Avidin Decorated Core–Shell Nanoparticles for Biorecognition Studies by Elastic Light Scattering

Abstract

In this paper, a straightforward method based on elastic light scattering is shown to provide a sensitive and reliable tool for the quantitative determination of protein-ligand interactions that occur at the surface of suitably designed core-shell nanoparticles. The assay makes use of monodisperse nanocolloids that have minimal optical contrast with the aqueous environment. By properly coating the particles with avidin and oligo(ethylene glycol)-based amphiphiles, we developed a hybrid system that combines the availability of standard ligands with the necessary bioinvisibility towards the accidental adsorption of nonspecific macromolecules. This probe was employed to detect interactions between different kinds of biotinylated proteins, and it revealed high specificity and affinities in the low nanomolar range. In particular, we obtained an efficient avidin anchorage of biotinylated protein A on the surface of the nanoparticles, which we exploited as a functional probe for the rapid, quantitative, picomolar detection of human IgG antibodies. Overall, these light-scattering-based nanosensors appear as a simple and highly informative tool for proteomics studies.

One-step bioengineering of magnetic nanoparticles via a surface diazo transfer/azide–alkyne click reaction sequence

“…Actually, it is well documented that protein immobilization onto solid surfaces may lead to partial or even complete denaturation. 19 We tested our nanoparticles observing the behavior of a MNP6 PB dispersion in the presence of anti-HSA polyclonal antibody (Sigma). The antiserum induces particle agglomeration by bridging couples of HSA molecules situated on the respective nanoparticles (Scheme 3).…”

Detection of biomolecules using light scattering

“…In this way PnP can be functionalized with the protein of interested, opportunely tagged, and thence used in protein -protein interaction studies. [7] PnPs were first partially covered by the surfactant pentaethylene glycol monododecyl ether (C12E5). C12E5 is added into the suspension in the form of solubilized micelles, which readily transfer onto the PNP surface to lower the high interfacial free energy.…”

Cellular membrane trafficking of mesoporous silica nanoparticles

“…One type of inorganic nanoparticle that has been successfully applied as a controlled-release drug delivery system is mesoporous silica nanoparticle (MSN) materials. [10][11][12][13][14][15] In the early 1990s mesoporous silica materials were discovered independently by researchers at the Mobil Oil Corporation in the US and by researchers at Waseda University in Japan. [16][17][18] The unique characteristics of MSN material make it ideal for applications in catalysis, separations, sensors, and drug delivery.…”

“…2,3 The bond formation between biotin and avidin is very rapid and once formed, is unaffected by wide extremes of pH (2-13), temperature (up to 120 °C), organic solvents and other denaturing agents. 10 Moreover, avidin can also bind compounds shown on Table 1 to form metastable complexes. 11 Thus, the biomolecule containing multilayer can be constructed by taking advantage of the stable avidin-biotin complex or other metastable avidin-biotin analogue complex.…”