Sequence-specific detection of H5N1 and H1N1 targets. (a) When challenged with the target H5N1 (concentration = 400 nM), sensor S1 (immobilized with H5N1 probe) responds as expected with a 38% change in signal. (b) The H5N1 target does not, however, significantly affect the signal from sensor S2 (immobilized with the H1N1 probe). After regeneration of the sensors with DI water, the device is challenged with the H1N1 target (concentration = 400 nM). (c) S1 demonstrates minimal response to the target (3%), whereas d) S2 responds with a 46% change in signaling current.