Synthesis of 3D-coral like polyaniline nanostructures using reactive oxide templates and their high performance for ultrasensitive detection of blood cancer

Abstract

We report the synthesis of 3D coral like polyaniline nanostructures (PANI-NC), using in situ sacrificial oxidative template route. The coral-like nanostructures were developed as electrode materials for biosensing applications by depositing it electrophoretically onto indium tin oxide (ITO) coated glass substrates. These fabricated electrodes were characterized using various microscopic, and spectroscopic techniques which confirms the deposition of 3D PANI-NC on ITO electrode (PANI-NC/ITO). Electrochemical studies of the PANI-NC/ITO showed improved electron transfer behavior with a diffusion coefficient of 3.097 × 10−8 cm2/s and heterogeneous electron-transfer rate constant of 4.52 × 10−4 cm/s. Further, these electrodes were utilized for the immobilization of biotinylated DNA sequence (22 base pairs), identified from BCR–ABL fusion gene using avidin-biotin coupling. The electrochemical impedance spectroscopy analysis showed that the nucleic acid sensor exhibits a linear dynamic range from 10-6 M to 10-17 M of target DNA with a low detection limit (7 × 10−18 M). The high differentiation ability and specificity of the nucleic acid biosensor with various target DNA sequences (complementary, noncomplementary, one base mismatch and two base mismatch) and clinical samples of CML positive patients demonstrate its potential for clinical diagnostics.