Hierarchical porous carbon confined core (Cu)-shell (Ag) bimetals for highly sensitive simultaneous detection of isoproturon and norfloxacin

A novel nanocomposite consisting of core (Cu)-shell (Ag) nanoparticles encapsulated in carbon nanotubes (CTs) grown on a MOF-derived carbon framework was synthesized by in-situ pyrolyzing method. After further modification with multi-walled carbon nanotubes (MWCNTs), a hierarchical porous carbon network confined core (Cu)-shell (Ag) bimetal (Cu@Ag@CTs/MWCNTs) with excellent catalytic properties to isoproturon (ISO) and norfloxacin (NOR) was obtained. The electrochemical sensor based on the Cu@Ag@CTs/MWCNTs can simultaneously detect the ISO and NOR with excellent sensitivity, good selectivity and perfect stability as well as a separation of peak potential of 270 mV. The calibration curves for ISO and NOR achieved by the proposed sensor range from 80 nM to 18 μM and 7.0 nM to 1.7 μM with detection limits of 26 nM and 2.0 nM, respectively. Moreover, the sensor shows good recoveries in simultaneous detection of ISO and NOR in real sample analysis, highlighting its high feasibility in practical application.