Studies Of Catecholamines Catalyzed By Metallophthalocyanines

Catecholamines,which contain adrenaline,nordrenaline and dopamine,are a kind of impotant neurotransmitters and incretions in hunman organism.It is of great significance to detect catecholamine levels in plasma,urine and body fluid for diagnosis and treatment of diseases.Fiber optic biosensor is the latest development of biological detection technology.Fiber optic biosensor based on enzyme catalysis has been prosperously applied in many fields,such as environment monitoring,food engineering,clinical medicine,etc.Metallophthalocyanine has been attracted attention as metal coenzyme due to its steady chemical properties and excellent catalytic ability.In this paper,in order to solve the existing problems in clinical medicine detection and the fiber optic biosensor,the optimized sensing materials are used for the fiber optic biosensor.Biosensor based on fluorescence quenching is designed and constructed,and has successfully been used to detect the concentrations of adrenalin.In this paper,the systematic studies are conducted as following:First,five metallophthalocyanines(MPc) are synthesized and used to catalyze the oxidation of catecholamines(CAs).The influence factors of catalytic efficiency,such as catalytic time,the amount of MPc,the pH value of solution and temperature,have been investigated.Second,a novel fiber optic AD biosensor is designed and constructed using FePc as catalyzer,the performance of the novel biosensor is studied.The main conclusions are summarized as follows:1.MPc(M=Mn²⁺,Fe²⁺,Co²⁺,Ni²⁺,Cu²⁺) of high purity and good crystallinity are synthesized with phthalic anhydride and urea.The reaction time is shortened by using dimethylbenzene in place of high boiling point solvent,and it is easy to get the products.2.In phosphate buffer solution(PBS),all MPc could effectively catalyze the oxidation of CAs.The corresponding oxidation products are adrenochrome, noradrenchrome and melanin,respectively.The optimal conditions for the oxidation reaction of DA are pH 8.0 and the MPc amount of 1.00 mg/mL.The optimal temperatures are different for different MPc.The optimal temperature for MnPc and CuPc are 50℃and 60℃,respectively.FePc and CoPc have the same optimal temperature which is 55℃.Obvious catalysis of NiPc appears when temperature is above 50℃,and catalytic activity increase with the increase of temperature.For the oxidation reaction of AD and NA,the optimal catalytic conditions are namely:pH=8.0,T=55℃and the amout of MP is 1.00 mg/mL.MPc have the catalytic activity in order ofη_MnPc＞η_FePc＞η_NiPc＞η_CuPc＞η_CoPc. Although MnPc shows the best catalytic activity under the optimal catalytic conditions,FePc could be used in larger pH range.3.The performance of the fiber optic AD biosensor is investigated.The dissolved oxygen and AD content are evaluated by relative phase delayΔψ.In PBS with pH 7.4, a linear relationship betweenΔψand AD concentration is observed in the range of 2.0×10^-6～9.0×10^-5 mol/L,and the low limit of detection is 4.0×10^-7 mol/L.The biosensor has good stability and repeatability,and its response time is 10 min.