Abstract
The work demonstrates a simple method for sensitive detection of Ca2+ ion by electrochemical response of alizarin red S (ARS) and Ca-ARS at a gold nanoparticle modified glassy carbon electrode (GCE). In the 0.1 M KOH, a sensitive reduction peak was observed at −0.795 V at the gold nanoparticles modified electrode. The peak currents were proportional to the concentrations of Ca2+ ion in the range of 2.0 × 10−7 M–1.2 × 10−4 M. For the different pulse voltammetry (DPV) methods, the detection limit was 2.57 × 10−8 M. The reaction mechanism was primarily determined by cyclic voltammetry, and the experimental results showed that the electrode processes were quasireversible responses of ARS and irreversible responses of ARS-Ca. In addition, the method was simple, fast, precise, and was used in the determination of calcium in blood serum with satisfactory results.
Acknowledgments
This work was supported by the Natural Science Foundation of Shanxi Province, China (Grant No: 2009011055-3.).
Notes
a The concentration of Ca2+ in human serum was 2.36 × 10−3 M by ion selective electrode method in affiliated hospital of Changzhi Medical College.
b Mean of the three determinations.