Fluorescent switch based on QDs modified DNA probe and NiTPP for simultaneous dual color sensitive sensing of HPV16 and HPV18

Persistent infection with human papillomavirus (HPV) is a major cause of cervical cancer and other cancers. Rapid and accurate detection of high-risk HPV16 and HPV18 is of great importance in clinical research. In this paper, a novel "off-on" sensor based on a water-soluble dual-color fluorescent CdTe QDs-ssDNA probe was constructed. The hydrothermal approach was used to create the green and red emitting CdTe QDs as fluorescence signals. Porphyrin derivatives (NiTPP) were then used to quench the fluorescence of CdTe QDs, and the synthesis conditions of NiTPP were modified to maximize the effectiveness of quenching QDs due to the Fo center dot rster resonance energy transfer (FRET) and photo-induced electron transfer (PET) effects. As QDs-ssDNA were being released from the NiTPP surface due to the particular recognition effect of DNA molecular hybridization, various levels of fluorescence were also restored. This allowed for the quantitative detection of HPV16 and HPV18. In vitro detection of HPV16 and HPV18 had good linearity in the range of 0.1-40 nM and 0.05-40 nM, and the limits of detection were 62 pM and 40 pM, respectively, which provided a way for simultaneous detection of multiple subtypes of DNA.