Herein we purpose to utilize upconverting phosphors to detect explosives. To detect TNT, antibodies specific
to TNT are conjugated to the surface. The role of the antibodies is two fold; to bind a quencher and to accept
TNT. The quencher is a bifunctional molecule, with one end containing a TNT analog and the other end being
a dark fluorescent quenching dye. The dye is chosen so that the luminescence from the phosphor will be
absorbed preventing it from emitting, reducing luminescence from the phosphor. However, in the presence of
TNT the quencher that is bound with DNT will be displaced. With the quencher displaced the phosphor will be
able to emit light indicating TNT is present in the select area.
Rare earth doped upconverting nanoparticles have been synthesized via laser vaporization controlled
condensation (LVCC) and their photoluminescence properties were characterized using 980 nm laser diode excitation.
This procedure is highly tunable, specifically by increasing the Yb<sup>3+</sup> to Er<sup>3+</sup> concentration the observed green emission
decreases and the observed red emission increases. We have also shown that nearly equal peaks of blue, green and red
emissions producing a virtually white upconverter could be synthesized by appropriately mixing Tm<sup>3+</sup>, Ho<sup>3+</sup>, and Er<sup>3+</sup>.
We have also investigated the upconversion efficiency in a variety of lattices including Y<sub>2</sub>O<sub>3</sub>, Gd<sub>2</sub>O<sub>3</sub> and La<sub>2</sub>O<sub>3</sub>. TEM
confirmed that the as-formed particles were ~ 10 nm in size and XRD indicated that the overall crystal structure was