title: Zwitterionic phenyl layers: finally, stable, anti-biofouling coatings that do not passivate electrodes.
abstract: Organic coatings on electrodes that limit biofouling by proteins but are of sufficiently low impedance to still allow Faradaic electrochemistry to proceed at the underlying electrode are described for the first time. These organic coatings formed using simple aryl diazonium salts present a zwitterionic surface and exhibit good electrochemical stability. The layers represent a low impedance alternative to the oligo (ethylene glycol) (OEG)-based anti-biofouling coatings and are expected to find applications in electrochemical biosensors and implantable electrodes. Two different zwitterionic layers grafted to glassy carbon surfaces are presented and compared to a number of better-known surfaces, including OEG-based phenyl-layer-grafted glassy carbon surfaces and OEG alkanethiol SAMs coated on gold, to allow the performance of these new layers to be compared to the body of work on other anti-biofouling surfaces. The results suggest that phenyl-based zwitterionic coatings are as effective as the OEG SAMs at resisting the nonspecific adsorption of bovine serum albumin and cytochrome c, as representative anionic and cationic proteins at physiological pH, whereas the impedance of the zwitterionic phenyl layers are two orders of magnitude lower than OEG SAMs.
authors: School of Chemistry and Australian Centre for NanoMedicine, The University of New South Wales, Sydney, NSW 2052, Australia.
authors: Alicia L
authors: AL
authors: Gui
authors: Erwann
authors: E
authors: Luais
authors: Joshua R
authors: JR
authors: Peterson
authors: J Justin
authors: JJ
authors: Gooding
mesh_terms: D000327:Adsorption; D000818:Animals; D057219:Biofouling / Q000517:prevention & control*; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002244:Carbon / Q000737:chemistry; D002417:Cattle; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D004566:Electrodes; D004582:Electronics, Medical / Q000379:methods; D019855:Ethylene Glycol / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D008856:Microscopy, Fluorescence; D008956:Models, Chemical; D010767:Phosphorylcholine / Q000737:chemistry; D011506:Proteins / Q000737:chemistry; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry
chemical_list: D020099:Coated Materials, Biocompatible; D011506:Proteins; D013438:Sulfhydryl Compounds; D010767:Phosphorylcholine; D012710:Serum Albumin, Bovine; D002244:Carbon; D006046:Gold; D019855:Ethylene Glycol