Abstract: A method for infrared chemical imaging through nondegenerate two-photon absorption includes a step of providing pulsed or continuous wave radiation having pumping photons at near-infrared wavelength and providing pulsed or continuous wave radiation that having mid-infrared photons at a mid-infrared wavelength with peak intensities less than 50 W/cm2. The mid-infrared photons are directed onto a target sample. The method also includes a step of spatially and temporally overlapping the mid-infrared photons with the pumping photons. The mid-infrared photons and the pumping photons are directed onto a camera having an array or matrix of imaging devices. Characteristically, the sum of photon energy for each temporally and spatially overlapping mid-infrared photons and pumping photons is greater than or equal to the bandgap energy.

Abstract: A method for detecting and quantifying an amount of ammonia in a sample by surface-enhanced Raman spectroscopy includes a step of position a liquid or gaseous sample proximate to a detection substrate. Incident light is focused onto the detection substrate while it is positioned proximate to the sample, the incident light having an excitation wavelength from about 500 nm to 800 nm. Raman activity from ammonia proximate to the detection substrate is then detected.

Abstract: A method for infrared chemical imaging through nondegenerate two-photon absorption includes a step of providing pulsed or continuous wave radiation having pumping photons at near-infrared wavelength and providing pulsed or continuous wave radiation that having mid-infrared photons at a mid-infrared wavelength with peak intensities less than 50 W/cm2. The mid-infrared photons are directed onto a target sample. The method also includes a step of spatially and temporally overlapping the mid-infrared photons with the pumping photons. The mid-infrared photons and the pumping photons are directed onto a camera having an array or matrix of imaging devices. Characteristically, the sum of photon energy for each temporally and spatially overlapping mid-infrared photons and pumping photons is greater than or equal to the bandgap energy.

Abstract: A method for separating metal ions from a liquid includes a step of providing a solution having metal-containing ions and associated negative counter ions in a liquid. The metal-containing ions are contacted with a dendrimer to form solid particles of metal-containing ion-dendrimer complexes. The solid particles of metal-containing ion-dendrimer complexes are separated from the solution.