Detection of DNA via the Fluorescence Quenching of Mn-doped ZnSe D-dots/Doxorubicin/DNA Ternary Complexes System

This manuscript reports a method for the detection of double-stranded DNA, based on Mn:ZnSe d-dots and intercalating agent doxorubicin (DOX). DOX can quench the photoluminescence (PL) of Mn: ZnSe d-dots through photoinduced electron transfer process, after binding with Mn: ZnSe d-dots. The addition of DNA can result in the formation of the Mn: ZnSe d-dots-DOX-DNA ternary complexes, the fluorescence of the Mn: ZnSe d-dots-DOX complexes would be further quenched by the addition of DNA, thus allowing the detection of DNA. The formation mechanism of the Mn: ZnSe d-dots-DOX-DNA ternary complexes was studied in detail in this paper. Under optimal conditions, the quenched fluorescence intensity of Mn: ZnSe d-dots-DOX system are perfectly described by Stern-Volmer equation with the concentration of hsDNA ranging from 0.006 mu g mL(-1) to 6.4 mu g mL(-1). The detection limit (S/N=3) for hsDNA is 0.5 ng mL(-1). The proposed method was successfully applied to the detection of DNA in synthetic samples and the results were satisfactory.