Miao Yanming, Li Yuting, Zhang Zhifeng, Yan Guiqin, Bi Yi
Shanxi Normal University, Linfen 041004, People's Republic of China.
Shanxi Normal University, Linfen 041004, People's Republic of China.
Anal Biochem. 2015 Apr 15;475:32-9. doi: 10.1016/j.ab.2015.01.011. Epub 2015 Jan 27.
A "turn off-on" switch mode was established by using the interaction between acridine orange (AO) and DNA as an input signal and using the room temperature phosphorescence (RTP) reversible change of 3-mercaptopropionic acid (MPA)-capped Mn-doped ZnS quantum dots (QDs) as an output signal in biological fluids. AO was absorbed into the surface of Mn-doped ZnS QDs via electrostatic attraction and, thus, formed a ground-state complex through photoinduced electron transfer (PIET). This complex quenched the phosphorescence of Mn-doped ZnS QDs and then rendered the system into the "turn-off" mode. Along with the addition of DNA and embedded binding with DNA, AO was competitively induced to fall off from the surface of Mn-doped ZnS QDs and embed into the double helix structure of DNA. As a result, the RTP of Mn-doped ZnS QDs was recovered and the system consequently was rendered into "turn-on" mode. In this case, a new biosensor for DNA detection was built and has a detection limit of 0.033mgL(-1) and a detection range from 0.033 to 20mgL(-1). What is more, this kind of biosensor does not require complex pretreatments and is free from the interference from autofluorescence and scattering light. Thus, this biosensor can be used to detect DNA in biological fluids.
通过利用吖啶橙（AO）与DNA之间的相互作用作为输入信号，并利用巯基丙酸（MPA）包覆的锰掺杂硫化锌量子点（QDs）的室温磷光（RTP）可逆变化作为生物流体中的输出信号，建立了一种“关-开”开关模式。AO通过静电吸引被吸收到锰掺杂硫化锌量子点的表面，从而通过光诱导电子转移（PIET）形成基态复合物。这种复合物淬灭了锰掺杂硫化锌量子点的磷光，进而使系统进入“关断”模式。随着DNA的加入以及与DNA的嵌入结合，AO被竞争性地诱导从锰掺杂硫化锌量子点的表面脱落并嵌入DNA的双螺旋结构中。结果，锰掺杂硫化锌量子点的RTP得以恢复，系统因此进入“开启”模式。在这种情况下，构建了一种用于DNA检测的新型生物传感器，其检测限为0.033mgL(-1)，检测范围为0.033至20mgL(-1)。此外，这种生物传感器不需要复杂的预处理，并且不受自发荧光和散射光的干扰。因此，这种生物传感器可用于检测生物流体中的DNA。
