磁性量子点电致化学发光法测定李氏禾提取液中的过氧化氢

利用巯基乙酸水热法合成出表面修饰—COOH的CdTe量子点,并将CdTe量子点(QDs)连接在Fe3O4纳米粒子表面,制备出CdTe/Fe3O4磁性量子点。通过磁力将磁性量子点修饰于石墨电极表面。在pH7.5的PBS缓冲溶液中,H2O2可使CdTe量子点产生电致化学发光,H2O2浓度在4～100μmol/L范围内与CdTe量子点的电致化学发光强度呈良好的线性关系,检出限为0.24μmol/L。据此建立了测定样品中过氧化氢含量的电致化学发光分析法,并成功地应用于李氏禾草汁原液中过氧化氢含量的测定。该研究借助纳米Fe3O4的磁力特征,使敏感膜易于形成和更新分离,简化了实验操作,同时起到增强发光强度的作用。

Electrochemiluminescence Determination of Hydrogen Peroxide in Leersia hexandra Swartz Extracting Juice via Magnetic Quantum Dots

CdTe quantum dots(QDs) modified with —COOH on its′surface were synthesized by using mercaptoacetic acid hydrothermal synthesis,and QDs were connected to the Fe3O4 nanoparticles to prepare CdTe/Fe3O4 magnetic quantum dots.The magnetic quantum dots could be modified on the graphite electrode surface by magnetic force.In pH 7.5 PBS buffer solution,ECL of CdTe quantum dots can be generated by promotion of H2O2.There was a good linear relationship between ECL intensity and H2O2 concentration in the range of 4-100 μmol/L with a detection limit of 0.24 μmol/L.Based on this,an ECL method for the determination of hydrogen peroxide was established.The method was successfully applied in the determination of hydrogen peroxide concentration in Leersia hexandra Swartz extracting juice.With the aid of nano-Fe3O4 magnetic particles,the sensor could easily form and renewal the sensitive membrane by magnetic controlling.The experimental operation was simplified and the ECL intensity was improved significantly.