The ZnO quantum dots（QDs） were synthesized with improved chemical solution method.The size of the ZnO QDs is exceedingly uniform with a diameter of approximately 4.8 nm,which are homogeneously dispersed in ethanol.T...The ZnO quantum dots（QDs） were synthesized with improved chemical solution method.The size of the ZnO QDs is exceedingly uniform with a diameter of approximately 4.8 nm,which are homogeneously dispersed in ethanol.The optical absorption edge shifts from 370 nm of bulk material to 359 nm of QD materials due to the quantum size effect,while the photoluminescence peak shifts from 375 nm to 387 nm with the increase of the density of ZnO QDs.The stability of ZnO QDs was studied with different dispersion degrees at 0？C and at room temperature of 25？C.The agglomeration mechanisms and their relationship with the emission spectra were uncovered for the first time.With the ageing of Zn O QDs,the agglomeration is aggravated and the surface defects increase,which leads to the defect emission.展开更多
Nanohybrids were formed from 3-mercaptopropionic acid （MPA）-coated Mn-doped ZnS quantum dots （QDs） and methylene blue （MB） via electrostatic interaction, and then used in the detection of trace DNA. The principl...Nanohybrids were formed from 3-mercaptopropionic acid （MPA）-coated Mn-doped ZnS quantum dots （QDs） and methylene blue （MB） via electrostatic interaction, and then used in the detection of trace DNA. The principle of detection is as follows： MB binds with Mn-doped ZnS QDs via electrostatic interaction, and then quenches the room temperature phosphorescence （RTP） of the QDs through photoinduced electron-transfer （PIET）. After the addition of DNA, MB binds with DNA through intercalation and electrostatic interaction, and desorbs from the surfaces of Mn-doped ZnS QDs, which recovers the RTP of the QDs. On this basis, a DNA detection method based on the properties of RTP was set up. This method shows a detection range of 0.2-20 mg/L, and a detection limit of 0.113 mg/L. Since this method is based on the RTP of QDs, it is not interfered by the background fluorescence or scattering light in vivo, and thus, avoids complex sample pretreatment. Thus, this method is very feasible for detection of trace DNA in biofluids.展开更多
基金Project supported by the FRFCU(Grant No.2016JBM066)863 Program(Grant No.2013AA032205)+1 种基金the National Natural Science Foundation of China(Grant Nos.61575019,51272022,and 11474018)RFDP(Grant Nos.20120009130005 and 20130009130001)
文摘The ZnO quantum dots（QDs） were synthesized with improved chemical solution method.The size of the ZnO QDs is exceedingly uniform with a diameter of approximately 4.8 nm,which are homogeneously dispersed in ethanol.The optical absorption edge shifts from 370 nm of bulk material to 359 nm of QD materials due to the quantum size effect,while the photoluminescence peak shifts from 375 nm to 387 nm with the increase of the density of ZnO QDs.The stability of ZnO QDs was studied with different dispersion degrees at 0？C and at room temperature of 25？C.The agglomeration mechanisms and their relationship with the emission spectra were uncovered for the first time.With the ageing of Zn O QDs,the agglomeration is aggravated and the surface defects increase,which leads to the defect emission.
基金supported by the Fund for Construction Program of Chemical Advantage and Key discipline of Shanxi Province of China (No. 912019)
文摘Nanohybrids were formed from 3-mercaptopropionic acid （MPA）-coated Mn-doped ZnS quantum dots （QDs） and methylene blue （MB） via electrostatic interaction, and then used in the detection of trace DNA. The principle of detection is as follows： MB binds with Mn-doped ZnS QDs via electrostatic interaction, and then quenches the room temperature phosphorescence （RTP） of the QDs through photoinduced electron-transfer （PIET）. After the addition of DNA, MB binds with DNA through intercalation and electrostatic interaction, and desorbs from the surfaces of Mn-doped ZnS QDs, which recovers the RTP of the QDs. On this basis, a DNA detection method based on the properties of RTP was set up. This method shows a detection range of 0.2-20 mg/L, and a detection limit of 0.113 mg/L. Since this method is based on the RTP of QDs, it is not interfered by the background fluorescence or scattering light in vivo, and thus, avoids complex sample pretreatment. Thus, this method is very feasible for detection of trace DNA in biofluids.
