“…Interest in nanotechnology for subsurface applications, including oil and gas recovery, reservoir imaging, , CO 2 sequestration, − and environmental remediation, − has grown markedly over the past few years. In particular, superparamagnetic iron oxide nanoparticles (NPs) that have been utilized in biomedical MRI imaging , are now being explored for subsurface applications including magnetomotive acoustic imaging , and cross-well electromagnetic tomography. , These developments offer the potential to monitor reservoir fluid movement and composition between oil wells separated by hundreds of meters if NPs can be transported successfully through the reservoir. Unfortunately, the high salinities (>1 M) and often elevated temperatures (≤150 °C) found in subsurface reservoirs cause NP aggregation as well as excessive nanoparticle adsorption on mineral surfaces. ,,,, NP stabilizers may be used to attempt to overcome this drawback, but with limited success.…”