Fluorescence turn-on immunoassay of endocrine diethyl phthalate in daily supplies using red fluorescent carbon dots

Diethyl phthalate (DEP), as the environmental endocrine, would interfere with people’s endocrine system and has greatly harm in health. Here a sensitivity, eco-friendly fluorescence immunoassay technique was established based on “turn-on” red carbon dots (R-CDs) conjugated anti-DEP antibody (Ab) as the immunoprobe for the detection of DEP in daily supplies. The R-CDs will “turn-on” fluorescence when it in formamide solution, due to the change of the electron distribution on the surface and electronic charge transfer of the red carbon dots. The use of “turn-on” R-CDs as immunoprobe effectively increased the sensitivity of the immunoassay. Moreover, the R-CDs conjugated anti-DEP Ab without any additional embellishment. Under the optimal conditions, a good linear was established with the DEP concentration range of 5 × 10 −2 ng/mL–10 ng/mL, the low limit of detection (LOD) of the proposed method was 0.0056 ng/mL. This project has satisfactory accuracy with recoveries ranging from 96.0% to 115.1%. Our research provides an accurately, simply and sensitivity strategy to detect the content of environmental endocrine DEP in daily supplies.