英语翻译For studying the nature of the interaction between senso

英语翻译
For studying the nature of the interaction between sensor
QB and Zn2+/Cd2+,1H NMR titrations were also carried out
(Figure 5 and Table S2,Supporting Information).Upon
interaction with Zn2+ and Cd2+,the protons of the methoxy
CH3 experienced significant upfield shifts (ΔδZn ) 0.97; ΔδCd
) 0.41 ppm),indicating that the oxygen atom of the methoxy
group strongly bonded with Zn2+/Cd2+.The protons at ortho
position of pyridines downfield shifted from 8.49 to 8.66
(Zn2+) and to 8.80 (Cd2+),respectively,by N-metal coordination
effect.Meanwhile,similar upfield shifts were also
observed for the proton at the 3-position of quinoline,
suggesting the direct interaction between quinoline platform
and metal ions.When 4 equiv of Cd2+ was further introduced
into the ZnQB solution,compare Figure 5d with 5b,
chemical shifts of all protons changed significantly and are
almost identical with these of the sole CdQB (Figure 5c).
The finding indicates that QB has higher affinity for Cd2+
than for Zn2+,which consequently incurs the ion displacement
process.
In conclusion,we have developed a novel fluorescent
sensor,QB.It shows a ratiometric response to Zn2+ based
on both CHEF and ICT mechanisms but a CHEF response
to Cd2+.Moreover,we show that the central ion of ZnQB
can be displaced by Cd2+,resulting in another ratiometric
sensing signal output.Thus,QB can be a dual mode Cd2+-
selective sensor via the CHEF mechanism and ratiometric
displacement approach.

为了研究传感器QB和Zn2＋/Cd2＋之间的互作用,还进行了氢核磁共振滴定（支持信息图5和表S2）.在与Zn2＋和Cd2＋互作用时,甲氧基CH3的质子经历明显的高场（upfield）偏移（ΔδZn=0.97.ΔδCd=0.41ppm）,表明了甲氧基基团的氧原子与Zn2＋/Cd2＋强烈结合.在吡啶低场邻位的质子因为N-金属协合效应而分别从8.49偏移到8.66（Zn2＋）和8.80（Cd2＋）.
与此同时,类似的高场偏移在喹啉的3位置处的质子情况下也观察到了,揭示了喹啉平台和金属离子之间的直接互作用.当进一步将4个当量的Cd2＋引入ZnQB溶液时,比较图1d与图5b,所有质子的化学位移都明显改变而几乎与单独CdQB的位移相同（图5c）.这一发现表明,QB对Cd2＋比对Zn2＋具有较高的亲和力,这招致了离子置换过程.
总的来说,我们已经开发了一种新的荧光传感器QB.它基于CHEF和ICT机理而对Zn2+显示出比率响应,而对Cd2＋则显示CHEF响应.而且,我们证明了,ZnQB的中心离子可以被Cd2＋置换,得到另一种比率传感信号输出.因此,QB通过CHEF机理和比率置换途径可以成为一种双模Cd2＋选择性传感器.