A Novel Electrochemical Method for Lentinan Determination Based on its Interaction with Medaylene Blue

This contribution proposed a novel electrochemical approach for lentinan (LT) determination using medaylene blue (MB) as probe. The interaction conditions of LT with MB were carefully studied by cyclic voltammetry. Under the optimum conditions, the cyclic voltammetric curve of MB showed a pair of convertible oxidation and deoxidization peaks with the peak potentials of -0.157 V and -0.191 V, respectively. After LT was mixed to the MB solution, the peak potential of MB was negatively moved weakly meanwhile the oxidation peak current decreased corresponding to the addition of LT, and consequently a novel method for LT determination was established. The liner equation between the decrease of current (∆ip) and LT concentration was obtained as ∆ip(μA)=1.00C(μg/mL)+5.50 (n=10,r=0.996). The linearity range and detectability (3σ) were 0.8~8.0 μg/mL and 0.45 μg/mL. The effects of coexisting materials on the new method were carefully studied and the detection results for LT injection sample were satisfactory. The interaction mechanism was also discussed.