Blue emitting persistent phosphor compositions as diagnostic reporters

A method for detection of at least one analyte of interest in a sample, wherein the method comprises:

• associating the sample with a surface comprising a first analyte binding agent, wherein the associating results in the immobilization of at least some of the analytes present in the sample on the surface;
• contacting the analyte present in the sample with a composition comprising at least one phosphor compound,
• wherein the at least one phosphor compound is linked to a second analyte binding agent,
• wherein the at least one phosphor compound is (Sr1-δBaδ)2MgSi2O7:Eu2+Dy3+,
• wherein δ is between 0 and 0.375, and
• wherein the at least one phosphor compound is in the form of particles
• wherein the associating and contacting result in the formation of immobilized first analyte binding agent-analyte-second analyte binding agent-phosphor complexes on the surface;
• detecting a presence or absence of a luminescence signal from the immobilized complexes wherein the detecting comprises:
• exciting the phosphor compound with a light source;
• detecting the emitted luminescence signal from the excited phosphor compound;
• and
• correlating the luminescence signal to the presence or absence of the analyte in the sample.