中文摘要：

以NaBH4为还原剂,制备了金与铂物质的量比为49∶1的金铂纳米合金（GP）.用兔抗人绒毛膜促性腺激素抗体（RhCG）修饰AuPt获得了免疫纳米合金探针（GP-RhCG）.在pH 5.8磷酸氢二钠-柠檬酸缓冲溶液及KCl存在的条件下,GP-RhCG探针发生非特异性聚集,在590 nm处有一个较强的共振散射峰.当有人绒毛膜促性腺激素（hCG）存在时,聚集的GP-RhCG探针与hCG发生特异性结合,生成分散性较好的GP-RhCG-hCG免疫复合物,导致590 nm处共振散射峰强度降低.其共振散射峰强度降低值ΔI590 nm与hCG浓度在6.67～86.7 ng/mL范围内呈现良好线性关系.免疫反应液中形成的GP-RhCG-hCG免疫复合物对葡萄糖-铜（II）体系具有较强的催化作用,其产物在610 nm处有一较强共振散射峰.随着hCG浓度增大,形成的GP-RhCG-hCG复合物越多,其催化作用增强,610 nm处的共振散射峰增强.其共振散射峰增大值ΔI610 nm与hCG浓度在3.33～133 ng/mL范围内呈线性关系.

英文摘要：

In the presence of sodium citrate as stabilizer,a gold-platinum nanoalloy（GP） in the mole ratio of 49∶1 was prepared by using NaBH4as a reducing agent.The rabbit anti-human chorionic gonadotrophin antibody（RhCG） was labeled by the GP to obtain a stable immune GP probe（GP-RhCG） for the human chorionic gonadotrophin（hCG）.In a pH 5.8 NaH2PO4-citric acid buffer solution and in the presence of KCl,the GP-RhCG probe was aggregated un-specifically to big particles that exhibited a resonance scattering（RS） peak at 590 nm.When the hCG was added,the GP-RhCG probe combined specifically with the hCG to form a dispersed GP-RhCG-hCG immunocomplex that resulted in the RS intensity decreasing at 590 nm.The decreased RS intensity（ΔI590 nm） is linear with hCG concentration in the range of 6.67—86.7 ng/mL,with a detection limit of 3.7 ng/mL hCG.The immunocomplex exhibited a strong catalytic effect on the slow Cu2O particle reaction of glucose-Cu（II）,and the particles appeared a RS peak at 610 nm.When the hCG concentration increased in the immune reaction system,the immunocomplex concentration increased,and the catalytic product of Cu2O particles increased,which caused the enhancement of RS intensity at 610 nm.The increased intensity（ΔI610 nm） is linear with the hCG concentration in the range of 3.33—133 ng/mL,with a detection limit of 1.7 ng/mL hCG.In addition,the influence of foreign substances on the determination of hCG was examined.The results show that 150 times of L-aspartic acid,urea,BSA,glycine,Ca（II） and Zn（II）,50 times of L-lysine and L-cysteine,30 times of IgG and IgA,40 times of IgM did not interfered with the determination of 80 ng/mL hCG.This indicates that this method has good selectivity.The hCG content in the serum sample was analyzed by the GP RS method and GP-catalytic RS method,the results are agreement with those of the chemiluminescence experiments.Both RS methods are of some advantages including low-cost,simplicity,rapidity,high sensitivity and selectivity.