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Electroaddressable Selective Functionalization of Electrode Arrays: Catalytic NADH Detection Using Aryl Diazonium Modified Gold Electrodes
Author(s) -
Harper Jason C.,
Polsky Ronen,
Dirk Shawn M.,
Wheeler David R.,
Brozik Susan M.
Publication year - 2007
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200703867
Subject(s) - surface modification , electrode , electrochemistry , electron transfer , nitro , chemistry , pyrroloquinoline quinone , catalysis , kinetics , chemical modification , adsorption , electrocatalyst , combinatorial chemistry , inorganic chemistry , materials science , photochemistry , polymer chemistry , organic chemistry , cofactor , enzyme , alkyl , physics , quantum mechanics
We report the application of 4‐nitrophenyl diazonium modified electrodes towards the electrochemical detection of NADH. Selective activation of individual electrodes on a 5 element array by electro‐addressable conversion of nitro groups to amines and subsequent EDC/NHS crosslinking to the NADH oxidant, pyrroloquinoline quinone (PQQ), is demonstrated. Inactivated electrodes retained nitro functionality and were protected against non‐specific adsorption and mild chemical reactions. Electrodeposition conditions were used to control nitrophenyl film thickness and showed that while increased film thickness leads to greater functionalization density of PQQ, it also results in decreased electron transfer kinetics. The electrodeposition protocol can therefore serve as a method to control electrode functionalization density and film electron transfer kinetics. We believe this simple technique for selective electrode functionalization may facilitate the development of next generation multianalyte electrochemical sensors.