Isomeric Effect of Mercaptobenzoic Acids on the Preparation and Fluorescent Properties of Copper Nanoclusters

• Main Authors: Yi-Jyun Lin, 林羿君
• Other Authors: Huan-Tsung Chang
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/75094121934857790910

碩士 === 國立臺灣大學 === 化學研究所 === 103 === An one-pot approach has been developed to synthesize copper nanoclusters (Cu NCs) aggregates from copper nitrate and mercaptobenzoic acid (MBA) at 70 °C within 30 min. Cu NCs prepared separately from the three isomers of MBA exhibit different physical and optical properties. 2-Mercaptobenzoic acid (thiosalicylic acid, TA) and 4-mercaptobenzoic acid (4-MBA) allow preparation of blue- and red-emissive Cu NCs aggregates when excited at 338 and 324 nm, with quantum yields of 13.2% and 0.5%, respectively. On the other hand, Cu NCs aggregates prepared from 3-mercaptobenzoic acid (3-MBA) have very weak red-emission properties. Upon increasing pH values from 3.0 to 11.0, the fluorescence intensity of TA-Cu NCs and 4-MBA-Cu NCs aggregates increases and decreases, respectively. Unlike TA-Cu NCs aggregates, 4-MBA-Cu NCs aggregates show strong aggregation-induced emission. The water-dispersible, stable, and highly fluorescent TA-Cu NCs aggregates allow detection of CNˉ down to 5 nM, based on analyte-induced fluorescence quenching.