Sodium (E)‐3‐hydroxy‐4‐((2‐hydroxynaphthalen‐1‐yl)diazenyl)naphthalene‐1‐sulfonate (Calcon, CAL), is employed for the first time as a reversible colorimetric chemosensor to detect and measure Ce3+ and H2PO4− sequentially in the aqueous medium. The detection process has two steps. The interaction of CAL and Ce3+ in the first step with a noticeable color shift from purple to blue. Further, the reaction between CAL‐Ce3+ and H2PO4− shows a clear color return from blue back to initial purple similar to that for CAL. The UV–visible examination of this color return reveals that H2PO4− removes Ce3+ and restores CAL content. The results showed that CAL and CAL‐Ce3+ had a strong binding affinity and adequate detection limits for the Ce3+ and H2PO4−, respectively. For Ce3+, the linear range and detection limit are 1.20 × 10−6‐1.02 × 10−4 and 2.0 × 10−7molL−1, while for H2PO4−, they are 2.0 × 10−7‐8.7 × 10−6 and 3.0 × 10−8 molL−1. Finally, we measured these two ions in real samples using this methodology. Furthermore, the examination of the suggested receptor's logical behavior revealed that it can operate as a colorimetric chemosensor of the INHIBIT type, receiving chemical inputs and producing a UV–visible absorbance signal as the output. If Ce3+ and H2PO4− inputs are added in proper order, the receptor may also function as a molecular “keypad lock.”

中文翻译：

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一种简单、灵敏、选择性比色化学传感器，用于连续测定双分析物 Ce3+、H2PO4− 及其在逻辑门结构和键盘锁系统中的应用

(E)-3-羟基-4-((2-羟基萘-1-基)二氮烯基)萘-1-磺酸钠 (Calcon, CAL) 首次用作可逆比色化学传感器来检测和测量 Ce3+和H2采购订单4-依次在水介质中。检测过程有两个步骤。 CAL与Ce的相互作用3+第一步，颜色明显从紫色变为蓝色。此外，CAL-Ce之间的反应3+和H2采购订单4-显示出清晰的颜色从蓝色返回到初始紫色，类似于 CAL。对该颜色返回的紫外可见检查表明 H2采购订单4-去除 Ce3+并恢复 CAL 内容。结果表明 CAL 和 CAL-Ce3+对 Ce 有很强的结合亲和力和足够的检测限3+和H2采购订单4-， 分别。力量3+，线性范围和检测限为1.20×10−6‐1.02×10−4和2.0×10−7摩尔−1，而对于 H2采购订单4-，它们是 2.0 × 10−7‐8.7×10−6和3.0×10−8摩尔−1。最后，我们使用这种方法测量了实际样品中的这两种离子。此外，对所建议受体的逻辑行为的检查表明，它可以作为 INHIBIT 类型的比色化学传感器运行，接收化学输入并产生紫外可见吸收信号作为输出。如果Ce3+和H2采购订单4-输入以正确的顺序添加，受体还可以充当分子“键盘锁”。