Abstract: Embodiments include a particle comprising a surface enhanced spectroscopy (SES)-active core and a SES-active reporter molecule associated with the SES-active core wherein said particle has a measurable SES spectrum when excited by incident light having a wavelength of at least 1400 nm. Alternative embodiments include methods of manufacturing said particle and methods of tagging a material with said particle. The particle may include an SES-active core which supports plasmon resonance at a wavelength of at least 1400 nm. The particle may comprise an anisotropic core. The particle may include an SES-active reporter molecule which is resonant at one or more wavelengths greater than or equal to 1400 nm.

Abstract: A SERS tag comprising a core comprising at least two aggregated particles of a SERS enhancing material wherein the contact point between the particles defines a crevice; and a reporter molecule having a length sufficiently short to fit into the crevice and a conjugated path length which is as large as possible, provided the overall reporter molecule length is maintained sufficiently short to fit into the crevice.

Abstract: A SERS tag comprising a core comprising at least two aggregated particles of a SERS enhancing material wherein the contact point between the particles defines a crevice; and a reporter molecule having a length sufficiently short to fit into the crevice and a conjugated path length which is as large as possible, provided the overall reporter molecule length is maintained sufficiently short to fit into the crevice.

Abstract: Embodiments include a particle comprising a surface enhanced spectroscopy (SES)-active core and a SES-active reporter molecule associated with the SES-active core wherein said particle has a measurable SES spectrum when excited by incident light having a wavelength of at least 1400 nm. Alternative embodiments include methods of manufacturing said particle and methods of tagging a material with said particle. The particle may include an SES-active core which supports plasmon resonance at a wavelength of at least 1400 nm. The particle may comprise an anisotropic core. The particle may include an SES-active reporter molecule which is resonant at one or more wavelengths greater than or equal to 1400 nm.

Abstract: A suspendable SERS nanotag. As used herein, a suspendable tag is one which remains suspended in a specific liquid, water for example, for a period of time. Thus, a suspendable tag does not sink to the bottom of a container of the liquid or float to the top of a container of the liquid within the selected time period. A suspendable SERS nanotag may include a metal core, for example, an Au core having a diameter of less than 90 nm. The suspendable SERS nanotag may also include a SERS active reporter molecule associated with the core and a silica containing encapsulant, encapsulating the core and reporter association.