Gold Nanoparticles are most extensively nanomaterials for biomedical application due to their unique
properties, such as rapid and simple synthesis, large surface area, strong adsorption ability and facile
conjugation to various biomolecules. The remarkable photo-physical properties of Gold Nanoparticles For
Biosensor have provided plenty of opportunities for the preparation of Gold Nanoparticles For Biosensor-based
optical biosensors, while the excellent biocompatibility, conductivity, catalytic properties have facilitated the
application of gold Nanoparticles in the contraction of electrochemical biosensors
Gold Nanoparticles For Biosensor Gold Nanoparticles For Biosensor technology plays a key role in targeted
sensing of selective bio-molecules using functionalized gold nanoparticles (Au NPs). Au NP-based sensors are
expected to change the very foundations of sensing and detecting bio-molecules. The use of surface
functionalized Au NPs for smart sensor fabrication leading to detection of specific bio-molecules In addition to
sensing, gold nanoparticles are attractive candidate for photo-thermal therapeutic, diagnostic, and drug delivery
applications. Bioimaging and therapeutic applications of these unique nanomaterials will be described of their
tuneable optical properties, which strongly depend on the particle size, shape, composition, and surface coating
Sensing of DNA and Oligonucleotides: The sensitivity and selectivity response to the biological environment,
the optical properties of Gold Nanoparticles For Biosensor have been used in sensing biological molecules and
cells. Various Au NP formulations have been fabricated for targeting biological targets, such as DNA, RNA, cells,
metal ions, small organic compounds, protein, and many more of biological specimens. Detection of DNA,
aptamers, and oligonucleotide has received great attention in the past few years because it has important
applications in medical research and diagnosis and food and drug industry monitoring. Majority of the assays
identify specific sequence through hybridization of an immobilized probe to the target analyte after the latter
has been modified with a covalently linked optical probe. Currently, many research teams have developed DNA,
aptamers, and oligonucleotide detection schemes that involve the use of chemically functionalized Au NPs .
These approaches are simple and straightforward and use facile NPs surface functionalization chemistry and
usually do not require expensive instrumentation.
Cell Detection and Labeling with Functionalized Au NPs:
Molecular imaging methods are often used to image and detect tumor cells. Among them, fluorescence
microscopy is preferable technique for tissue and cells investigation with high resolution. However, this
technique suffers from low sensitivity and tedious steps are needed to prepare the samples for imaging. For this
reason, area efforts have been made to develop efficient biosensors aimed at improving the detection signals
for accurate diagnosis of diseases. The design and construction of a successful biosensor with high detection
limit is a primary goal toward the development of high detection limit for sensing cancer cells. The preparation
of nano composite gel by neutralizing a designer nano composites solution of chitosan-encapsulated Au NPs.
The gel was designed for immobilization and electro chemical study of cells and monitoring adhesion,
proliferation of cells on electrodes. The ICG Au NPs provides spatially localized chemical information from the
cell environment by monitoring the SERS local optical fields of the Au NPs. The functionalized Au NPs offer the
potential to enhance the spectral specificity and selectivity of current chemical analysis approaches of living cells
based on vibrational information. Physical and biological features of the Au NPs networks offer multimodalities
for nanobiomedical imaging applications.
Proteins have complementary counter parts that are similar to oligonucleotide strands. Protein targets
biomolecules can be anchored to Gold Nanoparticles For Biosensor surface for their specific detection together
with other sensing agents and tools. Au NPs can be applied to detect multiple protein targets through a single
screening test. Demonstrated that the unique optical properties of Au NPs can be used to develop a label-free
biosensor in a chip format. Sensor chips were fabricated by chemisorptions of Au NPs on amine-functionalized glass.
SENSING OF GLUCOSE:
The development of fast and reliable sensing devices in monitoring of glucose for the treatment and control of
diabetes has always been an important research topic for the last decade. Electrochemical methods are
considered to be useful for sensing glucose because higher sensitivity detection can be achieved. Most of the
electrochemical methods are based on the use of the enzyme glucose oxidase that selectively catalyzes the
oxidation of glucose to glucolactone. The fabrication of glucose biosensor by covalent attachment of glucose
oxidase to Gold Nanoparticles For Biosensor-modified Au electrode. Cyclic voltammetry and electrochemical
impedance spectroscopy were used to confirm the assembly process of biosensor and suggested that the Au
NPs in the biosensing interface effectively enhanced the electron transfer between analyte and electrode
surface. Cyclic voltammetry performed in the presence of glucose and artificial redox mediator,
ferrocenemethanol, allowed the quantification of the surface concentration of electrically wired enzyme. The Au
NPs efficiently catalyzed the oxidation of glucose in phosphate buffer solution in the absence of any enzymes or
redox mediators. Au NPs can be integrated into sensing devices for real-time monitoring of blood sugar that will
enable clinicians to develop personalized medicine for the individual patients.
BIOSENSORS FOR DETECTION OF ENZYME ACTIVITY:
Despite of the many interesting physicochemical properties of Gold Nanoparticles For Biosensor, the majority of
Au NP’s-based enzyme assays exploit one of the following two Au NP’s characteristics: (i) the surface plasmon
absorption of Au NP’s; and (ii) their ability to quench fluorescence. Because of these properties, Au NP’s have
been used in colorimetric-based and Fo¨rster resonance energy transfer (FRET)-based enzyme assays. In
addition to colorimetric and FRET-based assays, other detection systems have been described for Au NP’s-based
enzyme activity determination, most notably electrochemical and light-scattering measurements.Optimal
enzyme activity is essential for maintenance of physiological homeostasis. Many pharmacological agents are activators and inhibitors of enzymes. It is essential, therefore, in the development of drugs as enzyme activators and inhibitors, that enzyme activities be accurately measured under physiological and pathological conditions.
Different biochemical assays have been developed for this purpose, some of which are based on nano
structured materials. Gold Nanoparticles For Biosensor can be attached to many traditional biological probes
such as antibodies, lectins, super antigens, glycans, nucleic acids, and receptors. Au NP’s are used as catalysts
and as imaging and therapeutic agents., Au NP’s have been proposed as signal transducers for biosensors.
Au NP’s are used in cancer treatment using optical transparencies. Au NP’s are delivered to cancer cell using
effective drug delivery then cancer tissue are exposed to UV light and Au NP’s absored the energy and thermal
vibration break the cancer tissue in small cell and using chemotherapy these small celll are destroyed. Thus use
less amount of drug so less side effect.