Preparation of Fe(3)O(4)-Embedded Poly(styrene)/Poly(thiophene) Core/Shell Nanoparticles and Their Hydrogel Patterns for Sensor Applications

This research describes the preparation and sensor applications of multifunctional monodisperse, Fe(3)O(4) nanoparticles-embedded poly(styrene)/poly(thiophene) (Fe(3)O(4)-PSt/PTh), core/shell nanoparticles. Monodisperse Fe(3)O(4)-PSt/PTh nanoparticles were prepared by free-radical combination (mini-emulsion/emulsion) polymerization for Fe(3)O(4)-PSt core and oxidative seeded emulsion polymerization for PTh shell in the presence of FeCl(3)/H(2)O(2) as a redox catalyst, respectively. For applicability of Fe(3)O(4)-PSt/PTh as sensors, Fe(3)O(4)-PSt/PTh-immobilized poly(ethylene glycol) (PEG)-based hydrogels were fabricated by photolithography. The hydrogel patterns showed a good sensing performance under different H(2)O(2) concentrations. They also showed a quenching sensitivity of 1 μg/mL for the Pd(2+) metal ion within 1 min. The hydrogel micropatterns not only provide a fast water uptake property but also suggest the feasibility of both H(2)O(2) and Pd(2+) detection.