Optical and Electronic BiosensorsAn interdisciplinary Undergraduate Course

ECEDHA Regional Meeting Sept 14-16, 2012

Fil Bartoli

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NAE - Engineering’sGrand Challenges

1.Make solar energy economical2.Provide energy from fusion3.Provide access to clean water4.Reverse-engineer the brain5.Advance personalized learning6.Develop carbon sequestration

methods7.Restore/improve urban

infrastructure8.Engineer tools of scientific

discovery9.Advance health informatics10.Prevent nuclear terror11.Engineer better medicines12.Manage the nitrogen cycle13.Enhance virtual reality14.Secure cyberspace

Source: National Academy of Engineering

Appeal to Students

GOALS OF COURSE:• Introduce selected topics in optics, E&M, semiconductor

electronics and biology needed for optical and electronic biosensor research and development

• Emphasize exciting interdisciplinary opportunities at the intersection of photonics/optics, electronics, and nanotechnology with biomedicine and bioengineering

• Survey current trends in optical/electronic biosensors

• Provide an in-depth discussion of several biosensor systems at the forefront of biophotonics and bioelectronics

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Optical and Electronic Biosensors(Senior ECE Elective)

ECE students previously had Electromagnetics, Semiconductor Devices, and Signals and Systems, but not Biology (unlike BioEng students).

COURSE OUTLINE

• Review:• Optics, EM, semiconductor electronics and biology• Interaction of light with matter • Nanotechnology• Survey of current biosensors, principles of sensing

• Treat selected label-free biosensor systems in detail• Field-effect & High Electron Mobility Transistor biosensors • Exhaled breath biosensors • Nanopatterned Surface Plasmon Resonance biosensors• Biosensors for nerve cell synapse, synaptic plasticity

• Student projects and presentations

Recommended reading: Essential Cell Biology (Alberts, et al.), Selected Papers from the Scientific Literature

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Topics to Cover

Electromagnetics• Propagation of EM waves incident on interface between two

dielectrics or a dielectric and a metal• Evanescent fields• Surface Plasmons• Optical interference

Semiconductor device physics• Field-effect transistors• Quantum-well devices• Mid-IR Semiconductor lasers (type-II, QCL, resonant tunneling)• Infrared detection

Optical spectroscopy• Molecular vibrational absorption• Mid-IR laser detection of species in weakly absorption gases• Resonant optical cavities• Photoacoustic spectroscopy, QEPAS

Bioengineering – affinity recognition, cellular processesLehighUniversityLehighUniversity

Some Biomolecular Length Scales

Nanotechnology is an important driver.

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Biosensing Instrument Inc. © 2006

Surface Plasmon Resonance

Metal-dielectric interface

surface plasmons

For a metal,

Example:

For λ = 700 nm, ω = 2.69 x 1015,εgold = -16, εwater = 1.77, penetration depth (1/k) = 238 nm.

DISPERSION RELATIONS (ω-k):

Biacore Flexchip SPR Microarray

Period: 300nm 450nm 550nm Diam: 155nm 180nm 225nm

W.L. Barnes, A. Dereux and T.W. Ebbesen, Nature 424, 824 (2003).

Nanoplasmonic structures for biosensing

Optical FilteringExtraordinary optical transmission

Scanning electron micrograph of nanoplasmonic “crystal”LehighUniversityLehighUniversity

P. Petrou, Institute of Radioisotopes & Radiodiagnostic Products, Greece

Biotin:

Member of Vitamin B family (Vitamin B7 or H).

An essential nutrient in human nutrition.

Avidin: Large protein with 4 identical subunits – can bind to 4 biotin molecules

Highly favorable physical properties

BioreceptorsBiotin-Avidin (Streptavidin)

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2DEG

Field-effect and High Electron Mobility Transistors

2-dimensional electron gas (2-DEG) at AlGaN/GaN junction• Polarization produces 2DEG due to crystal lattice strain (AlGaN/GaN lattice mismatch), and spontaneous polarization. • Positively-ionized surface interacts with analytes, changes the 2DEG charge distribution, and changes channel conductance.

HEMT physics differs from silicon MOSFET physics.

Schematic structure of an ImmunoFET with immobilized antibody(Ab) antibody molecules. Ag, antigen molecules.

Debye Screening Length in electrolyte

For physiologically relevant concentrations 150-160 mM (salt in blood or serum), Debye length < 1nm (continuing challenge).

Analyst, 2002, 127, 1137–1151Schöning,

Ekips Technologies

Exhaled Breath Biosensors

• Infrared vibrational absorption of exhaled breath gases

• Medical implications

• Gas collection

• Mid-IR Laser sources

• IR detection schemes

Exhaled breath biosensors

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Exhaled breath biosensors

Exhaled breath biosensors

Diode Laser Absorption Spectroscopy; Photoacoustic Spectroscopy• Molecules uniquely identified by mid-IR

absorption• Strong resonance lines - ppt (parts-per-

trillion) sensitivity

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Quantum Mechanics Review

FIVE EASY PIECES:

Particles or Waves???Schrodinger Wave EquationWe are dealing with probabilitiesParticle in a box (Quantum Well)Tunneling through a Barrier

NOT SO EASY PIECES: (LATER!)

Type-1 vs. Type-2 Quantum WellWhat is a Quantum Cascade Laser

Mid-IR Laser sources

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• Optical Coherence Tomography (Travis Kelly, Pat Knowles)

• Two-Photon Microscopy (Sean Kennedy, Craig Ungaro)

• DNA Microarrays (Mike Casella, Matt Cowperthwait)

• Pulse Oximeters (Eileen Mazzochette, Tim Syciarz)

• Nanopatterned Surface Plasmon Resonance Biosensors (Yongkang Gao, Kangbaek Kim)

• Noninvasive Optical Sensing of Blood Analytes (Rick Arlow, Sam Wechsler)

• Waveguide and Microresonator Biosensors (Stephen Paro, Brad Riddle)

Student Team Projects

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Optical and Electronic Biosensors

Thank You!

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PROVIDES:

• Interdisciplinary Educational Experience• Team-based project learning• Gives students practice reading scientific literature• Integration of Research and Education