Amanda J. Haes

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A nanoscale optical biosensor based on localized surface plasmon resonance (LSPR) spectroscopy has been developed to monitor the interaction between the antigen, amyloid-beta derived diffusible ligands (ADDLs), and specific anti-ADDL antibodies. Using the sandwich assay format, this nanosensor provides quantitative binding information for both antigen and(More)
Triangular silver nanoparticles ( approximately 100 nm wide and 50 nm high) have remarkable optical properties. In particular, the peak extinction wavelength, lambda(max) of their localized surface plasmon resonance (LSPR) spectrum is unexpectedly sensitive to nanoparticle size, shape, and local ( approximately 10-30 nm) external dielectric environment.(More)
The intense colors of noble metal nanoparticles have inspired artists and fascinated scientists for hundreds of years. In this review, we describe refractive index sensing platforms based on the tunability of the localized surface plasmon resonance (LSPR) of arrays of silver nanoparticles and of single nanoparticles. Specifically, the color associated with(More)
The Ag nanoparticle based localized surface plasmon resonance (LSPR) nanosensor yields ultrasensitive biodetection with extremely simple, small, light, robust, and low-cost instrumentation. Using LSPR spectroscopy, the model system, biotinylated surface-confined Ag nanotriangles, was used to detect less than one picomolar up to micromolar concentrations of(More)
The distance and orientation dependence of the heterogeneous electron-transfer reaction between ferrocytochrome c (Fe2+Cc) and a silver film over nanosphere (AgFON) electrode is examined in detail using electrochemical surface-enhanced resonance Raman spectroscopy (SERRS) as a molecularly specific and structurally sensitive probe. The distance between the(More)
Covalently functionalized gold nanoparticles influence capillary electrophoresis separations of neurotransmitters in a concentration- and surface-chemistry-dependent manner. Gold nanoparticles with either primarily covalently functionalized carboxylic acid (Au@COOH) or amine (Au@NH(2)) surface groups are characterized using extinction spectroscopy,(More)
Early work with size-tunable periodic particle arrays (PPAs) fabricated by nanosphere lithography (NSL) demonstrated that the localized surface plasmon resonance (LSPR) could be tuned throughout the visible region of the spectrum. The LSPR is sensitive to changes in nanoparticle aspect ratio and local dielectric environment. This property has recently been(More)
The radius of curvature of gold (Au) nanostar tips but not the overall particle dimensions can be used for understanding the large and quantitative surface-enhanced Raman scattering (SERS) signal of the uranyl (UO2)(2+) moiety. The engineered roughness of the Au nanostar architecture and the distance between the gold surface and uranyl cations are promoted(More)
Silica coated gold nanospheres are purified using traditional centrifugation steps and/or anion exchange chromatography and their resulting surface-enhanced Raman activities compared. Partially silica-coated gold nanostructures are retained on the column while fully coated nanostructures elute. As a result, SERS activity becomes less erratic and follows(More)
In this review, the most recent progress in the development of noble metal nano-optical sensors based on localized surface plasmon resonance (LSPR) spectroscopy is summarized. The sensing principle relies on the LSPR spectral shifts caused by the surrounding dielectric environmental change in a binding event. Nanosphere lithography, an inexpensive and(More)