TY  - JOUR
A1  - Pourshahidi, Ali Mohammad
A1  - Achtsnicht, Stefan
A1  - Nambipareechee, Mrinal Murali
A1  - Offenhäusser, Andreas
A1  - Krause, Hans-Joachim
T1  - Multiplex detection of magnetic beads using offset field dependent frequency mixing magnetic detection
T2  - Sensors
N2  - 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 ƒ₁ + n⋅ƒ₂, n = 1, 2, 3, 4 with ƒ₁ = 30.8 kHz and ƒ₂ = 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.
KW  - colorization
KW  - multiplex detection
KW  - frequency mixing magnetic detection
KW  - magnetic nanoparticles
Y1  - 2021
UR  - https://opus.bibliothek.fh-aachen.de/opus4/frontdoor/index/index/docId/10469
SN  - 1424-8220
N1  - This article belongs to the Special Issue "Advanced Nanomaterial-Based Sensors for Biomedical Applications"
VL  - 21
IS  - 17
PB  - MDPI
CY  - Basel
ER  -