A Multiwall Carbon Nanotube-chitosan Modified Electrode for Selective Detection of Dopamine in the Presence of Ascorbic Acid

A novel multiwall carbon nanotube-chitosan modified electrode has been prepared.The modified electrode resolves the overlapping voltammetric response of dopamine and ascorbicacid into two well-defined peak by 212 mV. The mechanism of discrimination of dopamine fromascorbic acid is discussed. Dopamine can be determined selectively with the carbonnanotube-chitosan modified electrode. The electrode shows good sensitivity, selectivity andstability.

Electrochemical Chiral Recognizing Tryptophan Enantiomers Based on Chiral Metal-Organic Framework D-MOF

In this work,an electrochemical chiral sensor of a nanowire-like chiral metal-organic framework/multiwalled carbon nanotube-chitosan/glassy carbon electrode(D-MOF/MWCNTs-CS/GCE)was proposed for the enantiorecognition of L/D-tryptophan(L/D-Trp).The asymmetrical spatial structure of D-MOF provides the feasibility for the enantiorecognition of Trp enantiomers.Moreover,differential pulse voltammetry(DPV)was carried out to be the detection method and the DPV peak potential difference(ΔEp)between L-Trp and D-Trp was referred as the index of the enantiorecognition performance.Several parameters,such as mass ratios and drop-coated volume of MWCNTs-CS,drop-coated volume and concentration of D-MOF,pH and detection temperature of D-MOF/MWCNTs-CS/GCE were optimized for the largestΔEp value.And the molecular dynamics(MD)simulation was used to elucidate the enantiorecognition mechanism.Furthermore,the proportions of D-Trp(D-Trp%)in Trp mixtures were detected in a good linear relationship with the DPV peak potentials(Ep),and the proposed electrochemical chiral sensor exhibited good reproducibility,stability and enantiorecognition ability.Additionally,the proposed electrochemical chiral sensor(D-MOF/MWCNTs-CS/GCE)has a good application prospect in the fields of biomedicine,clinical diagnosis,chemical production,pharmaceuticals safety and so on.