Ultrasensitive and label-free biosensor for the detection of Plasmodium falciparum histidine-rich protein II in saliva

Sci Rep. 2019 Nov 25;9(1):17495. doi: 10.1038/s41598-019-53852-5.

Abstract

Malaria elimination is a global public health priority. To fulfil the demands of elimination diagnostics, we have developed an interdigitated electrode sensor platform targeting the Plasmodium falciparum Histidine Rich Protein 2 (PfHRP2) protein in saliva samples. A protocol for frequency-specific PfHRP2 detection in phosphate buffered saline was developed, yielding a sensitivity of 2.5 pg/mL based on change in impedance magnitude of the sensor. This protocol was adapted and optimized for use in saliva with a sensitivity of 25 pg/mL based on change in resistance. Further validation demonstrated detection in saliva spiked with PfHRP2 from clinical isolates in 8 of 11 samples. With a turnaround time of ~2 hours, the label-free platform based on impedance sensors has the potential for miniaturization into a point-of-care diagnostic device for malaria elimination.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Protozoan / analysis*
  • Biosensing Techniques / instrumentation
  • Diagnostic Tests, Routine
  • Electric Impedance
  • Humans
  • Malaria, Falciparum / diagnosis*
  • Miniaturization
  • Plasmodium falciparum / metabolism*
  • Point-of-Care Systems
  • Protozoan Proteins / analysis*
  • Saliva / parasitology*
  • Sensitivity and Specificity

Substances

  • Antigens, Protozoan
  • HRP-2 antigen, Plasmodium falciparum
  • Protozoan Proteins