(166k) Characterization and Application of Laboratory Grade Nanoscale Egyptian Blue

Calcium copper silicate (CaCuSi₄O₁₀), known as Egyptian Blue (EB), is a pigment that exhibits a strong near-IR (910 nm) fluorescent emission when exposed to a strong visible light source.This property makes it a novel candidate for use as a basis for nanomaterial-based sensors in surface water, as its IR signal is very strong in comparison with current commonly used IR reporters. Also, IR signals penetrate biological samples better, and are scattered less than visible range signals. A sample of EB was synthesized by a solid-state reaction outlined by Johnson-McDaniel and Salguero. In order to reduce the particle size to nanoscale, exfoliated EB powder and exfoliated EB powder covered with cetyltrimethylammonium bromide were prepared. The powders were adhered to glass discs in conjunction with (3‑aminopropyl)triethoxysilane to develop lens coatings that fluoresce in the near-IR spectrum. Dynamic light scattering was performed to obtain information on particle sizes. Phase shifting interferometry was performed to characterize the surface coatings of the glass discs and to obtain the size distribution of the adhered nanoparticles. The performance of the lens coatings was characterized by photoluminescence spectroscopy.