Tailored polyethyleneimine-based fluorescent nanoparticles for functionalized applications in detection and adsorption of cobalt (II)

Facile fabrication of water-soluble fluorescent polymer nanoprobes for trace detection of cobalt ion (Co2+) is still a demand in environmental and biological fields. The sphere-like nanoscale PEI-MA was successfully synthesized by hyperbranched polyethyleneimine (hPEI) and mercaptosuccinic acid (MA) via hydrothermal treatment. The synthesized PEI-MA had good selectivity and sensitivity, with a wide detection range (0–200 μM) and a low detection limit (0.27 μM) to Co2+ in aqueous solution. The low bio-toxicity and cell permeability were demonstrated by HeLa cell imaging, indicating the PEI-MA with certain potential could be utilized in the field of biosensing domain. Meanwhile, the PEI-MA was employed in adjustable fluorescent dyes and fabrication of portable solid sensors. Among these PEI-DA-doped sensors, test strips and nanofibrous fluorescent films with remarkable fluorescent performance could be used as effective monitoring devices for the detection of Co2+. Moreover, the dual-functional fluorescent hydrogels owned functions of detection and adsorption for Co2+ in water system, providing ingenious reference for the interdisciplinary research between fluorescent sensing and adsorption of Co2+.