Biomedical Engineering Reference
In-Depth Information
10
Receptor-Based Biosensors: Focus on
Olfactory
Receptors and Cell-Free Sensors
Nadine Hempel
CONTENTS
10.1. Introduction......................................................................................................................... 223
10.2. Biosensors............................................................................................................................ 224
10.3. Olfactory.G-Protein.Coupled.Receptors......................................................................... 224
10.3.1. GPCR.Signaling...................................................................................................... 224
10.3.2. Olfactory.Receptors................................................................................................ 225
10.3.3. OR.Biosensor.Applications................................................................................... 226
10.4. Immobilization.of.Receptors.onto.Biosensor.Surfaces.................................................. 229
10.4.1. Expression.and.Puriication.of.Recombinant.GPCRs....................................... 229
10.4.2. Immobilization.of.Lipid-Bilayers.and.
Membrane-Bound.Proteins.on.Sensor.Surfaces................................................ 230
10.5. Physical.Sensor.Platforms................................................................................................. 232
10.5.1. Field.Effect.Transistors.......................................................................................... 233
10.5.2. Surface.Plasmon.Resonance.................................................................................. 234
10.5.3. Acoustic.Wave.Sensors.......................................................................................... 234
10.6. Conclusions.and.Perspectives.......................................................................................... 235
References..................................................................................................................................... 237
10.1 Introduction
The.plasma.membrane.forms.an.important.sensory.interface.between.a.cell.and.its.extra-
cellular. environment.. This. phospholipid. bilayer. contains. a. heterogeneous. mix. of. lipids.
and.membrane-bound.proteins,.which.aid.in.transport.of.molecules.across.the.membrane.
and. facilitate. the. recognition,. transduction,. and. ampliication. of. extracellular. signals..
Biological.sensing.at.the.cell.membrane.starts.with.binding.of.an.extracellular.chemical.
ligand.to.its.complimentary.receptor..This.is.followed.by.transduction.of.the.binding.event.
into. a. cellular. signaling. cascade.. Receptor. engagement. may. result. in. a. conformational.
change. in. receptor. protein. structure,. binding. or. dissociation. of. accessory. proteins,. or.
phosphorylation.of.the.receptor.and/or.downstream.mediators..Second.messengers.facili-
tate. an. intracellular. signaling. cascade. that. cumulates. in. an. eventual. cellular. response..
Membrane.receptors.have.evolved.to.sense.a.vast.variety.of.endogenous.and.exogenous.
compounds. and. are. integral. in. key. cellular. processes. ranging. from. the. central. nervous.
system,.cardiac.function.to.sensory.systems,.such.as.smell.and.vision..Not.surprisingly,.
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