A new approach for bioassays based on frequency- and time-domain measurements of magnetic nanoparticles
| Autor: | Dag Winkler, Alexey Kalabukhov, Christer Johansson, Fredrik Öisjöen, Justin F. Schneiderman, Andrea Prieto Astalan |
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| Rok vydání: | 2009 |
| Předmět: |
Analyte
Biomedical Engineering Biophysics Nanotechnology Biosensing Techniques Sensitivity and Specificity law.invention Magnetics law Electrochemistry Bioassay Time domain Sensitivity (control systems) chemistry.chemical_classification Immunomagnetic Separation Biomolecule Bioassay Measurement Reproducibility of Results General Medicine Equipment Design SQUID Equipment Failure Analysis chemistry Magnetic nanoparticles Nanoparticles Biological Assay Biological system Biotechnology |
| Zdroj: | Biosensorsbioelectronics. 25(5) |
| ISSN: | 1873-4235 |
| Popis: | We demonstrate a one-step wash-free bioassay measurement system capable of tracking biochemical binding events. Our approach combines the high resolution of frequency- and high speed of time-domain measurements in a single device in combination with a fast one-step bioassay. The one-step nature of our magnetic nanoparticle (MNP) based assay reduces the time between sample extraction and quantitative results while mitigating the risks of contamination related to washing steps. Our method also enables tracking of binding events, providing the possibility of, for example, investigation of how chemical/biological environments affect the rate of a binding process or study of the action of certain drugs. We detect specific biological binding events occurring on the surfaces of fluid-suspended MNPs that modify their magnetic relaxation behavior. Herein, we extrapolate a modest sensitivity to analyte of 100 ng/ml with the present setup using our rapid one-step bioassay. More importantly, we determine the size-distributions of the MNP systems with theoretical fits to our data obtained from the two complementary measurement modalities and demonstrate quantitative agreement between them. |
| Databáze: | OpenAIRE |
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