Multistage pore structure legume-like UiO-66-NH2@carbon nanofiber aerogel modified electrode as an electrochemical sensor for high sensitivity detection of HMIs

Electrode material is the core component of electrochemical sensor, which has a decisive influence on the detection performance of heavy metal ions. A novel electrochemical sensor based on amino modified metal-organic frameworks loaded three-dimensional carbon nanofiber aerogel composite material was proposed. The UiO-66-NH2 was embedded into nanofibers through one-step electrospinning technology to forming a legume-like structure, ensuring the number of active sites N coordination with HMIs, which improved enrichment capacity of the sensor. 3D carbon nanofiber aerogel with multistage pore structure was developed by one-dimensional nanofibers as unit modules, which increases conductive path and HMIs transport channel. Accordingly, the UiO-66-NH2 @carbon nanofiber aerogel modified electrode (N-U@CFA/GCE) as an electrochemical sensor exhibited an ultra-high sensitivity and the low limit of detection for the simultaneous detection of Cd2+ (0.52 nM) and Pb2+ (0.46 nM) using the differential pulse anode stripping voltammetry and was feasible and accurate for the detection of actual environmental water. The novel sensor platform has high sensitivity, stability and anti-interference, which showing great potential on HMIs monitoring. [Display omitted] •The UiO-66-NH2 was embedded into carbon nanofibers affording to a legume-like structure.•The multistage pore structure carbon aerogel had abundant enrichment sites and network conductive paths.•The novel sensor exhibited an ultra-high sensitivity and the low LOD for detection of Cd2+ and Pb2+.