Magnetic force microscopy (MFM) is a widely-used technique for measuring the local magneticrnproperties of a variety of materials. This method covers a large field of applicationsrnranging from fundamental research of micro-magnetic phenomena to industrial applicationsrnin the development of magnetic recording components.rnThe image formation in MFM measurements is based on the magneto-static interactionrnof a sharp magnetic tip with the probed sample. Despite the fact that MFM is quiterneasy to perform, image interpretation remains challenging. This is due to the accuraterncharacterization of the probing tip that is needed for a quantitative interpretation of thernMFM data in terms of the local magnetic properties of the sample.rnThis thesis examines the fabrication and utilization of special MFM probes based onrnsingle ferromagnetic nanoparticles as the magnetically interacting element. A magneticrnprobe that consists of a very small magnetic single-domain particle can be accuratelyrndescribed by a magnetic point dipole. Such a probe potentially yields an improved lateralrnresolution and a simplified quantitative interpretation of MFM images compared to arnstandard thin-film coated MFM tip.rnFirst of all, one part of this thesis examines the fabrication of suitable single-domainrnparticles. In particular, this part is focussed on experiments concerning the protectionrnof these particles from oxidation in ambient conditions. To this end, these ferromagneticrnparticles were coated with gold using the light-induced deposition of gold in a photoactivernmetal-salt solution. The chemical surface passivation of the particles by the gold coatingrnwas verified using different techniques (SQUID, MFM).rnIn the next step, these particles were mechanically affixed to a standard silicon tip ofrnatomic force microscopy (AFM). The controlled attachment of a single particle, as well asrnthe attachment of multiple particles to such a Si-AFM tip was demonstrated.rnAnother part of the thesis examines the magnetic imaging with particle based probes inrnMFM experiments. A minimum of four cobalt particles affixed to the tip was determinedrnas the threshold for obtaining a reasonable MFM signal. It was possible to image thernmagnetic domain structure of a hard disk drive sample with these particle probes. Usingrna simulation of the MFM data, the orientation and the position of the effective tip dipolernwere determined. The effective dipole moment of the tip is found by a calibration experimentrnassuming a magnetic dipole-dipole interaction between the tip and another magneticrnparticle.