中文摘要：

利用纳米金（AuNPs）和L-半胱氨酸（Cys）修饰金电极（AuE）,得到对Cu^2＋具有灵敏响应的电化学修饰电极（Cys/AuNPs/AuE）。在Cu^2＋存在时对头孢氨苄进行水解,通过方波伏安法测定水解液中剩余Cu^2＋的浓度,从而间接测得头孢氨苄的含量。对金电极的修饰条件、头孢氨苄的水解条件等进行了优化。在pH 4.5的HAc-NaAc缓冲液中,头孢氨苄在Cu^2＋存在时于沸水浴中水解25 min后,溶液中剩余Cu^2＋在Cys/AuNPs/AuE上有良好的电化学响应,还原峰电流差与头孢氨苄的浓度分别在0.0058~0.12μmol/L和0.12~2.9μmol/L范围内呈良好的线性关系,检出限为1.9 nmol/L（S/N=3）。用本方法对鸡肉样品中的头孢氨苄残留进行测定,结果表明,本方法简便快速、灵敏度高,适用于鸡肉等食品样品中头孢氨苄残留的测定。

英文摘要：

A sensitive electrochemical modified electrode （ Cys/AuNPs/AuE ） to Cu（Ⅱ） was fabricated by immobilizing gold nanoparticles （ AuNPs ） and L-cysteine （ Cys ） on the surface of gold electrode （ AuE ） . Cephalexin was hydrolyzed in the presence of Cu（Ⅱ）, then the cephalexin concentration was obtained indirectly by using square wave voltammetry to detect the remaining Cu（Ⅱ） in hydrolysate. The modified conditions of AuE and hydrolytic conditions of cephalexin were optimized. When cephalexin was hydrolyzed in HAc-NaAc buffer solution （pH 4. 5） with Cu（Ⅱ） at 100℃ for 25 min, the remaining Cu（Ⅱ） in hydrolysate showed good electrochemical response on Cys/AuNPs/AuE. The difference of reductive peak currents had good linear relationships with cephalexin concentration in the range of 0. 0058-0. 12 μmol/L and 0. 12-2. 9 μmol/L, respectively. The detection limit was 1. 9 nmol/L based on the signal to noise ratio of 3. The proposed method was applied to detect cephalexin residue in chicken sample. The results showed that this method was simple, rapid, high sensitive, and suitable for the determination of cephalexin residue in chicken and other food samples.