Biomolecule-nanoparticle hybrid
Biomolecules, such as proteins (enzymes, antigens, antibodies) or DNA and nanomaterials, such as metal or semiconductor nanoparticles and nanorods have dimensions similar to each other. Hence integration of nanoparticles, with unique electronic, photonic, and catalytic properties, with biomaterials, which display unique recognition, catalytic, and inhibition properties, yields novel hybrid nanobiomaterials of synergetic properties and function. Nanobiomaterials are emerging as the most promising area of research within the area of biological materials science and engineering
Au-NP nanobiomaterials
Biomolecule-nanoparticle hybrid systems are used for bioelectronic applications by the electrical contacting of redox enzymes by means of Au-NPs. The enzymes, glucose oxidase, GOx, and glucose dehydrogenase and GDH are electrically contacted with the electrodes by the reconstitution of the corresponding apo-proteins on flavin adenine dinucleotide (FAD) or pyrroloquinoline quinone (PQQ)-functionalized Au-NPs (1.4 nm) associated with electrodes, respectively.
Similarly, Au-NPs integrated into polyaniline in a micro-rod configuration associated with electrodes provide a high surface area matrix with superior charge transport properties for the effective electrical contacting of GOx with the electrode.
Synthesis of nano gold biomaterials
Synthesis of gold nanoparticle (Au NP) containing both antisense oligonucleotides and synthetic peptides synthesis is accomplished by mixing thiolated oligonucleotides and cysteine-terminated peptides with gold nanoparticles in the presence of salt, which screens interactions between biomolecules, yielding a densely functionalized nanomaterial. Surface loading of each biomolecule can be controlled by controlling the stoichiometry of the components in solution.
Preparation of Au NP–biomolecule conjugates have primarily focused on two classes of materials: homofunctionalized nanoparticles that incorporate one biomolecule functionality, such as DNA, peptides, or antibodies, and heterofunctionalized nanoparticles including conjugates that combine oligonucleotides and antibodies, protein-stabilized DNA-peptide conjugates, alkyl chains and plasmid DNA, or polyethylene glycol and peptides.
Applications
Biomolecule-semiconductor NP hybrid systems are used for the development of photo electrochemical sensors and optoelectronic systems.
Biomolecule-Au-NP hybrids
Biomolecule-Au-NP hybrids use of Au-NPs as carriers for a nucleic acid composed of hemin/G-quadruplex DNAzyme units and a detecting segment complementary to the analyte DNA. The functionalized Au-NPs are employed for the amplified DNA detection, and for the analysis of telomerase activity in cancer cells, using chemiluminescence as a readout signal.
Acetylcholine esterase (AChE)/CdS-NPs immobilized in a monolayer configuration on an electrode can generate photocurrent in the presence of thioacetylcholine as substrate and provides a means to probe the AChE activity.
The association CdS-NP/double-stranded DNA hybrid systems with an Au-electrode, and the intercalation of methylene blue into the double-stranded DNA, generate an organized nanostructure of switchable photo electrochemical functions.
The oxidation of the intercalator yields in the presence of triethanolamine, TEOA, as sacrificial electron donor, an anodic photocurrent by the transport of conduction-band electrons, through intercalator units, to the electrodes, and filling the valance-band holes with electrons supplied by TEOA giving a potential-switchable directions of the photocurrents, and reveal logic gate functions.
Self-cleaning nanobiomaterials
Researchers at Rensselaer Polytechnic Institute in Troy, NY used nanotechnology to design a self-cleaning plastic in which the enzyme molecules are an integral part of the material. When the plastic comes into contact with bacteria or other pathogens, the enzymes attack the microbes and destroy their ability to bind to its surface. Researchers attached enzymes to the surface of large carbon nanotubes which stabilize the enzymes, are then incorporated into a polymer. The technique could work for any number of enzymes including materials that kill specific microbes or even degrade oil sludge on contact. Coatings of the enzyme-polymer material could protect implantable medical devices from scar tissue formation. The unique properties of nanobiomaterials provide advantageous interactions with the proteins that control cellular function. Nanobiomaterials have an increased number of atoms and crystal grains at their surfaces and possess a higher surface area to volume ratio than conventional micro scale biomaterials. These differences in surface topography alter the corresponding surface energy for protein adsorption.
Nanobiomaterials for biosensors
Bionanomaterial research has emerged as a new exciting field, recognized as a new interdisciplinary frontier in the field of life science and material science. Great advances in nanobiochip materials, nanoscale biomimetic materials, nanomotors, nanocomposite materials, interface biomaterials, nanobiosensors, and nano-drug-delivery systems have the enormous prospect in industrial, defense, and clinical medicine applications. Biomolecules assume the very important role in nanoscience and nanotechnology, for example, peptide nucleic acids (PNAs) replace DNA, act as a biomolecular tool/probe in the molecular genetics, diagnostics, cytogenetics, and have enormous potentials in pharmaceutics for the development of biosensors.
Nanobiomaterials as catalyst
Biological macromolecules such as proteins and DNA are versatile supports for organizing nanostructures and catalysts. Catalysts, including biocatalysts, capable of carrying out the multi-electron chemistry needed to produce solar fuels require multiple chemically distinct catalytic centers. These catalytic centers often involve metal ions in paramagnetic states to maximize reactivity and product distribution.
Nanobiomaterials in health care
Biomaterials are used to develop advanced medical devices to improve the course of human life. Nanobiomaterials can be used for human implant, orthopedics, drug delivery, gene therapy, antimicrobial treatments, array technologies, and diagnostics. Nanobiomaterials help with targeting, measuring, sensing, and imaging. They can also help enhance efficiency, safety, quality, and durability.