盐酸克伦特罗快速检测胶体金试纸的研制

为建立快速检测猪尿等样品中盐酸克伦特罗（CL）的胶体金免疫层析方法，用柠檬酸三钠还原氯金酸制备了胶体金，将其标记抗CL单克隆抗体，制备了金标抗体；以CL-人血清白蛋白（HSA）为包被抗原、羊抗鼠IgG为质控线二抗，制成胶体金试纸。优化了胶体金颗粒粒径、标记抗体用量和pH值等各项参数，最终确定胶体金粒径为15 nm、每毫升胶体金溶液中添加20 ?g抗体、胶体金溶液pH值为7.4、金标抗体稀释液为添加0.1 %牛血清白蛋白（BSA）的0.05 mol/L磷酸盐缓冲液（pH 7.4）、金标抗体喷涂量为50 ?L/cm2、CL-HSA和羊抗鼠IgG的包被浓度分别0.5 mg/mL和2 mg/mL。研制的CL胶体金试纸检测限为3 ng/mL，与莱克多巴胺、沙丁胺醇等六种?-兴奋剂类药物无交叉反应。对42份猪尿样品的检测结果与市售酶联免疫（ELISA）试剂盒的符合率为100 %。试纸无需仪器辅助，操作简便，可在5 min内完成，适用于对CL残留进行现场检测。

Development of a Colloidal Gold Labeled Strip for the Rapid Detection of Clenbuterol

To develop colloidal gold immunochromatographic technique for the rapid detection of Clenbuterol (CL), colloidal gold was prepared by reduction of HAuCl4 using trisodium citrate. Anti-CL monoclonal antibodies (MAb) were then labeled with colloidal gold to obtain colloidal gold labeled MAb. The CL-human serum albumin (HSA) and goat anti-mouse IgG were immobilized on the lateral flow membrane to construct the strip. To obtain the best performance of the strip, several conditions were optimized as follows: the diameter of the colloidal gold particle 15 nm, the amount of MAb for labeling 20 ?g/mL, the pH value 7.4, the conjugate treating buffer 0.05 mol/L phosphate buffer (pH 7.4) containing 0.1% bovine serum albumin (BSA) and the thickness of colloidal gold-labeled CL antibody in use 50 ?L/cm2. In addition, the antigen and goat anti-mouse IgG were coated at 0.5 mg/mL and 2 mg/mL respectively. Under the optimum conditions, the limit of detection (LOD) of the strip was 3 ng/mL for swine urine. Cross-reaction tests showed that negligible cross-reactivity of the strip with six ?-Agonist compounds including ractopamine, salbutamol, etc. was detected. Forty-two samples of swine urine were detected by the developed strip and the results were confirmed by enzyme-linked immunosorbent assay (ELISA) kit. The accordance rate of the two methods was 100 %. The determination of CL by the strip did not need any instruments, and the total time for the determination of one sample was only 5 minutes. This method was applicable for the rapid determination of CL in the field.