Nano Lett. 11, 3431–3434 (2011)

Credit: © 2011 ACS

Cytokines are molecules secreted by cells for signalling and are essential to intercellular communication. Sheng Wang and colleagues from the University of California and Lawrence Berkeley National Laboratory in the USA have now developed a technique for imaging extracellular signalling at subcellular resolution. First, they used nanoimprint lithography to fabricate an array of plasmonic resonators, each 100 nm in diameter and comprising two 20 nm gold layers sandwiching a 5 nm silicon dioxide film, which together provided an optical resonance at ∼670 nm. They then cultured the surface of the array with Jurkat T cells — a type of cell used to study T-cell leukaemia and T-cell signalling. They mapped interleukin-2 (IL-2, the cytokine signalling molecule) secreted by the cells using plasmonically enhanced fluorescence.