摘要
新的电子传递中间体α-萘甲酰尼罗蓝(NNB)能强烈吸附在石墨上以构成修饰电极,在-0.5V至+0.6V(vs.SCE)电位区内,固定化的NNB表现出相当可逆的氧化还原行为,总反应中有2个电子和2个质子参加,在pH7.0缓冲溶液中其表面标准电位E°′为—170mV,表观电子传递常数K_s为3s^(-1),NNB对还原辅酶NADH的电化学氧化有明显催化作用,可使氧化过电位降低550mV.NADH的电催化氧化遵循EC机理,催化反应步骤为速度决定步骤,其速度常数为3×10~3dm^3·mol^(-1)·S^(-1)。NNB在中性和弱碱性介质中的稳定性优于其它电子传递中间体,是有前途的电催化剂。
α-Naphthoyl Nile blue (NNB) is a new electron-transfer mediator, synthesized recently in our laboratory. It can be strongly adsorbed on graphite to make modified electrodes. The immobilized NNB exhibits relatively reversible redox behavior in the potental region from-0.5 to+0.6V (vs. SCE), 2 electrons and 2 protons taking part in the overall reaction. In pH 7.0 buffer solution the surface standard potential E°′ is-170mV, and apparent electron-txansfer rate constant k_s is 3s^(-1). NNB modified electrodes show significantly catalytic effects on electro-chemical oxidation of dihydrocoenzyme NADH, making oxidation overpotential decrease by 550mV. The electrecatalytic oxidation of NADH obeys EC mechanism, where catalytic reaction is rate-determining step with rate constant of 3×10~3 dm^3·mol^(-1)·s^(-1). In neutral and weakly basic solutions NNB is more stable than the other mediators, hence appears promising for practical applictions.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
1990年第1期33-37,共5页
Acta Chimica Sinica
基金
国家自然科学基金
