Human sensor-inspired supervised machine learning of smartphone-based paper microfluidic analysis for bacterial species classification

Sangsik Kim, Min Hee Lee, Theanchai Wiwasuku, Alexander S. Day, Sujittra Youngme, Dong Soo Hwang, Jeong Yeol Yoon

Research output: Contribution to journalArticlepeer-review

26 Scopus citations


Bacteria identification has predominantly been conducted using specific bioreceptors such as antibodies or nucleic acid sequences. This approach may be inappropriate for environmental monitoring when the user does not know the target bacterial species and for screening complex water samples with many unknown bacterial species. In this work, we investigate the supervised machine learning of the bacteria-particle aggregation pattern induced by the peptide sets identified from the biofilm-bacteria interface. Each peptide is covalently conjugated to polystyrene particles and loaded together with bacterial suspensions onto paper microfluidic chips. Each peptide interacts with bacterial species to a different extent, leading to varying sizes of particle aggregation. This aggregation changes the surface tension and viscosity of the liquid flowing through the paper pores, altering the flow velocity at different extents. A smartphone camera captures this flow velocity without being affected by ambient and environmental conditions, towards a low-cost, rapid, and field-ready assay. A collection of such flow velocity data generates a unique fingerprinting profile for each bacterial species. Support vector machine is utilized to classify the species. At optimized conditions, the training model can predict the species at 93.3% accuracy out of five bacteria: Escherichia coli, Staphylococcus aureus, Salmonella Typhimurium, Enterococcus faecium, and Pseudomonas aeruginosa. Flow rates are monitored for less than 6 s and the sample-to-answer assay time is less than 10 min. The demonstrated method can open a new way of analyzing complex biological and environmental samples in a biomimetic manner with machine learning classification.

Original languageEnglish (US)
Article number113335
JournalBiosensors and Bioelectronics
StatePublished - Sep 15 2021


  • Bacteria identification
  • Biofilm
  • Biointerface
  • Paper microfluidic chip
  • Pathogen
  • Support vector machine (SVM)

ASJC Scopus subject areas

  • Biotechnology
  • Biophysics
  • Biomedical Engineering
  • Electrochemistry


Dive into the research topics of 'Human sensor-inspired supervised machine learning of smartphone-based paper microfluidic analysis for bacterial species classification'. Together they form a unique fingerprint.

Cite this