The Mimic Enzyme Activity Of Phthalocyanines And Its Application

Fiber optic biosensor based on enzyme catalysis is a big family of fiber optic sensor,and it has a wide application prospect in medical science,biological engineering,food industries and environment monitoring.But this kind of biosensor can only work in the presence of enzyme.And most time we use the nature enyzme to catalyze the substrate.So the study of the mimic enzyme used in the fiber optic epinephrine biosensor will contribute to overcome the disadvantage of the nature enzyme,such as their difficult extraction and purification,poor stability,and very limited source.Epinephrine is a crucial physiological neurotransmitter and is closely related to human health.As for the determination of epinephrine in the field of clinical diagnosis and biologic technology,a fiber optic biosensor is considered to be very necessary.So far,we have developed a novel fiber optic epinephrine biosensor based on laccase catalysis.The characters of the laccase influence the whole fiber optic biosensor greatly.Metallophthalocyanines(MPc),which have a perfect symmetrical 18-electron aromatic macrocycle,are easily accessible,very stable to degradation and cost effective.They could be studied and developed as an effective alternative to the nature enzyme.The work of this paper includes mainly four aspects as followed:(1)Four MPc(M=Mn^â…¡,Co^â…¡,Cu^â…¡,Ni^â…¡)have been prepared by the phthalic anhydride and urea.The composite were characterized by IR,FEG-SEM,XRD。The MPc we get have high purity and good crystallinity.(2)The activity of the four MPc was determined using 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid)(ABTS)as enzyme substrates.And their optimum reaction condition were studied.The optimal pH for the oxidation of ABTS catalyzed by MPc is 3.0 for all the four MPc in 1.0 mol/L Na₂HPO₄-citric acid buffer solution.The optimal catalytic temperature for all the four MPc is 40℃.Results showed that the four mimics enzyme had good activity,especially MnPc.(3)The oxidation of epinephrine catalyzed by MPc in different pH were studied. The optimal pH for the oxidation of epinephrine is 8.0 for all the four MPc in 1.0 mol/L Na₂HPO₄-citric acid buffer solution.The optimal catalytic temperature for all the four MPc is 55℃.The product was adrenaline-quinone at pH=8.0.This work provided a basis of epinephrine's detection in alkalescence.The mechanism of the adrenaline oxidation catalyzed by MPc was also studied.(4)A fiber optic epinephrine biosensor based on fluorescence quenching was designed and fabricated.The performance of this sensor in detecting epinephrine was investigated.