title: Thiol modified chitosan self-assembled monolayer platform for nucleic acid biosensor.
abstract: A self-assembled monolayer (SAM) of thiol modified chitosan (SH-CHIT), with thioglycolic acid (TGA) as a modifier to bestow thiol groups, has been prepared onto gold (Au)-coated glass plates for fabrication of the nucleic acid biosensor. The chemical modification of CHIT via TGA has been evidenced by Fourier transform infrared spectroscopy (FT-IR) studies, and the biocompatibility studies reveal that CHIT retains its biocompatible nature after chemical modification. The electrochemical studies conducted onto SH-CHIT/Au electrode reveal that thiol modification in CHIT amino end enhances the electrochemical behavior indicating that it may be attributed to delocalization of electrons in CHIT skeleton that participates in the resonance process. The carboxyl group modified end of DNA probe has been immobilized onto SH-CHIT/Au electrode using N-ethyl-N'-(3-dimethylaminopropyl)carbodimide (EDC) and N-hydroxysuccinimide (NHS) chemistry for detection of complementary, one-base mismatch and non-complementary sequence using electrochemical and optical studies for Mycobacterium tuberculosis detection. It has been found that DNA-SH-CHIT/Au bioelectrode can specifically detect 0.01 μM of target DNA concentration with sensitivity of 1.69 × 10(-6) A μM(-1).
authors.affiliation: Amity Institute of Applied Sciences, Amity University, Noida, Uttar Pradesh, India.
authors.forename: Maumita Das
authors.initials: MD
authors.lastname: Mukherjee
authors.forename: Pratima R
authors.initials: PR
authors.lastname: Solanki
authors.forename: Gajjala
authors.initials: G
authors.lastname: Sumana
authors.forename: Takaaki
authors.initials: T
authors.lastname: Manaka
authors.forename: Mitsumasa
authors.initials: M
authors.lastname: Iwamoto
authors.forename: Bansi D
authors.initials: BD
authors.lastname: Malhotra
mesh_terms: D015374:Biosensing Techniques; D048271:Chitosan / Q000737:chemistry; D004247:DNA / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D006046:Gold / Q000737:chemistry; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000302:isolation & purification*; D017550:Spectroscopy, Fourier Transform Infrared; D013864:Thioglycolates / Q000737:chemistry; D014376:Tuberculosis / Q000175:diagnosis* / Q000235:genetics
chemical_list: D013864:Thioglycolates; D006046:Gold; C017487:2-mercaptoacetate; D004247:DNA; D048271:Chitosan