Nanobiossensor eletroquímico preparado em uma única etapa para imunodiagnóstico

Biosensors are analytical devices that are composed of a biologic element and a transducer to enable the quick detection of analytes comprising pathologic agents, as instance. Hepatitis C is a liver disease caused by a flavivirus can cause both acute and chronic infection. Approximately 700 000 people die each year from hepatitis C-related liver diseases. Thus, analytical methodology for rapid screening of this disease is desirable. Methodologies that require a single step in the development of sensor platforms are a new and innovative trend, since they are easy mass production and result in more reliable, low cost and reproducible results [1, 2]. In the present work, a nanobiosensor was developed based on a nanocomposite of poly-ortho-phenylenediamine (PoPD) and carbon nanotube (CNT) obtained by electropolymerization through cyclic voltammetry at -0.8 to 0.8 V window potential at 0.02 V/s scan rate, during 10 cycles (Fig.1(a)). Anti-HCV antibodies were immobilized using by amide bonds with CNT after EDC/NHS activation. The synergism between CNT and PoPD improved the sensor surface conductivity (Fig.1(b)), increasing the electroactive area in 1,8times more than PoPD electrode surface, allowing the detection of lower fluctuations in the diffusion barrier, due to the antigen-antibody interactions. This 3D-nanostrutured electrode surface approach allowed new possibilities for immunosensors development that need a low limit of detection for serological diagnostic.