A novel method for the detection of point mutation in DNA using single-base-coded CdS nanoprobes

A novel method for DNA point mutation detection using single-base-coded CdS nanoparticle probes is proposed. Target DNA was immobilized on core/shell Fe3O4/Au magnetic nanoparticles. Single-base-coded CdS nanoparticles, such as guanosine coded CdS (G-CdS), cytidine coded CdS (C-CdS), thymidine coded CdS (T-CdS) and adenosine coded CdS (A-CdS) were used as the probes to identify the mutation sites in DNA strand. The hybridization process of single-base-coded CdS nanoparticle probes with the mutation sites in DNA was monitored using piezoelectric quartz crystal microbalance (QCM). The hybridization of the mutation base in DNA with its complementary base-coded CdS nanoprobes specifically caused significant changes in the resonance frequency of the QCM. Thus the base types of the mutation sites in DNA strand could be identified. The results were further confirmed by fluorescence measurement of CdS. Owing to its operation convenience and cost-effective, this DNA point mutation detection method is expected to hold a great promise in the detection of DNA point mutation and genetic assays. (C) 2008 Elsevier B.V. All rights reserved.