Impedimetric paper-based biosensor for the detection of bacterial contamination in water

Saravanan Rengaraj, Alvaro Cruz-Izquierdo, Janet Scott, Mirella Di Lorenzo

Research output: Contribution to journalArticlepeer-review

102 Citations (SciVal)
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According to the World Health Organisation, worldwide waterborne diseases are responsible for nearly two million human deaths annually. Rapid and at-site screen of pathogenic microorganisms in drinking water can help to markedly reduce this number. Here we report an innovative, simple and low-cost, paper-based probe for detection of bacteria in water, fabricated by screen printing carbon electrodes onto hydrophobic paper. Electrochemical characterization of the printed electrodes confirmed fast-electron transfer, with an estimated electroactive surface area of 0.25 cm 2. The electrode surface was functionalised with carboxyl groups, prior to covalent immobilization of the lectin Concanavalin A (Con A), used as the biorecognition element. The system was then tested as an impedimetric sensor for bacteria in water. A linear increase in the probe charge transfer resistance was observed for bacterial concentrations ranging from 10 3 to 10 6 CFU mL −1, with an estimated lower detection limit of 1.9 × 10 3 CFU mL −1. Considering its remarkable simplicity, cost-effectiveness and biodegradability, the sensor here reported could be an attractive solution for portable testing kits that address the challenges of traditional time-consuming and expensive lab-based analyses.

Original languageEnglish
Pages (from-to)50-58
Number of pages9
JournalSensors and Actuators B: Chemical
Early online date7 Mar 2018
Publication statusPublished - 15 Jul 2018


  • Electrochemical impedance spectroscopy
  • Lectin-bacteria complex
  • Paper electronics
  • Screen printed electrode

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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