The Characterization and Fabrication of Poly (3,4-ethylenedioxythiophene)Enzyme Based Biosensors.

Surface Science;Sum Frequency Generation Vibrational Spectroscopy;X-ray Photoelectron Spectroscopy;Poly (3;4-ethylenedioxythiophene);Materials Science and Engineering;Engineering;Macromolecular Science & Engineering

Spanninga, Sarah AnneLahann, Joerg ;

University of Michigan

关键词: Surface Science;    Sum Frequency Generation Vibrational Spectroscopy;    X-ray Photoelectron Spectroscopy;    Poly (3;    4-ethylenedioxythiophene);    Materials Science and Engineering;    Engineering;    Macromolecular Science & Engineering;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/77934/saspanni_1.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Surface characterization of poly(3,4-ethylenedioxythiophene) (PEDOT) based polymers utilizing sum frequency generation (SFG) vibrational spectroscopy and X-ray photoelectron spectroscopy (XPS) were carried out to determine the surface phenyl functional group orientation as well asto investigate PEDOT counter-ion affinity and the driving force determining counter-ion incorporation during electrochemical polymerization.The characterization culminated into the fabrication and characterization of PEDOT enzyme based biosensors.SFG was used to investigate the surface phenyl ring orientation differences between polystyrene, poly (sodium 4-styrenesulfonate) (PSSNa), and the PSSNa found in the PEDOT: PSSNa suspension.The variety of counter-ions probed during the XPS study included the poly-anions, PSSNa and poly (acrylic acid), and small anions such as citrates (C6H5O73-), carbonates (CO32-), thiosulfate (S2O32-), phosphates (H2PO4- and HPO42-), acetate (C2H3O2-), chloride (Cl-), bromides (Br-), perchlorates (ClO4-), and sodium p-toluenesulfonate (TosNa). In mixtures containing PSS with other anions, PSS was found to be the dominant PEDOT counter-ion due to its polymeric nature over TosNa, ClO4-, and Cl- anions, though Br- was also found to act as counter-ion.The general qualitative PEDOT counter-ion affinity trend amongst small anions (from strongest to weakest) follows: S2O32- > COO- (citrate), Br-, ClO4- > Cl-, COO- (acetate), CO32- > NO3- > H2PO4-/HPO42-. These results did not follow the Hofmeister Series rigidly, but some general trends such as the dominance of Br- and ClO4- in all mixtures not containing S2O32- were observed. Thiosulfate was found to be the dominating counter-ion in every mixture it was present in regardless of the anionic charge, cation, or anionic hydration. Functional PEDOT-based biosensors were fabricated using physical immobilization of the enzymes glucose oxidase (GOx), l-lactate dehydrodenase (LDH), Tyrosinase, and glutamate oxidase (GLOD) within a PEDOT matrix.The counter-ions used were either PSS, heparin, or the enzyme itself.XPS was used to verify enzyme entrapment, while electrochemical impedance spectroscopy, cyclic voltammetry, and chrono-amperometry were used to characterize the films. The minimum glucose concentration that was detected for GOx based sensors was found to be ~5x10-4 M.Enzyme entrapment was also proven with LDH, Tyrosinase, and chemically immobilized GLOD; however biosensor functionality could not be proven at this time.