Towards the Commercialization of a Lab-on-a-Chip Device for Soil Nutrient Measurement

  • Georgios KokkinisEmail author
  • Guenther Kriechhammer
  • Daniel Scheidl
  • Bianca Wilfling
  • Martin Smolka
Conference paper
Part of the Communications in Computer and Information Science book series (CCIS, volume 953)


In this paper, we present a soil nutrient sensor based on the capillary electrophoresis chip technology. As a product intended for commercial use in soil nutrient analysis, we focused on the analysis of -NO3 and -SO4. The sensing core of the device is the microfluidic chip. The design of chip, adapted to the needs of a portable handheld device, hinders the flow of sample in the detection area - due to non-planarity of instalment or pressure differences - via a narrow injection channel. A known issue, is the injection discrepancies caused by chip-to-chip variances and overall ion strength, thus turning quantitative analysis into a challenge. We overcame this by adopting bromide as an internal standard. In order to discriminate bromide from ubiquitous chloride in soil samples we used polyvinylpyrrolidone (PVP) as a separation additive in our background electrolyte. An in-house algorithm was developed for the identification of the measurement peaks, consisting of a baseline smoothing and subtraction along with an optimized quantification of the area under the peaks and thus the ion concentration. For the detection of the ion concentration on-chip electrodes were utilized for a capacitively coupled conductivity measurement. Tests were performed with soil sample extractions from different regions and the results were cross-referenced with an ion chromatographer. The sensor’s response had to be corrected for different ions and it exhibited a second order polynomial response with an average absolute error of 5%.


Lab-on-a-chip Capillary electrophoresis Microfluidics Precision agriculture Soil analysis Nitrate sensor 


  1. 1.
    FAO: “World Fertilizer Trends and Outlook to 2018.” Food and Agriculture Organization of United Nations, 66 pages (2015)Google Scholar
  2. 2.
    Cordell, D., Drangert, J.-O., White, S.: The story of phosphorus: global food security and food for thought. Glob. Environ. Change 19, 292–305 (2009)CrossRefGoogle Scholar
  3. 3.
    Lawlor, D.W., Mengel, K., Kirkby, E.A.: Principles of plant nutrition. Ann Bot. 93(4), 479–480 (2004)CrossRefGoogle Scholar
  4. 4.
    Ceccotti, S.P.: Plant nutrient sulphur-a review of nutrient balance, environmental impact and fertilizers. In: Rodriguez-Barrueco, C. (ed.) Fertilizers and Environment, vol. 66, pp. 185–193. Springer, Dordrecht (1996). Scholar
  5. 5.
  6. 6.
    Sackmann, E.K., Fulton, A.L., Beebe, D.J.: The present and future role of microfluidics in biomedical research. Nature 507, 181 (2014)CrossRefGoogle Scholar
  7. 7.
    Whitesides, G.M.: The origins and the future of microfluidics. Nature 442, 368 (2006)CrossRefGoogle Scholar
  8. 8.
    Grossman, P.D., Colburn, J.C.: Capillary Electrophoresis: Theory and Practice. Academic Press, San Diego (2012)Google Scholar
  9. 9.
    Zemann, A.J.: Capacitively coupled contactless conductivity detection in capillary electrophoresis. Electrophoresis 24, 2125–2137 (2003)CrossRefGoogle Scholar
  10. 10.
    Huang, X., Luckey, J.A., Gordon, M.J., Zare, R.N.: Quantitative determination of low molecular weight carboxylic acids by capillary zone electrophoresis/conductivity detection. Anal. Chem. 61, 766–770 (1989)CrossRefGoogle Scholar
  11. 11.
    Rossier, J., Reymond, F., Michel, P.E.: Polymer microfluidic chips for electrochemical and biochemical analyses. Electrophoresis 23, 858–867 (2002)CrossRefGoogle Scholar
  12. 12.
    Zemann, A.J., Schnell, E., Volgger, D., Bonn, G.K.: Contactless conductivity detection for capillary electrophoresis. Anal. Chem. 70, 563–567 (1998)CrossRefGoogle Scholar
  13. 13.
    Smolka, M., Puchberger-Enengl, D., Bipoun, M., et al.: A mobile lab-on-a-chip device for on-site soil nutrient analysis. Precis. Agric. 18, 152–168 (2017). Scholar
  14. 14.
    Brito-Neto, J.G.A., Fracassi da Silva, J.A., Blanes, L., do Lago, C.L.: Understanding capacitively coupled contactless conductivity detection in capillary and microchip electrophoresis. Part 2. Peak shape, stray capacitance, noise, and actual electronics. Electroanalysis 17, 1207–1214 (2005)CrossRefGoogle Scholar
  15. 15.
    Breadmore, M.C.: Electrokinetic and hydrodynamic injection: making the right choice for capillary electrophoresis. Bioanalysis 1, 889–894 (2009)CrossRefGoogle Scholar
  16. 16.
    Eilers, P.H.C., Boelens, H.F.M.: Baseline correction with asymmetric least squares smoothing. Leiden University Medical Centre report. Leiden Univ Leiden, NL (2005)Google Scholar
  17. 17.
    Cao, W., Chen, X., Yang, X., Wang, E.: Discrete wavelets transform for signal denoising in capillary electrophoresis with electrochemiluminescence detection. Electrophoresis 24, 3124–3130 (2003)CrossRefGoogle Scholar
  18. 18.
  19. 19.
    McKeeman, W.M.: Algorithm 145: adaptive numerical integration by Simpson’s rule. Commun. ACM 5, 604 (1962)CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  • Georgios Kokkinis
    • 1
    • 2
    Email author
  • Guenther Kriechhammer
    • 1
  • Daniel Scheidl
    • 1
  • Bianca Wilfling
    • 1
  • Martin Smolka
    • 3
  1. 1.Pessl InstrumentsWeizAustria
  2. 2.TU WienViennaAustria
  3. 3.Joanneum Research FmbHWeizAustria

Personalised recommendations