Journal of Analytical & Bioanalytical Techniques
Open Access

Abstract

We report here the development of electrochemical DNA hybridization biosensor for detection of Salmonella typhimurium. Two types of DNA probes (biotin labeled and amine labeled) specific to S. typhimurium have been immobilized onto the carbon nanotube-polyaniline composite films (CNT-PANI) coated onto indium tin oxide (ITO) glass plates. The fabricated bioelectrodes (biotin-DNA/CNT-PANI/ITO electrode and NH 2 -DNA/CNT-PANI/ITO electrodes) have been characterized using electrochemical techniques, fourier-transform-infra red spectroscopy (FT-IR) and scanning electron microscopy (SEM). These Biotin-DNA/CNT-PANI/ITO electrode and NH 2 -DNA/CNT-PANI/ITO electrodes have been utilized to detect hybridization with complementary, non-complementary and one-base mismatch sequences using methylene blue (MB) as electroactive indicator. Results indicate that the NH2-DNA/CNT-PANI/ITO electrode has better detection limit (0.1 attomole) over the biotin- DNA-CNT-PANI/ITO electrode (0.5 attomole) within 30 seconds as compared to 35 seconds for biotin-DNA-CNT-PANI/ITO electrode. The NH 2 -DNA/CNT-PANI/ITO electrode has the capability to detect the hybridization with complementary sequences in genomic DNA of S. typhimurium within 60 seconds.

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