Integrated NanoparticleBiomolecule Hybrid Systems: Synthesis, Properties, and Applications

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Integrated NanoparticleBiomolecule Hybrid
SystemsSynthesis, Properties, and Applications

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• C2007

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From the contents

• Introduction
• Synthesis and properties of Biomolecule-Functional
  ized Nanoparticles
• Bimolecule-Functionalized Nanoparticles for
  Controlled Chemical Reactivity
• The Aggregation of Bimolecule-Functionalized
  Nanoparticles
• Assembly of Bimolecule-Nanoparticle Architectures
  on Surfaces
• Bimolecule-Based Nanocircuitry
• Conclusions

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Nanobiotechnology

• Combination of nanoobjects,
• nanotools, and nanotemplates
• with biomolecules yields new
• facets of bioelectronics to open
• new horizons of nanobioelectronics.
• Herein, we aim to review the
• synthesis and properties of
• biomoleculenanoparticle/nanorod
• hybrid systems as well as
• the organization of these systems
• as functional devices.

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Functionalized of Nanoparticles with Biomolecules
Through Electrostatic Adsorption

• The simple adsorption of
• biomolecules on NPs has
• frequently been performed
• and studied for biomolecules,
• which range from low-
• molecular-weight organic
• substances e.g. vitamin C)
• to large (protein/enzyme
• molecules.) NPs that are stabilized
• by anionic ligands such as
• carboxylic acid derivatives (citrate,
• tartrate,lipoicacid), theadsorption
• of positively charged proteins
• originates from electrostatic
• Interactions.
• .

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CdS NP-capped mesoporous silica nanosphere
(MSN)-basedsystem for the controlled delivery of
drugs andneurotransmitters

• Functionalized CdS NPs were
• used to entrap drugs or
• neurotransmitters in the
• channels (average diameter
• 2.3 nm) of MCM-41-type
• mesoporous silica nanospheres
• (MSNs) in a configuration
• that enabled the controlled
• releaseof the entrapped
• Substances.

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Receptor-Induced Aggregation of
Guest-FunctionalizedNanoparticles

• Au NPs functionalized with
• adsorbed biotin units and
• then cross-linked with SAv
• units have been shown to
• yield aggregates of Au NPs
• with the biotinSAv recognition
• pairs between the individual NPs .
• A similar architecture can be built
• by reversing the steps SAv was
• interacted with the biotin
• disulfide derivative 13 to produce
• a complex, which was then
• treated with Au NPs. In both
• cases, fast, spontaneous
• aggregation of the Au NPs was
• observed which resulted in a
• nonordered network of particles.

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Nucleic AcidNanoparticle Architectures on
Surfaces

• Nucleic acids can serve as
• templates that bind DNA-
• functionalized nanoparticles
• at complementary segments.
• When DNA templates are
• fixed at surface of a solid
• support, the resulting
• assemblies of NPs can yield
• a pattern that is dependent
• on either the shape
• produced by the DNA
• template itself or on the
• pattern produced upon its
• Immobilization.

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Biomolecule-Functionalized Nanoparticles for
Controlling DNA Reactivity

• The absorbance of a solution of the Au
• NPDNA molecular beacon conjugate 2 at
• 260 nm as a function of the time in which
• the electromagnetic field is switched on
• and off. The increase in the absorbance
• reflects the denaturation of the DNA
• Doublehelixupon local heating, whereas
• the decrease in the absorbance
• corresponds to the DNA rehybridization
• When the electromagnetic field is
• switched off. The switching between two
• distinct states is fully reversible. A
• control experiment revealed that the
• DNA molecular beacon, 3, which lacks
• the Au nanoparticle, is not affected by
• the electromagnetic field (Figure 5A,
• curve b). Although inductive heating has
• already been applied to macroscopic
• samples as well as to the treatment of

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Composite Assemblies of Nucleic Acids, Proteins,
and Nanoparticles
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• Multilayers of nanoparticles can be
• assembled on solid supports by utilizing
• DNA complementarity. For this purpose, a
• glass surface was functionalized with a
• monolayer of an oligonucleotide, 46, and
• then the surface was treated with an
• oligonucleotide, 47, which was composed of
• two domainsone domain was
• complementary to 46, whereas the second
• provided complementarity for 48. Au
• nanoparticles (13 nm) that were
• functionalized with oligonucleotide 48were
• then added to yield a monolayer of ds-DNA
• (ds-47/48) attached to the Au NPs.

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• Efficient methods for the preparation
• of semiconductor NPs (e.g. CdS, CdSe,
• PbS, ZnS) and their functionalization
• with biomolecules were recently
• developed. These NPs were applied as
• labels of biomaterials in biorecognition
• processes such as DNA sensing. For
• instance, CdS semiconductor NPs that
• were modified with nucleic acids were
• employed as tags for the detection of
• hybridization events of DNA.
• Dissolution of the CdS NPs (in the
• presence of 1m HNO3), followed by
• the electrochemical reduction of the
• Cd2 to Cd0, which accumulates
• on the electrode, and theremoval
• of the generated Cd0 (as Cd2)
• provided the electricalsignal for the
• DNA analysis.