Hybridization will occur if the sample is complementary with the capture sequence on the complementary with the capture sequence on the probeprobe

5)5) Wash away the remaining unattached samplesWash away the remaining unattached samples

6)6) JudgmentJudgment

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TransducerTransducer

Electrochemical (Potentiometric, Electrochemical (Potentiometric, Voltammetric, Amperometry, Conductimetric)Voltammetric, Amperometry, Conductimetric)

Optical (Fluorescence, Absorbance, Light Optical (Fluorescence, Absorbance, Light scattering, Refractive index)scattering, Refractive index)

Mechanical, Thermal, Piezoelectric, MagneticMechanical, Thermal, Piezoelectric, Magnetic

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Glucose SensorGlucose Sensor

http://www.ul.ie/elements/Issue6/Biosensors-%20Elements.htm

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MicrocantileversMicrocantilevers

From http://www.ornl.gov/info/ornlreview/rev29_3/text/biosens.htm

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Medical TelesensorMedical Telesensor

From http://www.ornl.gov/info/ornlreview/rev29_3/text/biosens.htm

• Military: Locate wounded soldiers•Domestic: Intensive patients

• An array of chips to monitor body functions•Wireless transmission

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Broad Potential ApplicationsBroad Potential Applications

(Picture from www.primordial.com/.../Hardware_Soldier_w640.png)

Warfighter Physiological Status Monitoring (WPSM): remote triage of injured SoldiersHeart rate, breaths taken, skin temperature and ballistic impactFoster-Miller (Waltham, Mass.) Putting these sensors on a belt that's sewn into a shirt

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BenefitsBenefits

Industry Military

Academia

Biosensor

2020

Challenges and TrendChallenges and Trend

CostCost SensitivitySensitivity SelectivitySelectivity SpeedSpeed Small?Small? Ease to use?Ease to use?

CheapCheap SensitiveSensitive SelectiveSelective SpeedSpeed PortablePortable SimpleSimple IntegratedIntegrated Mass producedMass produced Multiple analytesMultiple analytes

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Multidisciplinary NatureMultidisciplinary Nature

Biosensor Chemistry

Biology

PhysicsInstrumentation

Electronics

Optics

Market

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Worldwide Biosensor Vendor Market, Worldwide Biosensor Vendor Market, 20032003