Amperometric Sensing of Protocatechuic Acid with Polyaniline/Poly(Acrylic Acid) Composite Film Bearing Protocatechuate 3,4-Dioxygenase

作者：Kuwahara Takashi^*; Homma Toshimasa; Sumita Daiki; Kondo Mizuki; Shimomura Masato

来源：Kobunshi Ronbunshu, 2016, 73(2): 221-223.

DOI：10.1295/koron.2015-0076

• Biosensing
• Enzyme Electrode
• Polyaniline
• Protocatechuic Acid
• Protocatechuate 3,4-Dioxygenase
• (Received November 27, 2015, Accepted January 18, 2016, Advance Publication February 19, 2016)

Conducting composite films of polyaniline/poly(acrylic acid) were prepared by electrochemical polymerization of aniline in the presence of poly(acrylic acid). An enzyme electrode was fabricated with the composite film by covalently immobilizing protocatechuate 3,4-dioxygenase on its surface. Amperometric sensing of protocatechuic acid (PCA) was carried out with the enzyme electrode by monitoring 02 consumption accompanying enzymatic PCA oxidation. The sensing was conducted at an applied potential of -0.3 V vs. SCE in a phosphate buffer solution at pH 7.0. The current response was found to increase linearly with an increase in PCA concentration up to 0.55mM. The sensitivity was 155 mu A mM(-1) cm(-2) with the detection limit of 5 mu M. The enzyme electrode gave no response to phenolic compounds other than PCA and to electroactive species such as ascorbic acid and acetaminophen. This high selectivity can be attributed to the substrate specificity of protocatechuate 3,4-dioxygenase and the low potential for amperometry.

• 出版日期2016