Removal and direct visual monitoring of Lead(II) using amino acids functionalized polyacrylonitrile nanofibrous membranes

Materials for the removal and visual monitoring of ultra-trace levels of lead ions (Pb 2+ ) from impaired drinking water are essential and vital to reduce the enormous effect of Pb 2+ on human health. However, it remains a significant challenge to achieve both high adsorption capacity and low naked eye detection limit. Here, we present a strategy to create a Pb 2+ removal and contamination degree detecting system by combining electrospun nanofibrous membranes (NMs) with a flow-through system. This approach allows amino acids to graft on hydrolyzed-polyacrylonitrile (AA-HPAN) NMs to perform as adsorbents and colorimetric strips with tortuous porous structure and large surface area. The resultant AA-HPAN NMs exhibit the integrated properties of high adsorption capacity and excellent reversibility. Furthermore, the dynamic removal and recognition experiment were performed and a naked-eye detection limit of 0.048 μM using sodium rhodizonate as the color initiator. Considering the good removal and monitoring performance of the AA-HPAN NMs, this intriguing approach may pave the way for constructing of membranes with the versatility to sever as a preventive strategy to keep the public from Pb 2+ exposure.