A novel method of adrenaline concentration detection using fiber optical biosensor based on the catalysis of iron(II) phthalocyanine

摘要

As an effective alternative to the nature enzyme, metallophthalocyanine (MPc), having the advantages of easy accessibility, good stability and low cost, are used as catalyzer for the adrenaline (AD) oxidation. In this paper, the oxidation of AD by dioxygen using iron(II) phthalocyanine (FePc) as the catalyst was studied by electronic absorption spectra. The experimental results indicate that the oxidation product of AD catalyzed by FePc is adrenochrome with characteristic peaks at 298 ran and 267 nm. The catalytic activities of FePc are evaluated by the ratios of the absorbance at 298 nm of adrenochrome. The optimal concentration, pH and temperature for the oxidation of AD are 5.0×10~(-5) M, 8.0 and 55 ℃, respectively. By using lock-in technology, the fiber optic adrenaline biosensor based on FePc catalysis and fluorescence quenching was fabricated and studied. A linear relationship between φ, the phase delay of the sensor head, and AD concentration was observed in the range of 2.0×10~(-3) to 9.0×10~(-6) M and 2.0×10~(-5) to 9.0×10~(-5) M. The standard deviation (SD) values are 4.7×10~(-8) (n = 5) and 5.9×10~(-7) (n = 5) M, respectively, while the detection limit is 4.0×10~(-7) M. The biosensor has the response time of about 15 min and the preferred reproducibility and stability.