ZnSe:Mn/ZnS quantum dots for the detection of microcystin by room temperature phosphorescence immunoassay

This work has assembled ZnSe:Mn/ZnS quantum dots (QDs)-monoclonal anti-microcystin-Leucine Arginine (anti-MC-LR) antibody bioconjugates as a room temperature phosphorescence (RTP) probe using 1-ethyl-3-(3-dimethyllaminopropyl) carbodiimide/N-Hydroxysuccinimide chemistry for detecting MC-LR. Once the specific interactions occurred between these MCs and their antibodies on the surface of ZnSe:Mn/ZnS QDs, the RTP of ZnSe:Mn/ZnS QDs was quenched with the increased concentration of MC-LR. Under the optimised conditions, the linear range of MC-LR was determined to be 0.9–8.8 nM. The linear relationship between ( P 0 – P )/ P 0 and concentration of MC-LR were observed with the regression equation ( P 0 – P )/ P 0 = 0.03908C + 0.0456 with the detection limit of 0.038 nM. The developed RTP immunoassay favoured environmental applications since the interference from autofluorescence and scattering light was greatly eliminated.