|Electrochromic Immunosensor: Smart Chip for Visual Detection of Bacteria
|Paper ID : 1038-ICNS
Saba Ranjbar *1, Mohammad Amin Farahmand Nejad2, Claudio Parolo3, Saeed Shahrokhian4, Arben Merkoci3
1Department of Chemistry, Sharif University of Technology, Tehran 11155-9516, Iran
2Department of Chemistry, Sharif University of Technology, Tehran 11155-9516, Iran
3Nanobioelectronics and Biosensor Group, Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC, The Barcelona Institute of Science and Technology, Campus UAB, Bellaterra, 08193, Barcelona, Spain
4Department of Chemistry, Sharif University of Technology, Tehran 11155-9516, Iran‎ Institute for Nanoscience and Nanotechnology, Sharif University of Technology, Tehran, Iran
|Finding fast and reliable ways to detect pathogenic bacteria is crucial for addressing serious public health issues in clinical, environmental and food settings. Here, we present a novel assay based on the conversion of an electrochemical signal into a more convenient optical read out for the visual detection of E. Coli. Electropolymerizing polyaniline (PANI) on indium tin oxide screen-printed electrode (ITO SPE), we achieved not only the desired electrochromic behavior but also a convenient way to modify the electrode surface with antibodies. Applying a constant potential to the PANI-modified ITO SPE induces a change in their oxidation state, which in turn generates a color change on the electrode surface. The presence of E. Coli on the electrode surface increases the resistance in the circuit affecting the PANI oxidation states, producing a different electrochromic response. Using this electrochromic sensor, we could measure concentrations of E. Coli spanning four orders of magnitude with a limit of detection of 102 (CFU mL-1). In this work, we show that merging the sensitivity of electrochemistry with the user-friendliness of an optical read out can generate a new and powerful class of biosensors, with potentially unlimited applications in a variety of fields.
|Electrochromic immuonosensor; Polyaniline; Multicolour electrochromic behaviour; E. Coli O157:H7; Visual detection.
|Status : Abstract Accepted (Oral Presentation)