Templated one-step synthesis of compositionally encoded nanowire tags

Multimetal nanowire tags, with distinct encoding patterns, have been prepared using a one-step templated electrodeposition from solutions containing different concentrations of various metal ions. Such synthesis of compositionally encoded nanowire tags is substantially faster and simpler than the preparation of striped nanowires based on sequential plating steps from different metal solutions and leads to high identification accuracy. The alloy nanowire preparation route leads to a high coding capacity with a large number of distinguishable voltammetric signatures, reflecting the predetermined composition of the metal mixture plating solution (and hence the nanowire composition). Factors influencing the identification accuracy are evaluated using three-metal (In, Pb, Bi) alloy nanowires, and the relative advantages and disadvantages of the new route are discussed.