Phosphorescent quantum dots/ethidium bromide nanohybrids based on photoinduced electron transfer for DNA detection

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Vol. 140; pp. 479 - 483
• Main Authors: Bi, Lin, Yu, Yuan-Hua
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 05.04.2015
• Subjects: DNA; DNA - analysis; DNA - urine; Electron Transport; Ethidium - chemistry; Humans; Limit of Detection; Luminescent Agents - chemistry; Luminescent Measurements - methods; Nanohybrids; Nanostructures - chemistry; Photoinduced electron transfer; Quantum Dots - chemistry; Quantum Dots - ultrastructure; Room-temperature phosphorescence; Nanohybrids; DNA; Photoinduced electron transfer; Room-temperature phosphorescence
• ISSN: 1386-1425; 1873-3557
• DOI: 10.1016/j.saa.2015.01.014

[Display omitted] •The high water-solubility Mn-doped-QDs with good RTP property was synthesized.•The RTP intensity of the QDs could be effectively quenched by EB.•EB can be selectively separated from the QDs by DNA.•The RTP of the QDs/EB nanohybrids was restored by DNA.•The DNA sensor was applied to biological fluids with satisfactory results. Mercaptopropionic acid-capped Mn-doped ZnS quantum dots/ethidium bromide (EB) nanohybrids were constructed for photoinduced electron transfer (PIET) and then used as a room-temperature phosphorescence (RTP) probe for DNA detection. EB could quench the RTP of Mn-doped ZnS QDs by PIET, thereby forming Mn-doped ZnS QDs/EB nanohybrids and storing RTP. Meanwhile, EB could be inserted into DNA and EB could be competitively desorbed from the surface of Mn-doped ZnS QDs by DNA, thereby releasing the RTP of Mn-doped ZnS QDs. Based on this mechanism, a RTP sensor for DNA detection was developed. Under optimal conditions, the detection limit for DNA was 0.045mgL−1, the relative standard deviation was 1.7%, and the method linear ranged from 0.2 to 20mgL−1. The proposed method was applied to biological fluids, in which satisfactory results were obtained.