Plasmonic spectra of individual subwavelength particles under the infrared microscope: cells and airborne dust

Dust Library of Plasmonically Enhanced Infrared Spectra of Individual Respirable Particles

“…The experimental setup for recording single particle spectra of wavelength scale particles has been described in detail elsewhere. [10][11][12]15,34 The particles are trapped in a metal film with an array of microholes, plasmonic Ni mesh, 10,12,15 having a 12.6 mm square lattice parameter, 5 mm square hole size, and $2 mm thickness as available from Precision Eforming (Cortland, NY; http://www.preci sioneforming.com). Briefly, dust sample powder is placed over the mesh and air is sucked through it using a pump that traps globular particles having widths that are slightly smaller than the mesh holes.…”

“…Given the known symptoms of inhaling high levels of particulate matter and the risks associated with long-term exposure to elevated levels, there is a need to chemically evaluate such particles. 10 Our previous single particle work [10][11][12][13][14][15] includes the study of a spectral library of 63 individual dust particles extracted from our laboratory air 12 demonstrating chemical variability including minerals, sulfates, nitrates, and organics, as well as a model for analysis of volume fractions. 10 In this work, the study is extended to samples obtained from a home air filter and the 11 September 2001 World Trade Center (WTC) event.…”

“…31,32 The Coe group has recorded IR spectra of individual subwavelength particles including live yeast cells, 11 latex microspheres, 32,33 and calibrant materials 10 (quartz, gypsum, carbonates, different types of clay, humic acid/salt). This work applies a common analysis 10 to three dust samples, including dust from lab air, 10 a home air filter, 15 and the September 11, 2001 World Trade Center event by using plasmonic Ni mesh and an imaging FTIR microscope.…”