000202413 001__ 202413
000202413 005__ 20181203023632.0
000202413 0247_ $$2doi$$a10.1021/ac501568g
000202413 022__ $$a0003-2700
000202413 02470 $$2ISI$$a000340701500028
000202413 037__ $$aARTICLE
000202413 245__ $$aMagnetic Particle-Scanning for Ultrasensitive Immunodetection On-Chip
000202413 260__ $$aWashington$$bAmerican Chemical Society$$c2014
000202413 269__ $$a2014
000202413 300__ $$a11
000202413 336__ $$aJournal Articles
000202413 520__ $$aWe describe the concept of magnetic particle-scanning for on-chip detection of biomolecules: a magnetic particle, carrying a low number of antigens (Ag's) (down to a single molecule), is transported by hydrodynamic forces and is subjected to successive stochastic reorientations in an engineered magnetic energy landscape. The latter consists of a pattern of substrate-bound small magnetic particles that are functionalized with antibodies (Ab's). Subsequationuent counting of the captured Ag-carrying particles provides the detection signal. The magnetic particle-scanning principle is investigated in a custom-built magneto-microfluidic chip and theoretically described by a random walk-based model, in which the trajectory of the contact point between an Ag-carrying particle and the small magnetic particle pattern is described by stochastic moves over the surface of the mobile particle, until this point coincides with the position of an Ag, resulting in the binding of the particle. This model explains the particular behavior of previously reported experimental dose-response curves obtained for two different ligand-receptor systems (biotin/streptavidin and TNF-alpha) over a wide range of concentrations. Our model shows that magnetic particle-scanning results in a very high probability of irrununocomplex formation for very low Ag concentrations, leading to an extremely low limit of detection, down to the single molecule-per-particle level. When compared to other types of magnetic particle-based surface coverage assays, our strategy was found to offer a wider dynamic range (>8 orders of magnitude), as the system does not saturate for concentrations as high as 10(11) Ag molecules in a 5 mu L drop. Furthermore, by emphasizing the importance of maximizing the encounter probability between the Ag and the Ab to improve sensitivity, our model also contributes to explaining the behavior of other particle-based heterogeneous immunoassays.
000202413 700__ $$0245430$$aCornaglia, Matteo$$g196273
000202413 700__ $$0247329$$aTrouillon, Raphael$$g236702
000202413 700__ $$aTekin, H. Cumhur
000202413 700__ $$0240962$$aLehnert, Thomas$$g113381
000202413 700__ $$0242801$$aGijs, Martin A. M.$$g113762
000202413 773__ $$j86$$k16$$q8213-8223$$tAnalytical Chemistry
000202413 8564_ $$s1819661$$uhttps://infoscience.epfl.ch/record/202413/files/M.%20Cornaglia%20et%20al.%20-%20AnalChem%202014.pdf$$yn/a$$zn/a
000202413 909C0 $$0252094$$pLMIS2$$xU10322
000202413 909CO $$ooai:infoscience.tind.io:202413$$pSTI$$particle
000202413 917Z8 $$x113762
000202413 917Z8 $$x113381
000202413 937__ $$aEPFL-ARTICLE-202413
000202413 973__ $$aEPFL$$rREVIEWED$$sPUBLISHED
000202413 980__ $$aARTICLE