Biomedical Engineering Reference
In-Depth Information
intracellular.organization.and.function.in.cell.signaling,.growth,.differentiation,.apoptosis,.
cell.developmental.processes,.and.relevant.diseases..Moreover,.in.biotechnology.industry,.
combinatorial. methods. are. increasingly. applied. to. synthesize. new. biocatalysts. or. drugs,.
demanding.simultaneous.analysis.of.thousands.of.pathogens,.mutants,.or.therapeutic.drugs..
Furthermore,.in.personalized.medicine,.as.dictated.by.economic.reasons,.mass.application.
of.screening.and.diagnostic.tools.has.to.be.fast,.convenient,.and.low.cost,.requiring.minia-
turization,.parallelization,.integration,.as.well.as.automation.of.biosensing.devices.
To. address. those. major. challenges. in. biosensing. research,. biosensors. based. on. plas-
mon-resonant.nanoparticle.bioconjugates,.so-called.plasmonic.nanobiosensors,
2
.are.being.
developed,.by.synergizing.three.core.techniques:.plasmonics.that.manipulates.electromag-
netic.radiation.(light).at.dielectric-metal.interfaces.by.tuning.properties.of.nanomaterials,.
nanofabrication,.and.controlled.synthesis.of.nanomaterials.containing.metals.(e.g.,.Au,.Ag,.
Pt,.and.Cu),.and.bioconjugate.techniques.that.modify.surface.of.nanomaterials.with.vari-
ous.bioreceptors.(e.g.,.antibodies,.enzymes,.aptamers,
3
.and.molecular.imprint.polymers
4
)..
Biomaterials.such.as.proteins,.DNA,.or.RNA.have.dimensions.of.2-20.nm,.similar.to.those.
of. plasmonic. nanostructures;. thus,. the. two. classes. of. materials. are. structurally. compat-
ible..Plasmonic.nanomaterials.exhibit.unique.electronic,.photonic,.and.catalytic.properties,.
providing. electronic. or. optical. transduction. of. biological. phenomena,. while. biomateri-
als. have. unique. recognition. and. catalytic. properties.. Their. integration. yields. plasmonic.
nanobiosensors.with.multiple.synergetic.advantages.over.traditional.molecular.imaging.
techniques:. sensitivity,. stability,. biocompatibility,. selectivity,. and. spectroscopic. imag-
ing.capability.
.
Furthermore,.recent.signiicant.advancements.in.controlled.synthesis.and.
nanofabrication,
5
.theory.and.electrodynamic.modeling.of.optical.properties,
6
.and.surface.
functionalization
7a
.of.plasmonic.nanomaterials.greatly.enhance.the.ability.to.control.and.
tune. the. unique. optical. and. electronic. properties. of. plasmonic. nanostructures. through.
their.sizes,.structures,.composition,.and.shapes,.building.libraries.of.probes.for.different.
analytes..Thus,.plasmonic.nanobiosensors.promise.a.great.potential.in.the.development.of.
high-throughput.techniques.for.the.parallel.analysis.of.multiple.components.in.samples.
These.recent.advancements.in.nanotechnology.and.nanoplasmonics.also.enable.hybrid.
plasmonic. nanostructures. as. subnanometer. and. nanometer. tools. to. directly. interface.
with.intracellular.processes..The.plasmonic.nanobiosensors.focus.electromagnetic.ields.
to.signiicantly.enhance.spectral.information.for.localized.surface.plasmon.spectroscopy.
(LSPR),
8
.surface-enhanced.Raman.spectroscopy.(SERS),
9
.plasmon.resonance.energy.trans-
fer.(PRET),
10
.and.integrated.photoacoustic-photothermal.contrast.agents.
11
.In.this.way,.we.
can. acquire. quantitative. spectral. snapshots. of. the. intracellular. biochemical. distribution.
over.time.as.a.result.of.local.microenvironmental.changes..In.this.review,.we.will.discuss.
nanoplasmonic. theory,.summarize.major.synthetic. and.nanofabrication.techniques,. and.
describe.surface.functionalization.of.plasmonic.nanobiosensors..We.will.then.exemplify.
the.applications.and.summarize.the.synergetic.relationships.among.three.core.techniques.
contained.in.plasmonic.nanobiosensing.to.address.the.major.aforementioned.challenges.
in.biosensing.research.
5.2 TheoreticalBackground
Nanophotonics. is. deined. as. “the. science. and. engineering. of. light. matter. interactions.
that. take. place. on. wavelength. and. subwavelength. scales. where. the. physical,. chemi-
cal,. or. structural. nature. of. natural. or. artiicial. nanostructured. matter. controls. the.
