We reported here the unique ability of a Rhodamine 6G-based probe (3) to detect discriminately several targets, including H+,HO−, Cu2+, Hg2+, Fe3+, Co2+, Cd2+, Zn2+, Sn2+, Ni2+, Al3+, Pb2+, Ce3+and Ag+
, by unambiguously colorimetric and fluorimetric outcomes. In aqueous solutions, the presence of proton induced the ring-opening of rhodamine moiety but the presence ofhydroxide induced the conversion of 2-hydroxyphenyl hydrazone moiety from the non-fluorescent benzenoid form into the fluorescent quinoid form. The probe could to distinguish between different cations in DMF and to work like an artificial tongue at molecular level. Several logic gates including OR, INHIBIT and TRANSFER, were performed by the probe. Moreover, the probe is able to execute three INHIBIT logic gates by two inputs, which was exploited to execute a digital molecular comparator.