The interaction between Alizarin red（AR） and Chitosan（CS） was investigated in （0.1 mol/L） HAc-NaAc buffer solution（pH=4.5） on the glassy carbon electrode（GC） by cyclic and square wave voltammetry. The results show that both AR and AR-CS complex have a well-defined quasi-reversible redox wave(Vpc=-0.46 V, Vpa=-0.41 V) with adsorption characteristics. Electron transfer coefficient（α） and reaction rate constant（Ks） of AR and AR-CS were measured by cyclic voltammetry. The maximum binding numbers m between AR and CS was found to be 2 500. The experiment results confirmed that lower concentration of CS can enhance the detection sensitivity, while higher concentration of CS can lower the detection sensitivity. In the presence of 2.0×10-5 mol/L AR, the peak current of system are proportional to CS concentration in the range of 1.25×10-8～2.5×10-7 mol/L, and inversely proportional to CS concentration in the range of 2.5×10-7～1.25×10-5 mol/L, respectively. The binding interaction mechanism was also discussed.
