Multiplex Detection of Magnetic Beads Using Offset Field Dependent Frequency Mixing Magnetic Detection

Sensors

Ali Mohammad Pourshahidi¹  Andreas Offenhäusser¹  Hans-Joachim Krause¹  Stefan Achtsnicht¹  Mrinal Murali Nambipareechee¹ 

[1]Institute of Biological Information Processing-Biolelectronics (IBI-3), Forschungszentrum Jülich, 52425 Jülich, Germany

关键词: magnetic nanoparticles;    frequency mixing magnetic detection;    multiplex detection;    colorization;   

DOI  :  10.3390/s21175859

来源: DOAJ

【 摘 要 】

Magnetic immunoassays employing Frequency Mixing Magnetic Detection (FMMD) have recently become increasingly popular for quantitative detection of various analytes. Simultaneous analysis of a sample for two or more targets is desirable in order to reduce the sample amount, save consumables, and save time. We show that different types of magnetic beads can be distinguished according to their frequency mixing response to a two-frequency magnetic excitation at different static magnetic offset fields. We recorded the offset field dependent FMMD response of two different particle types at frequencies f₁ + n⋅f₂, n = 1, 2, 3, 4 with f₁ = 30.8 kHz and f₂ = 63 Hz. Their signals were clearly distinguishable by the locations of the extremes and zeros of their responses. Binary mixtures of the two particle types were prepared with different mixing ratios. The mixture samples were analyzed by determining the best linear combination of the two pure constituents that best resembled the measured signals of the mixtures. Using a quadratic programming algorithm, the mixing ratios could be determined with an accuracy of greater than 14%. If each particle type is functionalized with a different antibody, multiplex detection of two different analytes becomes feasible.

【 授权许可】

Unknown