| 1. |
- Eberbeck, Dietmar, et al.
(författare)
-
AC susceptometry and magnetorelaxometry for magnetic nanoparticle based biomolecule detection
- 2009
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Functionalized magnetic nanoparticles are increasingly used as probes in biomolecule detection. We compared two different techniques, which provide information on the state of the magnetic particle system. The dynamics of an ensemble of magnetic nanoparticles was probed measuring the response its magnetisation both on an alternating magnetic field by AC-susceptometry and on a jump of external magnetic field by magnetorelaxometry. In order to compare both techniques, we studied the binding of streptavidin functionalized nanoparticles (fluidMAG/BC-SAV) to biotin-agarose beads and to biotinylated prostate specific antigens (PSA-10). By both techniques we observed specific changes in shape and amplitude of the characteristic signals due the binding of the particles. Therewith the signals of bound and unbound probes can be discriminated and a homogeneous assay without time-comsuming washing steps is realized. The AC susceptometry method provides a robust and sensitive measurement technology. Magnetorelaxometry, utilizing superconducting quantum interference devices (SQUIDs) as magnetic field sensors, owns a much shorter measurement time and has the potential of an even higher sensitivity, at the expense of a considerably increased technological effort.
|
|
| 2. |
- Schaller, Vincent, 1979, et al.
(författare)
-
Development of an electrowetting-based microfluidic platform for magnetic immunoassays
- 2009
-
Ingår i: 13th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2009; Jeju; South Korea; 1 November 2009 through 5 November 2009. - 9780979806421 ; , s. 85-87
-
Konferensbidrag (refereegranskat)abstract
- We report the transport of magnetic nanoparticles (MNPs) in suspension in a 2 μl de-ionized water droplet (DIWD) using ElectroWetting-On-Dielectic (EWOD) actuation, and the detection of the MNPs by magnetic AC-susceptibility measurements using a highly sensitive high-Tc dc Superconducting Quantum Interference Device (SQUID) gradiometer. These results constitute the first development step towards a MNP-based magnetic immunoassay platform with SQUID-readout and sample droplet handling.
|
|
| 3. |
|
|
| 4. |
- Schaller, Vincent, 1979, et al.
(författare)
-
Towards an electrowetting-based digital microfluidic platform for magnetic immunoassays
- 2009
-
Ingår i: Lab on a Chip - Miniaturisation for Chemistry and Biology. - : Royal Society of Chemistry (RSC). - 1473-0189 .- 1473-0197. ; 9:23, s. 3433-3436
-
Tidskriftsartikel (refereegranskat)abstract
- We demonstrate ElectroWetting-On-Dielectric (EWOD) transport and SQUID gradiometer detection of magnetic nanoparticles (MNPs) suspended in a 2 mu l de-ionized water droplet. This proof-of-concept methodology constitutes the first development step towards a highly sensitive magnetic immunoassay platform with SQUID readout and droplet-based sample handling. Magnetic AC-susceptibility measurements were performed on MNPs with a hydrodynamic diameter of 100 nm using a high-Tc dc Superconducting Quantum Interference Device (SQUID) gradiometer as detector. We observed that the signal amplitude per unit volume is 2.5 times higher for a 2 ml sample droplet compared to a 30 ml sample volume.
|
|
| 5. |
|
|
