Chinese Science Bulletin

, Volume 58, Issue 4, pp 440–448

Development of a novel conductance-based technology for environmental bacterial sensing

Open AccessInvited Article Environmental Chemistry

DOI: 10.1007/s11434-012-5621-1

Cite this article as:
Shen, F., Tan, M., Xu, H. et al. Chin. Sci. Bull. (2013) 58: 440. doi:10.1007/s11434-012-5621-1


In this study, a simple impedance based technology for measuring bacterial concentrations was developed. The measurement system includes the signal amplification, copper probes and a sample loader. During the experiments, the conductance of Bacillus subtilis var niger, Pseudomonas fluorescens, and Escherichia coli were measured using the combination of a pre-amplifier and a lock-in amplifier. The conductance data were modeled verses the bacterial concentrations. Results indicated that the relationship between the conductance of bacterial suspensions and their concentrations follows a generic model: \(Y = C_1 + C_2 \times e^{\left( { - X/C_3 } \right)}\), where Y is the conductance (S), X is the bacterial concentration (Number/mL: abbreviated to N/mL) for all species tested, and C1–3 are constants. Gram negative P. fluorescens and E. coli assumed similar conductance curves, which were flatter than that of gram positive B. subtilis var niger. For P. fluorescens and E. coli the culturing technique resulted in higher concentration levels (statistically significant) from 2 to 4 times that measured by the impedance based technology. For B. subtilis var niger, both methods resulted in similar concentration levels. These differences might be due to membrane types, initial culturability and the obtained conductance curves. The impedance based technology here was shown to obtain the bacterial concentration instantly, holding broad promise in realtime monitoring biological agents.


bacterial impedanceconductancebioaerosolbacterial concentrations
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Supplementary material

11434_2012_5621_MOESM1_ESM.pdf (409 kb)
Supplementary material, approximately 409 KB.

Copyright information

© The Author(s) 2013

Authors and Affiliations

  1. 1.State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and EngineeringPeking UniversityBeijingChina
  2. 2.College of Mechanical and Electrical EngineeringBeijing Union UniversityBeijingChina
  3. 3.Department of Reproductive HealthGuangdong Women and Children HospitalGuangzhouChina
  4. 4.South China Institute of Environmental ScienceMinistry of Environmental ProtectionGuangzhouChina