CtrA gene based electrochemical DNA sensor for detection of meningitis

Electrochemical DNA sensor has been fabricated by immobilizing thiolated single stranded oligonucleotide (ssDNA) probe onto gold (Au) coated glass electrode for meningitis detection using hybridization with complementary DNA (CtrA) in presence of methylene blue (MB). These electrodes (ssDNA/Au and dsDNA/Au) have been characterized using atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FT-IR), electrochemical impedance spectroscopy (EIS) and cyclic voltammetric (CV) technique. The DNA/Au electrode can detect the complementary DNA in the range of 7-42 ng/mu l in 5 min (hybridization) with response time 60 s and electrode is stable for about 4 months when stored at 4 degrees C. The sensitivity of dsDNA/Au electrode is 115.8 mu A/ng with 0.917 regression coefficient (R). (C) 2009 Elsevier B.V. All rights reserved.