a biomaterial diagnostic apparatus comprising an injection unit into which a biomaterial is injected and a reaction unit which includes a conjugate comprising a fluorophore and a molecule that binds the biomaterial, the fluorophore having a linear upconversion fluorescent property, wherein the conjuate forms a reaction complex with the biomaterial;

a light source unit configured to provide a light source to the reaction unit of the biomaterial diagnostic apparatus;

an emission signal collection unit configured to collect an emission signal with a wavelength range 10 to 100 nm shorter than that of excitation light exciting the fluorophore of the reaction complex; and

a measurement unit configured to detect and measure the collected emission signal,

wherein the light source unit provides a light source with a wavelength 5 to 50 nm longer than the maximum emission wavelength of the fluorophore, wherein the fluorophore has a Stokes' shift of <100 nm, and

wherein the fluorophore comprises a diketo pyrrolo pyrrole (DPP) derivative, wherein said DPP derivative is selected from the group consisting of 2,5-bis(2-ethylhexyl)-3,6-di(thiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione; 2,5-bis(2-ethylhexyl)-2,5-dihydro-3,6-diphenyl-pyrrolo[3,4-c]pyrrole-1,4-dione; 5-(2,5-bis(2-ethylhexyl)-1,2,4,5-tetrahydro-1,4-dioxo-3-(thiophen-2-yl)pyrrolo[3,4-c]pyrrol-6-yl)thiophene-2-carbaldehyde; and 5,5′-(2,5-bis(2-ethylhexyl)-3,6-dioxo-2,3,5,6-tetrahydropyrrolo[3,4-c]pyrrole-1,4-diyl)bis(thiophene-2-carbaldehyde).