title: Conducting polymer-silk biocomposites for flexible and biodegradable electrochemical sensors.
abstract: Approaches to form flexible biosensors require strategies to tune materials for various biomedical applications. We report a facile approach using photolithography to fabricate poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (
  PSS) sensors on a fully biodegradable and flexible silk protein fibroin support. A benchtop photolithographic setup is used to fabricate high fidelity and high resolution
  PSS microstructures over a large (cm) area using only water as the solvent. Using the conductive micropatterns as working electrodes, we demonstrate biosensors with excellent electrochemical activity and stability over a number of days. The fabricated biosensors display excellent nonspecific detection of dopamine and ascorbic acid with high sensitivity. These devices are mechanically flexible, optically transparent, electroactive, cytocompatible and biodegradable. The benign fabrication protocol allows the conducting ink to function as a matrix for enzymes as shown by a highly sensitive detection of glucose. These sensors can retain their properties under repeated mechanical deformations, but are completely degradable under enzymatic action. The reported technique is scalable and can be used to develop sensitive, robust, and inexpensive biosensors with controllable biodegradability, leading to applications in transient or implantable bioelectronics and optoelectronics.
authors.affiliation: Department of Chemical and Life Science Engineering, Virginia Commonwealth University, 601 and 1001, W Main Street, Richmond, VA 23284, USA.
authors.forename: Ramendra K
authors.initials: RK
authors.lastname: Pal
authors.affiliation: Department of Chemistry, Virginia Commonwealth University, 601 and 1001, W Main Street, Richmond, VA 23284, USA.
authors.forename: Ahmed A
authors.initials: AA
authors.lastname: Farghaly
authors.affiliation: Department of Chemical and Life Science Engineering, Virginia Commonwealth University, 601 and 1001, W Main Street, Richmond, VA 23284, USA.
authors.forename: Congzhou
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Chemistry, Virginia Commonwealth University, 601 and 1001, W Main Street, Richmond, VA 23284, USA.
authors.forename: Maryanne M
authors.initials: MM
authors.lastname: Collinson
authors.affiliation: Department of Biotechnology, Indian Institute of Technology Kharagpur, West Bengal 721302, India.
authors.forename: Subhas C
authors.initials: SC
authors.lastname: Kundu
authors.affiliation: Department of Chemical and Life Science Engineering, Virginia Commonwealth University, 601 and 1001, W Main Street, Richmond, VA 23284, USA. Electronic address: vyadavalli@vcu.edu.
authors.forename: Vamsi K
authors.initials: VK
authors.lastname: Yadavalli
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000032:analysis; D001673:Biodegradation, Environmental; D015374:Biosensing Techniques / Q000295:instrumentation*; D012831:Bombyx / Q000737:chemistry*; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000737:chemistry*; D004298:Dopamine / Q000032:analysis; D004553:Electric Conductivity; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D005947:Glucose / Q000032:analysis; D018583:Pliability; D011108:Polymers / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry*; D047011:Silk / Q000737:chemistry*
chemical_list: D019086:Bridged Bicyclo Compounds, Heterocyclic; D004800:Enzymes, Immobilized; D011108:Polymers; D011137:Polystyrenes; D047011:Silk; C121383:poly(3,4-ethylene dioxythiophene); D005947:Glucose; D001205:Ascorbic Acid; D004298:Dopamine
keywords: Biosensor; Conducting polymer; Flexible; Photolithography; Silk protein