Simultaneous EQCM and diffuse reflectance UV-visible spectroelectrochemical measurements: poly(aniline-co-o-anthranilic acid) growth and property characterization.
Piezoelectric diffuse reflectance spectroelectrochemistry (PDRSEC), a new technique of diffuse reflectance spectroelectrochemistry (DRSEC) in combination with electrochemical quartz crystal microbalance (EQCM), was developed to study the electrochemical copolymerization of aniline and o-anthranilic acid in 1.0 mol l(-1) HClO4 and the properties of these copolymers. The DRSEC using an integral sphere was proven to possess a higher optical sensitivity at the unpolished piezoelectric quartz crystal electrodes used than the mirror reflectance spectroelectrochemistry mode. The copolymers grown from the copolymerization bath of different molar fractions of o-anthranilic acid (F1, relative to the total amount of the two monomers) showed intermediate properties between those of the homopolymers, which varied gradually with F1. The swelling/dissolution behavior of the copolymers vs solution pH was traced via the EQCM frequency and resistance signals, and its large dependence on F1 was found and discussed. In a HAc-NaAc buffer solution at pH 5.6, the amount of adsorbed lysozyme was found to be positively correlated with F1, via an EQCM impedance investigation, demonstrating the feasibility of using poly(aniline-co-o-anthranilic acid) as a load-adjustable immobilization matrix for cationic proteins. The novel PDRSEC method proposed is highly recommended for surface electrochemistry studies at relatively rough electrodes.
Jiang
Ling
L
Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research (Hunan Normal University), Ministry of Education, Hunan Normal University, Changsha 410081, People's Republic of China.
Xie
Qingji
Q
Yang
Ling
L
Yang
Xinyan
X
Yao
Shouzhuo
S
D000327:Adsorption; D004058:Diffusion; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D009113:Muramidase / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D013053:Spectrophotometry / Q000295:instrumentation / Q000379:methods*; D013997:Time Factors
D011108:Polymers; D006046:Gold; D009113:Muramidase