Seia Marco A, Pereira Sirley V, Fernández-Baldo Martin A, De Vito Irma E, Raba Julio, Messina Germán A
INQUISAL, Department of Chemistry, National University of San Luis, CONICET, Chacabuco 917. D5700BWS, San Luis, Argentina.
Anal Bioanal Chem. 2014 Jul;406(19):4677-84. doi: 10.1007/s00216-014-7882-9. Epub 2014 Jun 8.
In this article, we present an innovative approach for congenital hypothyroidism (CHT) screening. This pathology is the most common preventable cause of mental retardation, affecting newborns around the world. Its consequences could be avoided with an early diagnosis through the thyrotropin (TSH) level measurement. To accomplish the determination of TSH, synthesized zinc oxide (ZnO) nanobeads (NBs) covered by chitosan (CH), ZnO-CH NBs, were covalently attached to the central channel of the designed microfluidic device. These beads were employed as platform for anti-TSH monoclonal antibody immobilization to specifically recognize and capture TSH in neonatal samples without any special pretreatment. Afterwards, the amount of this trapped hormone was quantified by horseradish peroxidase (HRP)-conjugated anti-TSH antibody. HRP reacted with its enzymatic substrate in a redox process, which resulted in the appearance of a current whose magnitude was directly proportional to the level of TSH in the neonatal sample. The structure and morphology of synthesized ZnO-CH NBs were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The calculated detection limits for electrochemical detection and the enzyme-linked immunosorbent assay procedure were 0.00087 μUI mL(-1) and 0.015 μUI mL(-1), respectively, and the within- and between-assay coefficients of variation were below 6.31% for the proposed method. According to the cut-off value for TSH neonatal screening, a reasonably good limit of detection was achieved. These above-mentioned features make the system advantageous for routine clinical analysis adaptation.
在本文中，我们提出了一种用于先天性甲状腺功能减退症（CHT）筛查的创新方法。这种病症是智力发育迟缓最常见的可预防病因，影响着世界各地的新生儿。通过测量促甲状腺激素（TSH）水平进行早期诊断，可以避免其后果。为了实现TSH的测定，将壳聚糖（CH）包覆的合成氧化锌（ZnO）纳米珠（NBs），即ZnO-CH NBs，共价连接到所设计微流控装置的中央通道。这些珠子用作固定抗TSH单克隆抗体的平台，无需任何特殊预处理即可特异性识别和捕获新生儿样本中的TSH。之后，通过辣根过氧化物酶（HRP）偶联的抗TSH抗体对捕获的这种激素的量进行定量。HRP在氧化还原过程中与其酶底物反应，产生一种电流，其大小与新生儿样本中TSH的水平成正比。通过扫描电子显微镜（SEM）和X射线衍射（XRD）对合成的ZnO-CH NBs的结构和形态进行了表征。所提出方法的电化学检测和酶联免疫吸附测定程序的计算检测限分别为0.00087 μUI mL(-1)和0.015 μUI mL(-1)，批内和批间变异系数均低于6.31%。根据TSH新生儿筛查的临界值，实现了相当不错的检测限。上述这些特性使得该系统有利于适应常规临床分析。
