Graphene oxide-chitosan nanocomposite based electrochemical DNA biosensor for detection of typhoid

Anu Singh, Gaurav Sinsinbar, Meenakshi Choudhary, Veeresh Kumar, Renu Pasricha, H. N. Verma, Surinder P. Singh, Kavita Arora

Research output: Contribution to journalArticlepeer-review


Graphene oxide (GO)-Chitosan (CHI) nano-composite is employed for the development of DNA based electrochemical biosensor for diagnosis of typhoid. Biosensor has been prepared by covalent immobilization of Salmonella typhi specific 5′-amine labeled single stranded (ss) DNA probe on GO-CHI/ITO via glutaraldehyde. Differential pulse voltammetry (DPV) studies revealed good specificity and ability of ssDNA/GO-CHI/ITO biosensor to distinguish complementary, non-complementary and one base mismatch sequences. The ssDNA/GO-CHI/ITO biosensor showed detection range of 10 fM to 50 nM and LOD 10 fM within 60 s hybridization times for complementary sequence. Further, ssDNA/GO-CHI/ITO bioelectrode is able to detect complementary target present in serum samples with LOD of 100 fM at 25 C. The excellent performance of biosensor is attributed to large surface-to-volume ratio and good electrochemical activity of graphene oxide, and good biocompatibility of chitosan, which enhances the DNA immobilization and facilitate electron transfer between DNA and electrode surface (ITO).

Original languageEnglish (US)
Pages (from-to)675-684
Number of pages10
JournalSensors and Actuators, B: Chemical
StatePublished - 2013


  • Chitosan
  • DNA
  • Graphene oxide
  • Nano composite
  • Salmonella
  • Typhoid

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Instrumentation
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Electrical and Electronic Engineering
  • Materials Chemistry


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