What is EFIRM?

EFIRM stands for electric field induced release and measurement. EFIRM is EZLife Bio’s core technology that detects the presence of DNA or other biomolecules. The steps involving EFIRM assay are:

  1. Capture probe immobilization: Allele specific conducting probes are first immobilized in a conducting polymer surface at the base of a 96-well gold electrode plate.
  2. Direct target capture: Patient sample in the form of saliva or plasma is mixed with detector probes and added directly to the well.
  3. Reporter enzyme hybridization: Anti-fluorescein antibody conjugated to horseradish peroxidase (HRP) is added.
  4. Electrochemical measurement: Signal amplification is performed by addition of 3,3’, 5, 5’- tetramethylbenzidine (TMB) substrate for horseradish peroxidase to cause the electrons to be drawn up through the gold electrodes and the current in units of nanoampere is measured for biomolecule detection.


How does EFIRM Work?

The EFIRM platform is actuated by an electrochemical control system that works in 96-parallel channels. This electrochemical control system connects to a gold electrode array with the footprint of a traditional microtiter plate.

EFIRM is actuated molecularly by coating the gold electrodes with a highly efficient conducting polymer method that allows for the rapid immobilization of DNA probes, antibodies, antigens, and other small molecules. These biomolecules are immobilized in such high amounts that they form a highly sensitive molecular capture layer. This conducting polymer layer is then combined with a pulsed electric field method and enzymatic electrochemical readout system, which an instrument reads at the nanoamp-scale, allowing for highly sensitive measurement of biomolecule levels.


What is EFIRM's impact on healthcare?


EFIRM as a liquid biopsy tool has been validated in numerous blinded clinical tests in the United States, Taiwan, and China. In these results, there was a >95% concordance between EFIRM liquid biopsy (saliva,plasma) and genotyping results from tissue based genotyping using traditional extraction and quantitative PCR results. These results suggest that EFIRM has potential to be a non-invasive, PCR-free, biopsy-free rapid solution for detecting mutations relating to lung cancer directly from biofluid. Streamlining of the testing process means faster results with greater affordability.

Selected Bibliography

Wei, F. et al. Electrochemical Sensor for Multiplex Biomarkers Detection. Clinical Cancer Research 15, 4446–4452 (2009).
Chen, T.-H., Wei, F. & Ho, C. M. Near-field ion flow for molecular scale manipulation. in 421–424 (IEEE, 2009). doi:10.1109/SENSOR.2009.5285472
Wei, F., Yang, J. & Wong, D. T. W. Detection of exosomal biomarker by electric field-induced release and measurement (EFIRM). Biosensors and Bioelectronics 44, 115–121 (2013).
Wei, F. et al. Noninvasive Saliva-based EGFR Gene Mutation Detection in Patients with Lung Cancer. American Journal of Respiratory and Critical Care Medicine 190, 1117–1126 (2014).
Chiang, S. H. et al. RNAPro•SAL: A device for rapid and standardized collection of saliva RNA and proteins. BioTechniques 58, 69–76 (2014).
Wei, F., Sun, B., Liao, W., Ouyang, J. & Sheng Zhao, X. Achieving differentiation of single-base mutations through hairpin oligonucleotide and electric potential control. Biosensors and Bioelectronics 18, 1149–1155 (2003).
Pu, D. et al. Evaluation of a novel saliva-based epidermal growth factor receptor mutation detection for lung cancer: A pilot study: Saliva-based EGFR mutation detection. Thoracic Cancer (2016). doi:10.1111/1759-7714.12350
Wei, F. et al. Electrochemical detection of low-copy number salivary RNA based on specific signal amplification with a hairpin probe. Nucleic Acids Res. 36, e65 (2008).
Wei, F. et al. Bio/Abiotic Interface Constructed from Nanoscale DNA Dendrimer and Conducting Polymer for Ultrasensitive Biomolecular Diagnosis. Small 5, 1784–1790 (2009).
Wei, F. & Ho, C.-M. Aptamer-based electrochemical biosensor for Botulinum neurotoxin. Analytical and Bioanalytical Chemistry 393, 1943–1948 (2009).
Wei, F. et al. Electric Field–Induced Release and Measurement Liquid Biopsy for Noninvasive Early Lung Cancer Assessment. The Journal of Molecular Diagnostics 20, 738–742 (2018).
Liao, W., Randall, B. A., Alba, N. A. & Cui, X. T. Conducting polymer-based impedimetric aptamer biosensor for in situ detection. Analytical and Bioanalytical Chemistry 392, 861–864 (2008).
Liao, W. & Cui, X. T. Reagentless aptamer based impedance biosensor for monitoring a neuro-inflammatory cytokine PDGF. Biosensors and Bioelectronics 23, 218–224 (2007).
Liao, W., Randall, B. A., Alba, N. A. & Cui, X. T. Conducting polymer-based impedimetric aptamer biosensor for in situ detection. Analytical and Bioanalytical Chemistry 392, 861–864 (2008).

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