Platinum nanowire （PtNW） can be grown by electrodeposition in polycarbonate membrane, with the average diameter of the nanowires about 250 nm. The PtNW and multiwalled carbon nanotubes （CNT） are then dispersed into chitosan （CHIT） solution. The resulting PtNW-CNT-CHIT material brings new capabilities for electrochemical devices by using the synergistic action of the electrocatalytic activity of PtNW and CNT. By dropping the PtNW-CNT-CHIT film onto the glassy carbon （GO） electrode surface, and after evaporation an amperometric sensor for the determination of indole-3-acetic acid （IAA） was developed. The oxidation current of IAA increased significantly at the PtNW-CNT-CHIT film coated GC electrode, in contrast to that at the CNT-CHIT modified GC. The linear response of the sensor is from 50 ng/ml to 50 μg/ml with a detection limit of 25 ng/mL.
Ruo Zhong WANGLang Tao XIAOMing Hui YANGJun Hui DINGFeng Li QUGuo Li-SHEN
An impedance immunosensor based on O-phenylenediamine modified gold electrode for the determination of phytohormone abscisic acid(ABA) was proposed.The operating pH,absorption time,absorption temperature and concentration of anti-ABA antibody were investigated to optimize the analytical performance.The calibration curve for the determination of ABA was obtained from this impedance immunosensor under optimal conditions.The results showed that the detection limit at about 1 ng/mL in the range of 10-5000 ng/mL...
Li, QianWang, Ruo ZhongHuang, Zhi GangLi, He SongXiao, Lang Tao
An efficient method for the simultaneous extraction and quantification of both jasmonic acid(JA)and methyl jasmonate(MeJA) from a single plant sample was developed.Plant tissues were firstly extracted by using 100%cold methanol,then the Sep-pak C18 solid-phase extraction(SPE)cartridges were adopted for the purification of sample extract,and finally JA and MeJA were determined by the liquid chromatography tandem mass spectrometry(LC-MS-MS)system.It was found that the accuracy was improved by using the extra standard for the estimation and correction of JA and MeJA losses in the extraction and purification process.The detection limits for JA and MeJA were 0.03 and 0.075 ng mL-1,respectively,and the average recovery rate of JA and MeJA was 92.48%and 94.30%.The method was found to be reproducible and selective,yielding well isolated and easily detectable peaks for both JA and MeJA and simplifying the time-consuming extraction and purification.High-performance liquid chromatography(HPLC)system was employed as the control detection method for the LC-MS-MS system.The two systems were compared in their specificity and accuracy.
LIU Xia YANG YanLi LIN WanHuang TONG JianHua HUANG ZhiGang XIAO LangTao
