Abstract: FR-PO958
A Novel Conductive Polymer-Based Biosensor for Ultrasensitive Detection of Biomarkers in Lupus Nephritis
Session Information
- Pathology and Lab Medicine: Basic
November 08, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Pathology and Lab Medicine
- 1601 Pathology and Lab Medicine: Basic
Author
- Wu, Tianfu, University of Houston, Houston, Texas, United States
Background
Lupus is a systemic autoimmune disease that immune system can attack the organs and tissues, partiuclarly kidney causing highly mortality and co-morbidity. Unfortunately there is not a non-invasive diagnostic tool for lupus nephritis (LN). Recent studies have shown that urinary biomarkers are promising in LN diagnosis. However, since the concentration of biomarkers in urine sample is low, most the current assays are not optimial in detecting specific urinary biomarkers for LN due to their low sensitivity.
Methods
In this study, we developed a novel biosensor based on human thrombin aptamer-functionalized conductive gel-nanoparticle with poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) nanowires which could capture and concentrate low-abudant biomarkers, causing a binding-induced shrinkage of the gel nanoparticles, which could lead to a conductance change of the biosensor and subsequent signal amplification.
Results
By using Atomic-force microscopy (AFM), the topography and height profiles of the polymeric sensor were recorded and to analyze polymeric network shrinkage in response to PBS or Thrombin. Urinary thrombin levels were quantitatively analyzed through monitoring the conductance change caused by polymeric network shrinkage upon the aptamer-thrombin binding. A significant shrinkage of 18.14% of the biosensor was observed after biomarker recognition. The limit of detection (LOD) of the conductive gel-nanoparticle biosensor for human urine thrombin sample could reach 4.82× 10-16M. This thrombin-specific biosensor and a commercial human thrombin enzyme linked immunosorbent assay (ELISA) kit were used to perform side-by-side measurement of urinary thrombin in LN samples. The result obtained from the same patient using sensor or ELISA were used for pair test of correlation, and a strong correlation with a R2 value of 0.97 was found between the sensor and ELISA. The results indicate that this conductive gel-nanoparticle biosensor is highly sensitive and selective in accurately differentiate LN from healthy controls using urinary thrombin as a biomarker (P < 0.001).
Conclusion
Collectively, this novel ultrasensitive conductive gel-nanoparticle biosensor may hold promise in biomarker detection and diagnosis of LN.
Funding
- Other NIH Support