Pyrene derivative-functionalized mesoporous silica-Cu2+ hybrid ensemble for fluorescence "turn-on" detection of H2S and logic gate application in aqueous media.

ABSTRACT

The ensemble system PyH-SBA-15-Cu2+ was obtained via coordination interaction of pyrene derivative-functionalized mesoporous SBA-15 and Cu2+, and applied for the selective and sensitive detection of H2S over pH 6.0-12.0 in aqueous media. The sensing strategy was designed on the basis of the H2S-induced dissolution of Cu2+ from PyH-SBA-15-Cu2+. Cu2+ has good binding affinity to N atoms in PyH-SBA-15; therefore, the organic-inorganic hybrid ensemble PyH-SBA-15-Cu2+ was formed, which is nonfluorescent in aqueous solution because of the Cu2+-promoted emission quenching of PyH-SBA-15. The addition of H2S induces the dissolution of PyH-SBA-15-Cu2+ by the formation of stable CuS, thereby producing fluorescence revival of PyH-SBA-15. The correlative "turn-on" fluorescence signals of this ensemble system are linearly proportional to [H2S] in the concentration region of 0-1.0 × 10-4 M, showing a low detection limit of 3.7 × 10-7 M. Other common anions do not induce distinct fluorescence changes. When using the fluorescence intensity signal changes of PyH-SBA-15 as outputs and Cu2+ and S2- as inputs, PyH-SBA-15 can act as an XNOR logic gate.