title: Flexible nanoporous tunable electrical double layer biosensors for sweat diagnostics.
abstract: An ultra-sensitive and highly specific electrical double layer (EDL) modulated biosensor, using nanoporous flexible substrates for wearable diagnostics is demonstrated with the detection of the stress biomarker cortisol in synthetic and human sweat. Zinc oxide thin film was used as active region in contact with the liquid i.e. synthetic and human sweat containing the biomolecules. Cortisol detection in sweat was accomplished by measuring and quantifying impedance changes due to modulation of the double layer capacitance within the electrical double layer through the application of a low orthogonally directed alternating current (AC) electric field. The EDL formed at the liquid-semiconductor interface was amplified in the presence of the nanoporous flexible substrate allowing for measuring the changes in the alternating current impedance signal due to the antibody-hormone interactions at diagnostically relevant concentrations. High sensitivity of detection of 1 pg/mL or 2.75 pmol cortisol in synthetic sweat and 1 ng/mL in human sweat is demonstrated with these novel biosensors. Specificity in synthetic sweat was demonstrated using a cytokine IL-1β. Cortisol detection in human sweat was demonstrated over a concentration range from 10-200 ng/mL.
authors.affiliation: Department of Bioengineering, University of Texas at Dallas, 800 W. Campbell Road, EC 39, Richardson, TX 75080.
authors.forename: Rujuta D
authors.initials: RD
authors.lastname: Munje
authors.affiliation: Enlisense LLC, 1813 Audubon Pond Way, Allen, TX 75013.
authors.forename: Sriram
authors.initials: S
authors.lastname: Muthukumar
authors.affiliation: Department of Bioengineering, University of Texas at Dallas, 800 W. Campbell Road, EC 39, Richardson, TX 75080.
authors.forename: Anjan
authors.initials: A
authors.lastname: Panneer Selvam
authors.affiliation: Department of Bioengineering, University of Texas at Dallas, 800 W. Campbell Road, EC 39, Richardson, TX 75080.
authors.forename: Shalini
authors.initials: S
authors.lastname: Prasad
mesh_terms: D015374:Biosensing Techniques; D017097:Electric Impedance; D004581:Electronics / Q000295:instrumentation / Q000379:methods; D006801:Humans; D049329:Nanostructures / Q000737:chemistry; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods; D016062:Porosity; D015203:Reproducibility of Results; D013542:Sweat; D015034:Zinc Oxide / Q000737:chemistry
chemical_list: D015034:Zinc Oxide