GMI-based biosensor for the detection and quantification of doxorubicin anticancer drugs labeled to Fe3O4 superparamagnetic nanoparticles

Abstract

We present the results of research on a Co-based giant magnetoimpedance (GMI) biosensor for Fe3O4-labelled doxorubicin (DOX) anticancer drugs. Co62Fe5Ni4Si15B14 ribbons were used as biosensing material for test solutions containing different concentrations of DOX. The plain ribbon, ribbon+Fe3O4 and ribbon+DOX2 samples exhibited low coercivity (Hc), high saturation magnetization (Ms) and low anisotropy (Hk). The GMI ratio (ΔZ/Z) increased from 33% to 38% with the increase of doxorubicin content in the ribbon. It was found that the ΔZ/Z ratio first increased rapidly up to a frequency of ∼2 MHz, and then decreased slowly as the frequency increased. While the magnetic field dependent ΔZ/Z has a single peak at 1 MHz, it has a double peak at 5 MHz. It was found that the peak height of ΔZ/Z in the ribbons with test solution of 20 ng/ml and 50 ng/ml increased by ∼3% and ∼6%, respectively, compared to the ribbon without test solution. Then the ΔZ/Z ratio decreased very rapidly with the increase of the applied external magnetic fields. The frequency-dependent GMI sensitivity (η) increased with increasing frequency and reached a maximum value at a critical frequency (∼1.6 MHz), after which it decreased. The detection sensitivity of the GMI biosensor (ξ) increased rapidly with increasing doxorubicin concentration up to ∼80 ng/ml and then remained almost unchanged. The results show that doxorubicin (DOX+Fe3O4), used as an anticancer drug, can be effectively detected even at low concentrations using the GMI based sensors fabricated in this study.