Abstract: In one aspect, there is provided a fluorescent iron-binding compound bound to a solid phase. Also provided is a method for detecting non-transferrin bound iron in a sample, comprising contacting the sample with a fluorescent iron-binding compound bound to a solid phase and detecting a fluorescent signal derived from the fluorescent iron-binding compound bound to the solid phase, wherein the fluorescent signal is indicative of non-transferrin bound iron levels in the sample. Further provided is use of a fluorescent iron-binding compound bound to a solid phase to detect non-transferrin bound iron in a sample.