A Novel Sensitive Biosensor for Ca²⁺ Ion Based on Gold Nanoparticles Modified Electrode by Pulsed Electrodeposition

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.

Keywords:

• Alizarin red S
• Ca²⁺ ion
• Gold nanoparticles
• Pulsed electrodeposition

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.