基于金纳米粒子的比色传感.ppt

Colorimetric Biosensing Using AuNPs Colorimetric Biosensing Using Smart materials low cost, simplicity, and practicality. does not require expensive or sophisticated instru-mentation . applied to ?eld of analysis and point-of-care diagnosis transforming the detection events into color changes. Gold Nanoparticles (AuNPs) Small AuNPs (e.g., 15 nm in diameter) appear red in color because the nanoparticles have an optical absorption around 520 nm due to surface plasmon resonance.When small AuNPs aggregates will make their surface plasmons combine and result in the color change from red to purple. AuNPs Aggregation Interparticle crosslinking Non-crosslinking Aggregation Crosslinking Aggregation Non-crosslinking Aggregation  In preparation of AuNPs, the surface-tethered capping ligands or species are often used to control AuNPs growth and to stabilize AuNPs against van der Waals attraction-induced aggregation. With respect to electrostatic stabilization, the surface charges, together with the counter ions in the medium, form a repulsive electric double layer that stabilizes colloids against van der Waals attractive forces. * * Contents Colorimetric Biosensing UsingSmart Materials 1 Application 2 Conclusions 3 Common Smart materials Smart materials graphene oxide conjugated polymers carbon nanotubes magnetic NPs AuNPs cerium oxide NPs