J. Saurina et al., POTENTIOMETRIC BIOSENSOR FOR LYSINE ANALYSIS BASED ON A CHEMICALLY IMMOBILIZED LYSINE OXIDASE MEMBRANE, Analytica chimica acta, 371(1), 1998, pp. 49-56
An enzymatic lysine electrode is developed for the potentiometric anal
ysis of lysine (Lys). This lysine biosensor consists of a chemically i
mmobilized lysine oxidase membrane attached to an all-solid-state ammo
nium electrode. In this system, the enzymatic degradation of lysine pr
oduces ammonia, which is then detected with the ammonium electrode. Th
e influence of immobilization conditions on the potentiometric respons
e and the lifetime of the electrode was studied. Under optimal conditi
ons, the relationship between the potentiometric response and the log
[Lys] was linear between 3x10(-5) and 10(-3) M, the sensitivity was 50
mV/decade, the repeatability 1.4%, and the response time t(95%) was 1
5 s. (C) 1998 Elsevier Science B.V, All rights reserved.