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.