Preparation of Polymer@AuNPs with Droplets Approach for Sensing Serum Copper Ions

A microfluidic droplet synthesis approach for the preparation of poly N-isopropylacrylamide protected gold nanoparticles (PNIPAm@AuNPs) was presented here. Well-dispersed PNIPAm@AuNPs could be generated within 8 min. On the basis of the aggregation-induced UV–vis adsorption intensity increasing mechanism, the PNIPAm@AuNPs-based colorimetric probe displayed high sensitivity and good selectivity for sensing copper ions. A linear calibration of relative UV–vis adsorption intensity increasing versus copper ions concentration was obtained within 5.0–750.0 μM, and the limit of detection was 2.5 μM. Furthermore, after copper ions were injected in rat, a metabolic assay was developed with the proposed probe. The results indicated that the droplet microfluidic synthesis system could provide a new way for preparation of polymer@AuNPs with good polydispersity index and showed great potential of polymer@AuNPs-based sensing probe for application in biological and clinical analysis.