A responsive particulate MRI contrast agent for copper(i): a cautionary tale
Year: 2012
Type: article
Abstract: A responsive MION-based MRI contrast agent for the detection of copper(I) is presented. Induced agglomeration of azide and acetylene-functionalized magnetite nanoparticles via Cu(I)-catalysed Huisgen cycloaddition leads to significant decrease in longitudinal relaxivity due to the slow exchange of water molecules trapped within the cluster with bulk solvent. Agglomeration leads to an initial two-fold increase followed by a sharp and almost complete loss in transverse relaxivity for clusters larger than 200 nm in size. The decrease in r(2) for clusters reaching the static dephasing regime has two significant implications for particulate responsive MRI contrast agents. First, the maximum increase in r(2) is barely two-fold, second, since r(2) does not increase continuously with increasing cluster size, the r(1)/r(2) ratio cannot be used to determine the concentration of an analyte ratiometrically.
Source: Dalton Transactions
DOI: 10.1039/c2dt30416c
Institution: University of Minnesota
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, National Institutes of Health, College of Science and Engineering, University of Minnesota, Materials Research Science and Engineering Center, Harvard University, National Institute of General Medical Sciences, National Institute of Biomedical Imaging and Bioengineering, Division of Materials Research, National Center for Research Resources
OpenAlex ID: W2062542425