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

ABSTRACT

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.