A glassy carbon electrode was modified with a composite consisting of ferrocene imidazolium salts and hydroxy-functionalized graphene in a Nafion matrix. The electrode is shown to facilitate the reduction of oxygen to form the superoxide anion radical. Atomic force microscopy and electrochemical impedance spectroscopy were used to characterize the electrode. The in-situ production of superoxide anion was then studied with an analogue of methyl-Cypridina luciferin (also referred to as Vargulin). As a result, an electrochemiluminescence (ECL) based assay was developed for the improved determination of the activity of the enzyme superoxide dismutase (SOD). Under optimized conditions, the ECL based calibration plot is linear in the 0.5 to 6.5 U·mL−1 SOD activity range, with a 0.2 U·mL−1 detection limit (at a signal-to-noise ratio of 3).

A pre-column derivatization method was developed to analyze polyamidoamine (PAMAM) dendrimers. The fluorescein isothiocyanate (FITC) derivation method improved the retention of PAMAM dendrimers on the reversed-phase column of high performance liquid chromatography (RP-HPLC). The derivation benefited the UV-Vis detection of PAMAM, although the fluorescence of FITC was quenched by PAMAM dendrimers. The primary amine-terminated PAMAM dendrimers, generation 3 (PAMAM-NH2 (G3)), were quantitatively determined by UV-Vis spectroscopy over the concentration range of 10–80 μg mL−1, with the calibration curve expressed as A = 131.6C (μg mL−1) − 295.6 (R2 = 0.9901) and the detection limit of 2.7 μg mL−1. The binding ratio of FITC to PAMAM-NH2 (G3) was determined as 8:1 by liquid chromatography-electrospray ionization-ion trap mass spectrometry (LC-ESI-IT-MS).

In this paper, a novel solid state pH sensor was fabricated by anodization of titanium substrate electrode. The relationship between pH sensitivity and hydrophilicity or surface morphology of TiO2 film was investigated. Amorphous TiO2 nanotube has better pH response than anatase TiO2 nanotube. After being irradiated by ultraviolet light (UV), the potential response of the electrode modified by amorphous TiO2 nanotube was close to Nernst equation (59 mV/pH). SEM, XRD, and XPS were used to characterize electrodes. Possible mechanism was discussed by analyzing surface hydroxyl groups, crystal structure and hydrophilicity of the electrodes. The electrode has been used to detect some kinds of soft drinks and shows good response.

A new sonogenerated chemiluminescence (SCL) system has been developed to investigate the SCL behavior of acidinium ester (AE). The optimum parameters for this SCL system have also been investigated in detail. Under the optimum conditions, a typical SCL signal could be obtained in a mixture of DMF and alkaline water solutions with volume ratio of 3 : 2. According to electrospray ionization mass spectrometry and sonochemiluminescence emission spectra, SCL emission could be ascribed to the formation of N-methylacridone with a different mechanism from that in both the chemiluminescence and electrochemiluminescence reaction of acridinium ester. The acridinium ester has been used as a SCL probe for labeling of anti-human insulin guinea pig polyclonal antibody, and it was found that the concentration of AE-conjugated antibody was linear with the SCL intensity in the range of 0.15–0.75 ppb with a linear correlation coefficient of 0.9980.

The ability of diethylstilbestrol to enhance the chemiluminescence reaction of luminol–H2O2, catalyzed by tetrasulfonated cobalt phthalocyanine in an alkaline medium, has been exploited to develop a new flow injection chemiluminescence method for the determination of diethylstilbestrol. Under the optimum conditions, the linearity of the calibration graph for the determination of diethylstilbestrol was in the range from 1.00×10−7 to 4.00×10−6 mol/l. The assay was sensitive (the detection limit was 6.42×10−8 mol/l, S/N=3), reproducible (the relative standard deviation was 2.6%, n=11), and accurate (recovery up to 92%). The method has been successfully applied to the determination of diethylstilbestrol in the pharmaceutical formulations. Dienestrol and hexestrol were specifically alkylphenols, which are similar to diethylstilbestrol, could be detected by this method. Furthermore, the enhanced mechanism of estrogen-like compounds was also discussed in this paper.

A pre-column derivatization method was developed to analyze polyamidoamine (PAMAM) dendrimers. The fluorescein isothiocyanate (FITC) derivation method improved the retention of PAMAM dendrimers on the reversed-phase column of high performance liquid chromatography (RP-HPLC). The derivation benefited the UV-Vis detection of PAMAM, although the fluorescence of FITC was quenched by PAMAM dendrimers. The primary amine-terminated PAMAM dendrimers, generation 3 (PAMAM-NH2 (G3)), were quantitatively determined by UV-Vis spectroscopy over the concentration range of 10–80 μg mL−1, with the calibration curve expressed as A = 131.6C (μg mL−1) − 295.6 (R2 = 0.9901) and the detection limit of 2.7 μg mL−1. The binding ratio of FITC to PAMAM-NH2 (G3) was determined as 8:1 by liquid chromatography-electrospray ionization-ion trap mass spectrometry (LC-ESI-IT-MS).