Semiconductor quantum dots for bioanalysis.
Semiconductor nanoparticles, or quantum dots (QDs), have unique photophysical properties, such as size-controlled fluorescence, have high fluorescence quantum yields, and stability against photobleaching. These properties enable the use of QDs as optical labels for the multiplexed analysis of immunocomplexes or DNA hybridization processes. Semiconductor QDs are also used to probe biocatalytic transformations. The time-dependent replication or telomerization of nucleic acids, the oxidation of phenol derivatives by tyrosinase, or the hydrolytic cleavage of peptides by proteases are probed by using fluorescence resonance energy transfer or photoinduced electron transfer. The photoexcitation of QD-biomolecule hybrids associated with electrodes enables the photoelectrochemical transduction of biorecognition events or biocatalytic transformations. Examples are the generation of photocurrents by duplex DNA assemblies bridging CdS NPs to electrodes, and by the formation of photocurrents as a result of biocatalyzed transformations. Semiconductor nanoparticles are also used as labels for the electrochemical detection of DNA or proteins: Semiconductor NPs functionalized with nucleic acids or proteins bind to biorecognition complexes, and the subsequent dissolution of the NPs allows the voltammetric detection of the related ions, and the tracing of the recognition events.
Gill
Ron
R
Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
Zayats
Maya
M
Willner
Itamar
I
D004247:DNA / Q000032:analysis*; D004563:Electrochemistry / Q000379:methods*; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry; D015335:Molecular Probes / Q000737:chemistry; D011506:Proteins / Q000032:analysis*; D045663:Quantum Dots; D012313:RNA / Q000032:analysis*; D012666:Semiconductors
D005456:Fluorescent Dyes; D015335:Molecular Probes; D011506:Proteins; D012313:RNA; D004247:DNA