中文摘要：

在90 ℃水浴条件下，以粒径为10 nm的纳米金做晶种，用柠檬酸三钠还原硝酸银，制备了平均粒径为30 nm的（Au）核（Ag）壳纳米微粒，用高速离心纯化除去过量的柠檬酸三钠获得了较纯的（Au）核（Ag）壳纳米微粒。在pH 3.8的HAc-NaAc缓冲溶液中，Fe2＋催化H2O2反应产生的羟基自由基可氧化（Au）核（Ag）壳纳米微粒生成银离子。离心后，离心液中的银离子可用火焰原子吸收光谱法在328.1 nm波长处测量。随着H2O2浓度增大，离心液中银离子浓度增加，其吸光度值增加。H2O2浓度在2.64～42.24 μmol·L-1范围内与上清液中银离子的原子吸收值ΔA呈良好的线性关系，回归方程为ΔA=0.014c-0.013 1, 相关系数为0.998 4，检出限为0.81 μmol·L-1 H2O2。当用于水样中H2O2的测定，获得了满意的结果。

英文摘要：

The 10 nm gold nanoparticles were prepared by Frens procedure. Using tri-sodium citrate as reducer of AgNO3, and 10 nm gold nanoparticles as seed, the （Au）core（Ag）shell nanoparticles the size of about 30 nm were prepared at 90℃ for 10 rain. Then it was separated by centrifuge at 10000 r·min^-1 for 15 min to obtain pure （Au）core（Ag）shell nanoparticles. In pH 3. 8 sodium acetate-acetic acid buffer solution, hydroxyl free radical from Fenton reaction between Fe（ Ⅱ ）-H2O2 oxidized （Au） core（Ag）shell nanoparticles to form silver ions. The silver ions in the centrifugal solutions can be measured by flame atomic absorption spectrometry at 328. 1 nm. The silver ions in the centrifugal solutions increased with the H2O2 concentration increasing, and the absorption value at 328. 1 nm was enhanced linearly. The influence factors such as pH value, buffer solution volume, concentration of （Au）core（Ag） shell and Fe（ Ⅱ ）, reaction temperature and time, and centrifuging velocity and time were considered, respectively. Under the conditions of 0. 20 mL pH 3. 8 sodium acetate-acetic acid buffer solution, 50 uL of 2. 0 mmol·L^-1 FeSO4, 60 uL of 2.94×10^-4 mol·L^-1 （Au）core（Ag）shell nanoparticle solution, reaction time of 20 min at 60℃, and centrifugalization at 14 000 rpm for 10 min, the increased value △A is proportional to the H2O2 concentration （c） from 2. 64 to 42. 24umol·L^-1 , with a detection limit of 0. 81 umol·L^-1. The regress equation was △A =0. 014c-0. 013 1, with a coefficient of 0. 998 4. The effect of foreign substances such as 100-times glucose, Cu^2＋, Mg^2＋ , Ca^2＋ , 50-times urea, bovine serum albumin, Mn^2＋, Pb^2＋ , and 30-times Cr^3＋ on the determination of 13. 2 umol·L-1 H2O2 was examined respectively, with a relative error of ±10%. Results showed that there was no interference. This assay showed high sensitivity and good selectivity for quantitative determination of H2O2 in waste water samples, with satisfactory results. The anal