Key Laboratory of Analysis and Detection for Food Safety (Ministry of Education & Fujian Province), Department of Chemistry, Fuzhou University, Fuzhou 350108, China.
ACS Appl Mater Interfaces. 2011 Dec;3(12):4668-76. doi: 10.1021/am201087r. Epub 2011 Nov 22.
A facile and simple electrochemical immunoassay for ultrasensitive determination of streptomycin residues (STR) in food was designed by using nanogold-assembled mesoporous silica (GMSNs) as bionanolabels on a three-dimensional redox-active organosilica-functionalized sensing interface. To construct such a sensing interface, we initially synthesized organosilica colloids by using wet chemical method, and then utilized the prepared colloidal organosilica nanocomposites for the immobilization of monoclonal anti-STR antibodies on a glassy carbon electrode based on a sol-gel method. The bionanolabels were prepared based on coimmobilization of horseradish peroxidase (HRP) and STR-bovine serum albumin conjugates (STR-BSA) on the GMSNs. With a competitive-type immunoassay format, the assay toward STR analyte was carried out in pH 5.5 acetate acid buffer (ABS) by using redox-active organosilica nanocomposites as electron mediators, biofunctionalized GMSNs as traces, and hydrogen peroxide (H(2)O(2)) as enzyme substrate. Under optimal conditions, the reduction current of the electrochemical immunosensor decreased with the increase in STR level in the sample, and displayed a wide dynamic range of 0.05-50 ng mL(-1) with a low detection limit (LOD) of 5 pg mL(-1) at 3s(B). Intra- and interassay coefficients of variation were less than 8.7 and 9.3% for STR detection, respectively. In addition, the methodology was validated with STR spiked samples including honey, milk, kidney, and muscle, receiving a good correspondence with the results obtained from high-performance liquid chromatography (HPLC).
基于纳米金组装的介孔硅纳米粒子（GMSNs）作为生物纳米标签，构建了一种用于检测食品中链霉素（STR）残留的灵敏电化学免疫分析方法。首先，采用湿化学法合成了有机硅胶体，然后利用所制备的胶体有机硅纳米复合材料，通过溶胶-凝胶法在玻碳电极上固定单克隆抗 STR 抗体。生物纳米标签是基于辣根过氧化物酶（HRP）和 STR-牛血清白蛋白结合物（STR-BSA）共固定在 GMSNs 上制备的。在竞争型免疫分析模式下，以 pH 5.5 乙酸缓冲液（ABS）为检测介质，采用具有氧化还原活性的有机硅纳米复合材料作为电子媒介体，生物功能化的 GMSNs 作为示踪物，H2O2 作为酶底物，对 STR 分析物进行了检测。在最优条件下，电化学免疫传感器的还原电流随着样品中 STR 水平的增加而降低，检测范围为 0.05-50ng mL-1，检测限（LOD）为 5pg mL-1（3s(B)）。对于 STR 检测，批内和批间变异系数均小于 8.7%和 9.3%。此外，该方法还用于检测蜂蜜、牛奶、肾脏和肌肉等含有 STR 的加标样品，与高效液相色谱（HPLC）法的结果具有良好的一致性。
