Quantum-dot Submicrobead-Based Immunochromatographic Strip for Rapid and Quantitative Detection of Plasmodium Falciparum

A Cd Te / Zn Se quantum-dot submicrobead( QBs), which exhibited fluorescence intensity approximately 2800-fold stronger than that of single quantum dots,was conjugated with the anti-histidine rich protein( HRP)-Ⅱ m Abs using N-( 3-( Dimethylamino) propyl)-N'-ethylcarbodiimide hydrochloride( EDC)method as fluorescence probe. The goat anti-HRP-Ⅱ polyclonal antibodies and donkey anti-mouse polyclonal antibodies were sprayed onto the nitrocellulose membrane as test line and control line,respectively. The resultant fluorescence probes were introduced to the immunochromatographic strip for the quantitative determination of Plasmodium falciparum. For determination of Plasmodium falciparum in serum,the QBs based immunochromatographic strips exhibited a good dynamic linear range from 5. 8 Parasite / μL to8010 Parasite / μL with a limit of detection of 5. 8 Parasite / μL. The detection time of the proposed QBs based immunochromatographic strips for each sample was only 15 min. Moreover,the recovery rates of the intra- and inter-assay ranged from 93. 0% to 111. 9%,and 98. 3% to 115. 1% respectively,while the relative standard deviations( RSDs) of intra- and inter-assay were below 5%.