Chitosan encapsulated quantum dots platform for leukemia detection

We report results of the studies relating to electrophoretic deposition of nanostructured composite of chitosan (CS)–cadmium-telluride quantum dots (CdTe-QDs) onto indium-tin-oxide coated glass substrate. The high resolution transmission electron microscopic studies of the nanocomposite reveal molecular level coating of the CdTe-QDs with CS molecules in the colloidal dispersion medium. This novel composite platform has been explored to fabricate an electrochemical DNA biosensor for detection of chronic myelogenous leukemia (CML) by immobilizing amine terminated oligonucleotide probe sequence containing 22 base pairs, identified from BCR–ABL fusion gene. The results of differential pulse voltammetry reveal that this nucleic acid sensor can detect as low as 2.56 pM concentration of complementary target DNA with a response time of 60 s. Further, the response characteristics show that this fabricated bioelectrode has a shelf life of about 6 weeks and can be used for about 5–6 times. The results of experiments conducted using clinical patient samples reveal that this sensor can be used to distinguish CML positive and the negative control samples.

► In the present manuscript, electrophoretic deposition of chitosan encapsulated CdTe quantum dots onto indium-tin-oxide coated glass substrates has been reported for the first time.
► This nanocomposite has been utilized for the fabrication of bioelectrodes for the detection of leukemia by immobilizing the specific probe DNA sequence identified from BCR–ABL gene.