科研之友
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摘要
A nanoscale coordination-polymer (CP) architecture with a pi-conjugated backbone (Zn-ata) was synthesized in this work. In aqueous media, this material exhibited a specific fluorescence response to nitroaromatics (detection limits of 0.2-1.3 ppm) but not to nitroaliphatics, despite their similar electron affinities. Interestingly, the order of sensitivities of Zn-ata to different nitroaromatics was completely distinct from thermodynamic expectations. Through a Stern-Volmer analysis of time-resolved and steady-state : emission data, as well as measurements of the adsorption amounts, we confirmed that the sensing process occurs through a static quenching pathway. In this mechanism, the preassociation process, instead of the subsequent electron transfer, determines the quenching efficiency. The selective adsorption of nitroaromatics on Zn-ata gives Zn-ata the ability to discriminate between nitroaromatics and nitroaliphatics and enhances its response sensitivity. To the best of our knowledge, this work is the first to demonstrate the dominant role of static quenching in a CP-based sensing system.
- 出版日期2015-12-24
- 单位南开大学
