Nanobiocomposite platform based on polyaniline-iron oxide-carbon nanotubes for bacterial detection.
The nanocomposite based on polyaniline (PANI)-iron oxide nanoparticles (nFe(3)O(4)) and multi walled carbon-nanotubes (CNT) has been fabricated onto indium tin oxide (ITO) coated glass plate via facile electrochemical synthesis of polyaniline in presence of nFe(3)O(4) (~20 nm) and CNT (20-80 nm in diameter). The results of transmission electron microscopic studies show evidence of coating of PANI and nFe(3)O(4) onto the CNT. The PANI-nFe(3)O(4)-CNT/ITO nanoelectrode has been characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy studies. The biotinylated nucleic acid probe sequence consisting of 20 bases has been immobilized onto PANI-nFe(3)O(4)-CNT/ITO nanoelectrode using biotin-avidin coupling. It is shown that the PANI-nFe(3)O(4)-CNT platform based biosensor can be used to specifically detect bacteria (N. gonorrhoeae) at minute concentration as low as (1×10(-19) M) indicating high sensitivity within 45 s of hybridization time at 298 K by differential pulse voltammetry using methylene blue as electroactive indicator. This bacterial sensor has also been tested with 4 positive and 4 negative PCR amplicons of gonorrhoea affected patient samples. The results of these studies have implications towards the fabrication of a handheld device for Neisseria gonorrhoeae detection that may perhaps result in a decrease in the human immunodeficiency virus infections.
Department of Science & Technology Centre on Biomolecular Electronics, Biomedical Instrumentation Section, National Physical Laboratory (Council of Scientific & Industrial Research), Dr. KS Krishnan Marg, New Delhi-110012, India.
Renu
R
Singh
Rachna
R
Verma
G
G
Sumana
Avanish Kumar
AK
Srivastava
Seema
S
Sood
Rajinder K
RK
Gupta
B D
BD
Malhotra
D000814:Aniline Compounds / Q000737:chemistry; D001360:Avidin / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation*; D001710:Biotin / Q000737:chemistry; D004563:Electrochemistry / Q000379:methods; D005290:Ferric Compounds / Q000737:chemistry; D006069:Gonorrhea / Q000175:diagnosis / Q000382:microbiology*; D006801:Humans; D008297:Male; D008839:Microelectrodes; D008855:Microscopy, Electron, Scanning; D053761:Nanocomposites / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009344:Neisseria gonorrhoeae / Q000235:genetics* / Q000302:isolation & purification; D009693:Nucleic Acid Hybridization / Q000379:methods; D012680:Sensitivity and Specificity; D017550:Spectroscopy, Fourier Transform Infrared; D017971:Tin Compounds / Q000737:chemistry; D014961:X-Ray Diffraction
D000814:Aniline Compounds; D005290:Ferric Compounds; D037742:Nanotubes, Carbon; D017971:Tin Compounds; C416807:polyaniline; D001360:Avidin; C000499:ferric oxide; D001710:Biotin; C045358:stannic oxide