Reduction of Interference Response at a Hydrogen Peroxide Detecting Electrode Using Electropolymerized Films of Substituted Naphthalenes

The abilities of electropolymerized films formed from various substituted naphthalenes to prevent the oxidation of the plasma interferences ascorbate, acetaminophen, and urate at a hydrogen peroxide detecting platinum electrode are reported. Films prepared from 2,3-, 1,5-, and 1,8-diaminonaphthalene and 5-amino-1-naphthol were compared with films prepared from o-, m-, and p-phenylenediamine for their permselectivity and stability. The films were quick to prepare (15 min) and insulating. All films exhibited reduced permeability to hydrogen peroxide (except poly(o-phenylenediamine)) and interferences. Lowest permeabilties to hydrogen peroxide, ascorbate and acetaminophen were obtained with poly(2,3-diaminonaphthalene) (39 ± 16, 0.5 ± 0.1, and 0.2 ± 0.1%, respectively) and poly(5-amino-1-naphthol) (20 ± 10, 0.2 ± 0.1, and 0.2 ± 0.1%, respectively), although these films had longer response times to hydrogen peroxide (60 and 120 s, respectively). These films also had the highest permselectivities to hydrogen peroxide against the common interferences ascorbate and acetaminophen (>80 ± 40:1 and 250 ± 160:1 for poly(2,3-diaminonaphthalene) and >80 ± 35:1 and 100 ± 35:1 for poly(5-amino-1-naphthol)). The changes in permeabilities of these films were determined for 21 days, and while all films experienced some deterioration, the poly(substituted naphthalene) films maintained lower permeabilities to all species compared to the poly(phenylenediamine) films.