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Highly Sensitive in vitro Biosensor for Enterotoxigenic Escherichia coli Detection Based on ssDNA Anchored on PtNPs‐Chitosan Nanocomposite
Author(s) -
Bansal Surbhi,
Jyoti Anurag,
Mahato Kuldeep,
Chandra Pranjal,
Prakash Rajiv
Publication year - 2017
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.201600169
Subject(s) - biosensor , dielectric spectroscopy , detection limit , cyclic voltammetry , nanocomposite , chitosan , escherichia coli , fourier transform infrared spectroscopy , materials science , carbon paste electrode , nuclear chemistry , electrode , chemistry , analytical chemistry (journal) , chromatography , electrochemistry , nanotechnology , chemical engineering , biochemistry , engineering , gene
Detection of Enterotoxigenic Escherichia coli in various biological samples has tremendous importance in human health. In this direction, we have designed a label free electrochemical biosensor for highly selective detection of Escherichia coli through detecting ST gene. The ability of sensor probe to detect ST G was confirmed using polymerase chain reaction. The biosensor was fabricated based on ST G specific probes immobilized on platinum nanoparticles chitosan nanocomposite on screen printed carbon electrode, which was characterized by cyclic voltammetry, transmission electron microscopy, and fourier transform infrared spectroscopy. A highly sensitive label free sensing was achieved by analyzing ST G hybridization using electrochemical impedance spectroscopy (EIS) technique. The EIS analysis showed a significant increase in charge transfer resistance after ST G interaction with the highly selective ssDNA probe immobilized on the nanocomposite film. The increase in charge transfer resistance was evaluated for varying concentrations of ST G , which shows a dynamic range between 1.0×10 −12 and 1.0×10 −4 with the detection limit of 3.6×10 −14 M (RSD<4.5 %). The regeneration of sensor probe was also studied and interference due to non‐target sequences was evaluated to ensure the selectivity of the designed sensor. The practical applicability of sensor probe was also analyzed by detecting the ST G from the bacteria present in surface water.