A novel growth-based plasmonic sensor for H2O2 determination was developed from dual-shaped silver nanostructures consisting of starch-stabilized yellow silver nanospheres (AgNSs) and citrate-capped red silver nanoprisms (AgNPrs). The unique ability of H2O2 to oxidize silver nanoparticles and reduce silver ion consequently was exploited to produce a highly sensitive and selective sensor (AgNSs/NPrs). AgNPrs were enlarged through a unique mechanism of AgNSs dissolution to silver ions which are subsequently reduced to silver metal by H2O2. This highly unique process addresses the selectivity issues encountered with decomposition-based AgNSs/NPrs sensors. Citrate-capping of the AgNPrs only allows the lateral growth that resulted in a red shift and intensity enhancement of the in-plane dipole plasmon resonance (IPDPR) band. Consequently, distinct hues from yellow, orange, red, purple to blue were produced from the sensors, thus allowing simple and efficient naked-eye detection with highly selective and sensitive H2O2 measurement.
- Charles Oliver Avenido
- Kanet Wongravee
- Monpichar Srisa-Art