Synthesis of Quantum Dot / Boronic Acid-substituted Bipyridinium Salt Nanohybrids as Room-temperature Phosphorescence Probe for Fructose Detection / 分析化学

Trace level of fructose was successfully detected by a sensor, in which the phosphorescence of Mn-doped ZnS (Mn-ZnS) room-temperature phosphorescence (RTP) quantum dots (QDs) was used as signals, and boronic acid-substituted bipyridinium salt (BBV) synthesized from 2-(bromomethyl) phenylboronic acid and 4,4ˊ-bipyridyl was used as the receptor. The negatively-charged Mn-ZnS QDs and the positively-charged BBV electrostatically attracted each other to form Mn-ZnS QDs/ BBV nanohybrids, which quenched the RTP of Mn-ZnS QDs. After addition into these nanohybrids, the fructose bonded with BBV to form an anionic borate, which largely restricted the quenching of BBV on Mn-ZnS QDs, thus the RTP was restored. In this work, we investigated the effects of pH and reaction time on the RTP of the Mn-ZnS QDs/ BBV nanohybrids. Under the optimal conditions, the novel probe had a fructose detection limit of 0. 01 mmol/ L and a linear range of 0. 05-1. 0 mmol/ L was achieved with correlation coefficient of 0. 99. This phosphorescence sensor was superior with convenience and high speed, and can be potentially applied to the detection and analysis of fructose in foods and medicine fields.

Progress of Room Temperature Phosphorescent Sensing Application Based on Manganese-doped Zinc Sulfide Quantum Dots / 分析化学

In comparison with traditional organic dyes, semiconductor quantum dots ( QDs) feature a series of superior luminescence properties, including narrow and symmetric emission, broad excitation and strong absorption, excellent photobleaching-resistance, and good water solubility. The addition of dopants can endows QDs with extra new properties, e. g. , further increase the Stokes shift for avoiding self-quenching. Mn-doped ZnS QDs are a very representative example of doped QDs. No harmful elements such as Cd and Hg are involved in such type of bio-friendly QDs. Besides, the Mn2+dopant further adds QDs with excellent room temperature phosphorescence. Phosphorescent detection can effectively eliminate the interference of biological background fluorescence, thus Mn-doped ZnS QDs can be widely used in phosphorescent bioanalysis. In this paper, the recent progress of room temperature phosphorescence analysis with Mn-doped ZnS QDs was reviewed. The emphasis was placed on the several stimulative sensing design strategies, including the luminescence mechanism, ion probes, detection of small molecules and biomacromolecules.

Fabrication of IgG Functionalized Mn Doped ZnS Quantum Dots for Low Background Phosphorescent Sensing of IgG in Human Serum / 分析化学

IgG functionalized Mn doped ZnS quantum dots ( IgG-QDs ) were fabricated via the amide condensation between the carboxy groups on the surface of Mn doped ZnS quantum dots and the amino groups on the surface of IgG. The IgG antibody functionalized Au nanoparticals were synthesized via the electrostatic interaction between the Au nanoparticals and IgG antibody. Based on the fluorescence resonance energy transfer effect between the IgG-QDs and the IgG antibody functionalized Au nanoparticals, the IgG-QDs could be applied for low background phosphorescent sensing of IgG with the linear range of 1-10 μg/mL and the limit of detection of 0. 45 μg/mL. The proposed method was successfully applied to detect IgG in human serum without the disturbance of the background fluorescence and scattered light.