Nano Particles

When nanoparticles are used as quantitation tags, either the particles themselves or a measurable parameter emanating from the particles (e.g. photons) are quantified. Encoded nanoparticles used as substrates rely on one or more identifiable characteristics to allow them to serve as encoded physical hosts for multiplexed bioassays. This is analogous to the positional encoding of assays on microarrays, but in solution. Nanoparticles that leverage signal transduction involve a change either in the location of nanoparticles relative to one another, or a perturbation in the biological system caused by the nanoparticle — both of which, in turn, lead to a change in a measurable signal. Functional nanoparticles exploit specific physical or chemical properties of nanoparticles to carry out novel functions, such as catalysis of a biological reaction. For certain particles and/or applications, these divisions can be blurred, but they nonetheless serve as a general classification method.


Penn et al, Nanoparticles for bioanalysis, sciencedirect.com, Volume 7, Issue 5, October 2003, Pages 609-615



To obtain lectins without tedious purification steps, a convenient method for a one-step purification of lectins using sugar-immobilized gold nano-particles (SGNPs)was developed. Proteins in crude extracts from plant materials were precipitated with 60% ammonium sulphate, and the precipitate was re-dissolved in a small volume of phosphate buffer. The resultant solution was then mixed with appropriate SGNPs under an optimized condition. After incubating overnight at 4°C, lectins in the mixture formed aggregate with SGNPs, which was visually detected and easily sedimented by centrifugation. The aggregate was dissolved by adding inhibitory sugars, which were identical to the non-reducing sugar moieties on the SGNPs. According to SDS–PAGE and MS of thus obtained proteins, it was found that SGNPs isolated lectins with a high purity. For example, a protein isolated from banana using Glc{alpha}-GNP ({alpha}-glucose-immobilized gold nano-particle) was identified as banana lectin by trypsin-digested peptide-MS finger printing method.


One-Step Purification of Lectins from Banana Pulp Using Sugar-Immobilized Gold Nano-Particles; the journal of Biochemistry; bj.oxfordjournals.org


Particles:

In chemistry:

• Colloidal particle, part of a one-phase system of two or more components

In physics:
• Subatomic particle, which may be either:
o Elementary particle, a particle of which larger particles are composed, also called a fundamental particle
o Composite particle, a bound state between several elementary particles
o Point particle, an idealized particle that does not have any volume
• See also list of particles


In other contexts:
• Particle (ecology), in marine and freshwater ecology, a small object
• Particulate matter, in the areas of atmospheric physics and air pollution
• Particle (nanotechnology), a small object that behaves as a whole unit in terms of its transport and properties
• Grammatical particle, in linguistics, a useful catch-all lacking a strict definition
• Particle system, in computer graphics, a technique to simulate certain fuzzy phenomena
• Particle (band), a 2000 jam band from Los Angeles, California


Source: wikipedia