Zinc oxide nanoparticles based microfluidic immunosensor applied in Congenital Hypothyroidism Screening

MARCO A. SEIA; SIRLEY V. PEREIRA; MARTIN FERNANDEZ BALDO; IRMA E. DE VITO; JULIO RABA; GERMÁN A. MESSINA

ANALYTICAL AND BIOANALYTICAL CHEMISTRY

SPRINGER HEIDELBERG

Lugar: HEIDELBERG; Año: 2014 p. 4677 - 4684

1618-2642

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 diagnostic through the thyrotropin (TSH) level measurement. To accomplish the determination of TSH, synthetized zinc oxide (ZnO) nanobeads (NBs) covered by chitosan (CH) ZnO-CH NBs were covalently attached to the central channel (CC) of the designed microfluidic device. These beads were employed as platform for anti-TSH monoclonal antibodies immobilization for specifically recognize and capture TSH in neonatal samples without any special pretreatment. Afterwards, the amount of this trapped hormone was quantified by 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 synthetized ZnO-CH NBs were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The calculated detection limits for electrochemical detection and the ELISA procedure were 0.00087 µUI mL-1 and 0.015µUI 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, reasonably good LOD was achieved. These above mentioned features make the system advantageous for routine clinical analysis adaptation.