Novel chitosan/gold-MPA nanocomposite for sequence-specific oligonucleotide detection

• Published in: Carbohydrate polymers 2010-08, Vol.82 (1), p.189-194
• Main Authors: Cao, Shunsheng, Mishra, Rajeev, Pilla, Srikanth, Tripathi, Swapnil, Pandey, Manoj K., Shah, Gopit, Mishra, Ajay K., Prabaharan, Mani, Mishra, Shivani B., Xin, Jin, Pandey, R.R., Wu, Weiwei, Pandey, Avinash C., Tiwari, Ashutosh
• Format: Article
• Language: English
• Subjects: Application fields; Applied sciences; Biological and medical sciences; Biosensors; Biotechnology; Chitosan; DNA biosensor; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Methods. Procedures. Technologies; Nanocomposite electrode; Polymer industry, paints, wood; Sequence-specific detection; Technology of polymers; Thiol caped gold NPs; Various methods and equipments
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2010.04.051

A 20-mer single-stranded oligodeoxyribonucleotide (ssODNs) was covalently probed onto the nanocomposite electrode, made up of an indium-tin oxide (ITO) glass surface coated with chitosan (CHIT), which is bonded with carboxyl functionalized thiol capped gold nanoparticles (gold-mercaptopropionic acid, Au-MPA NPs). The prepared CHIT/Au-MPA/ITO and the ssODNs/CHIT/Au-MPA/ITO electrodes were characterized with FTIR spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and cyclic voltammetry (CV). TEM micrograph of the composite electrode showed that Au-MPA NPs had the diameter ranging from 4 to 16 nm. The ssODNs/CHIT/Au-MPA/ITO electrode showed a linear increase in the amperometric current with an increasing concentration of the single-stranded target complementary ODNs (cODNs) within the range of 0.03–325 fM. The ssODNs/CHIT/Au-MPA/ITO electrode exhibited a sensitivity of 0.572 μA/fM with a response time of 12 s. The ssODNs/CHIT/Au-MPA/ITO electrode had a shelf life of ∼182 days, when stored at 4 °C.