title: Sensitivity of diamond-capped impedance transducer to Tröger's base derivative.
abstract: Sensitivity of an intrinsic nanocrystalline diamond (NCD) layer to naphthalene Tröger's base derivative decorated with pyrrole groups (TBPyr) was characterized by impedance spectroscopy. The transducer was made of Au interdigitated electrodes (IDE) with 50 μm spacing on alumina substrate which were capped with the NCD layer. The NCD-capped transducer with H-termination was able to electrically distinguish TBPyr molecules (the change of surface resistance within 30-60 kΩ) adsorbed from methanol in concentrations of 0.04 mg/mL to 40 mg/mL. An exponential decay of the surface resistance with time was observed and attributed to the readsorption of air moisture after methanol evaporation. After surface oxidation the NCD cap layer did not show any leakage due to NCD grain boundaries. We analyzed electronic transport in the transducer and propose a model for the sensing mechanism based on surface ion replacement.
authors: Institute of Physics, Academy of Sciences of the Czech Republic, v.v.i., Cukrovarnická 10, 162 00, Prague 6, Czech Republic. stehlik@fzu.cz
authors: Stepan
authors: S
authors: Stehlik
authors: Tibor
authors: T
authors: Izak
authors: Alexander
authors: A
authors: Kromka
authors: Bohumil
authors: B
authors: Dolenský
authors: Martin
authors: M
authors: Havlík
authors: Bohuslav
authors: B
authors: Rezek
mesh_terms: D000327:Adsorption; D015374:Biosensing Techniques / Q000379:methods*; D003460:Crystallization; D018130:Diamond / Q000737:chemistry*; D058266:Dielectric Spectroscopy; D004553:Electric Conductivity; D017097:Electric Impedance; D004563:Electrochemistry / Q000379:methods; D004566:Electrodes; D004583:Electrons; D007477:Ions; D008027:Light; D000432:Methanol / Q000737:chemistry; D008956:Models, Chemical; D053758:Nanoparticles / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D013053:Spectrophotometry / Q000379:methods; D013499:Surface Properties
chemical_list: D007477:Ions; D018130:Diamond; D010100:Oxygen; D000432:Methanol