Shen Guoli

Intercalation of Pharmorubicin Anticancer Drug to DNA Studied by Cyclic Voltammetry with Analytical Applications

ABSTRACT Variations of the cyclic voltammetric behavior of pharmorubicin in an aqueous medium upon addition of DNA were studied and utilized for the determination of DNA. It was observed that the redox waves of pharmorubicin after binding to the large and slowly diffusing DNA almost disappeared. The anodic peak currents of pharmorubicin, when the concentrations were fixed at 2.0 x 10−5 and 2.0 x 10−4 mol/L, decreased linearly correlated to the concentration of DNA added in the range of 0 - 30.7 and 0 - 260.3 μg/ml, with the detection limits of 1.2 and 20.8 μg/ml, respectively. The proposed method exhibited good recovery and reproducibility for the determination of DNA. Furthermore, the binding constant and binding site size of the pharmorubicin-DNA interaction were also calculated.

Polymer agglutination-based piezoelectric immunoassay for the determination of human serum albumin

Abstract Based on the detection of agglutination of antibody- or antigen-bearing polymer by an immunoreaction using a piezoelectric quartz crystal, a piezoelectric immunoassay technique was developed for the determination of human serum albumin (HSA). The effect of experimental conditions including the polymer concentration, the antibody dilution ratio and the reaction temperature on the frequency response were investigated. The frequency responses were linearly correlated to the concentrations of HSA in the range of 112 – 878 μg ml−1. Other antigens present in serum did not interfere significantly with the determination of HSA. Analytical results of five clinical specimens obtained using the developed technique were in satisfactory agreement with those given by the rate diffusion turbidimetry.

A sensitive nicotine sensor based on molecularly imprinted electropolymer of o-aminophenol

A sensitive nicotine sensor based on a molecularly imprinted electropolymer of o-aminophenol is proposed and its configuration and performance are studied in detail. On the condition of weak acidity, the sensitive layer was prepared by electropolymerization of o-aminophenol on a gold electrode in the presence of the template (nicotine). The sensor exhibits good selectivity and sensitivity to nicotine. The determination limit is 2.0×10−7 mol/L and a linear relationship between the current and concentration is found in the range of 4.0×10−7 ∼ 3.3 ×10−5 mol/L. The sensor has also been applied to the analysis of nicotine in tobacco samples with recovery rates ranging from 99.0% to 102%.