Molecular Sensors with Modified Ligands

The present disclosure generally relates in certain embodiments to a magnetic imaging kit for biochemical sensing, e.g., for detection of analytes, via magnetic imaging techniques. For instance, in one set of embodiments, the kit comprises a collection of magnetic imaging agents (e.g. superparamagnetic iron oxide nanoparticles) and linker species (e.g. a catechol, phosphothreonine, and/or derivative thereof) with a molecular weight of less than or equal to 1000 Da, or less than or equal to 500 Da. The magnetic imaging agents may sense the presence of an analyte via aggregation or disaggregation of the two or more magnetic imaging agents. In addition, certain aspects are directed to a method of exposing two or more magnetic imaging agents to a region on or in a subject and imaging the region to determine the analyte.