Development of fluorescence immunoassay based on cadmium sulphide (cds) quantum dots for the detection of endosulfan

Deepak T. S., Rashmi S.Shenoy and H.K.Manonmani

Introduction: Cadmium sulfide quantum dots were used for a sensitive detection of endosulfan. Cadmium sulfide (CdS) quantum dots (QDs) (nanoparticles) were synthesized, purified and attached to anti-endosulfan IgY antibodies for the detection of endosulfan. Followed by the concentration of antibody optimization, the fluorescence-linked immunoassay method was based.

Results: The method used the QDs as the signal to quantify endosulfan. Compared with the chromogen based enzyme-linked immunosorbent assay (ELISA), QD-based ELISA saved time and decreased the false-positive results because of specified emission wavelength of QDs. The 50% inhibitory concentration (IC50) of the QD-ELISA method was 0.28 mg mL-1 with a detection limit of 25 ng mL-1,and the linear range was 60ngmL-1-3.83mgmL-1. Endosulfan residues in spiked samples were also determined. The recovery of endosulfan in water samples ranged from 84.5% to 96.2% and that in vegetables ranged from 72.5% to 125.7 %.

Conclusion: Among food matrices used, Lemon Rice interfered in the quantitative detection of endosulfan. However, the detection of the endosulfan residues in the environment and food samples is rapid, sensitive and accurate.

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