Electrochemical biosensing of influenza A subtype genome based on meso/macroporous cobalt (II) oxide nanoflakes-applied to human samples.

Meso/macroporous cobalt (II) oxide nanoflakes were electrodeposited in a one-step process in the presence of N-methylpyrrolidone. On the surface of nanoflakes, a specific single stranded DNA sequence from the genome of influenza A subtype was then immobilized to fabricate an electrochemical biosensor. Hybridization of the biosensor with complementary, non-complementary and base-mismatch sequences was electrochemically detected. The biosensor was also employed to detect complementary DNA of viral RNA in culture and human samples. The biosensor could detect the complementary sequence with a detection limit of 86.4 amol L-1 and a linear concentration range of 1.0 fmol L-1 to 1.0 nmol L-1. It also detected a complementary DNA sequence converted from viral RNA with a detection limit of 0.28 ng μL-1 in a linear concentration range of 0.5-10 ng μL-1. Low detection limit, simple method of preparation of the transducer and no needing any DNA strand modification and tag are the principal advantages of the biosensor.