Tu-PHS-02 - Frequency Mixing Magnetic Detection for Viscosity Sensitive Biosensing Using Magnetic Nanoparticle Relaxation

Event

EUROSENSORS 2026
2026-09-06 - 2026-09-09
Zurich

Band

Poster

Chapter

Physical Sensors

Author(s)

A. M. Pourshahidi, I. Nasr Allah, T. Bikulov, A. Abuawad, H. -J. Krause - Forschungszentrum Jülich,Jülich (Germany), A. Gholivand - University of Bonn,Bonn (Germany), U. M. Engelmann - FH Aachen University of Applied Sciences,Jülich (Germany)

Pages

568 - 569

DOI

10.5162/eurosensors2026/Tu-PHS-02

ISBN

978-3-910600-12-6

Price

free

Abstract

Frequency Mixing Magnetic Detection (FMMD) enables magnetic biosensing by probing the nonlinear dynamic response of magnetic nanoparticles (MNPs) under dual-frequency (f₁, f₂) excitation. Here, known Brownian-relaxation dominated MNPs BNF-Dextran 80 nm were studied in media with varying viscosities. The complex signal components at the mixing harmonics f₁+2·f₂ and f₁+4·f₂ were analyzed as a function of the low frequency excitation field, and the harmonic ratio R = A_(f₁+2f₂) / A_(f₁+4f₂) was evaluated as a sensitive metric. The measured ratios show a pronounced dependency on viscosity and field amplitude. The complex-plane trajectories additionally reveal viscosity-dependent changes in both amplitude and phase. These findings show that harmonic-ratio analysis in FMMD can provide environment-sensitive readout beyond conventional single-harmonic amplitude detection. The approach is therefore promising for viscosity sensitive biosensing, where target binding or matrix changes modify the local hydrodynamic environment of the MNPs.