STD sensor based on nucleic acid functionalized nanostructured polyaniline

STD (sexually transmitted disease, Gonorrhoea) sensor based on nucleic acid probe (from Opa, a multi-copy gene of Neisseria gonorrhoeae) functionalized nanostructured-polyaniline coated onto indium–tin-oxide-coated glass plate has been fabricated using avidin–biotin as cross-linking agent. This DNA functionalized electrode can specifically detect upto 0.5 × 10−15 M of complementary target within 60 s of hybridization time at 25 °C by differential pulse voltammetry (DPV) using methylene blue as electro-active DNA hybridization indicator. This highly sensitive and specific nucleic acid functionalized nanostructured-polyaniline electrode can distinguish presence of N. gonorrhoeae from Neisseria meningitidis and Escherichia coli culture and spiked samples from the urethral swabs of the patients.