Reduced graphene oxide-cyclodextrin-chitosan electrochemical sensor: Effective and simultaneous determination of o- and p-nitrophenols

Dual‐opposite multi‐walled carbon nanotube modified carbon fiber microelectrode for microfluidic chip‐capillary electrophoresis determination of methyl parathion metabolites in human urine

“…To avoid interference from the reduction of dissolved oxygen, all solutions were deaerated by bubbling N 2 for 10 min before conducting electrochemical tests. Three NP metabolites all showed a reduction plateau when the potential is scanned to a voltage more negative than −0.8 V, which was attributed to a four‐electron transfer reduction of the nitro group to produce the hydroxylamine species . For 4‐NP, there was also an oxidation peak appearing around +1.0 V, which could be assigned as the oxidation of the phenol group to produce radical species .…”

“…pH plays a key role in the determination of metabolites because it not only affects the EOF and the degree of ionization of the metabolites, but also current response of the three metabolites. Since analysis time is very long at pH lower than 6 and the electrochemical current response for nitrophenol is rather low at pH greater than 9.0 , we investigate the influence of pH ranging from 6.5 to 8.5. Results show that all three analytes can be baseline separated in this pH range and the analysis time for one CE run is shorter at a higher pH due to the higher EOF.…”

β-Cyclodextrin as an Ionophore for Membrane Electrode

“…They used a voltammetric sensor on mesoporous carbon @polydopamine and β-CD. It showed a response for chloramphenicol in the range of 5 Â 10 À7 À 5 Â 10 À5 M. Li et al [6] determined o-and p-nitrophenol by using reduced graphene oxide-CD-Chitosan electrochemical sensor. It was based on the host-guest recognition sites on CD and abundant functional groups of Chitosan.…”

Resolution of a Mononitrophenol Isomers Mixture by Differential Alternative Pulses Voltammetry

“…The currently applied analytical methods for nitrophenols quantification are spectrophotometric , chromatographic , and electrochemical , as well as flow‐injection analysis , and capillary electrophoresis . Among them the electrochemical techniques and especially the voltammetry attract the attention, due to their cost efficiency, rapid response, simple operation, and on‐site application ability.…”

“…The main difficulty associated with the voltammetric simultaneous determination of the nitrophenol isomers is the insufficient resolution of the nitrophenols overlapped peaks and hence, the low quantification precision. This problem was overcome by signal differentiation or by the application of chemically modified electrodes with improved performances, or both . However, the differentiation presents important disadvantages in increased noise level or insufficient number of sampling points .…”