A multicolor electrochemiluminescence (ECL) device was constructed based on closed bipolar electrode (BPE) for visualized sensing of Salmonella typhimurium (S. typhimurium). Since the emission color of concomitant electrochemiluminophores ([Ir(ppy)₃] and [Ru(bpy)₃]²⁺) is potentially distinguish, selective excitation of ECL could be obtained by regulating the interfacial potential at the poles of BPE. Via modulating the resistance of BPE, bidirectional color change from dark-orange to yellow to forest-green could be observed at the anode, which was ascribed to the dual-potential excitation property of the concomitant electrochemiluminophores. The presence of S. typhimurium on the cathode of BPE increases the resistance in the circuit, generating ECL reporting color at the other pole switched. In accordance with this multicolor BPE-ECL sensor, a low detection limit of 10 CFU mL⁻¹ of S. typhimurium could be identified in 25 mL (g) sample with naked eyes. In this work, physical isolation of the cathode and anode of closed BPE not only avoids target and electrochemiluminophores mutual interference, but also the surface of the BPE need nothing modified, just added immunomagnetic beads (IMBs)-S. typhimurium compound to the cathode. Moreover, without complex pre-enrichment bacterial, the whole experiment time also can be greatly shortened with only 0.5 h. On the other hand, the electrochemical signal is converted into a more intuitive optical readout for visualized sensing of S. typhimurium in food. The multicolor ECL device is merging the sensitivity of electrochemistry with the intuitive of an optical readout, which may apply in the site of rapid detection of food safety.

基于封闭双极电极（BPE）构建了一种多色电化学发光（ECL）装置，用于鼠伤寒沙门氏菌（S. typhimurium）的可视化传感。由于伴随的电化学发光团（[Ir(ppy) ₃ ] 和[Ru(bpy) ₃ ] ²⁺）的发射颜色可能是有区别的，因此可以通过调节 BPE 两极的界面电位来获得 ECL 的选择性激发。通过调节 BPE 的电阻，可以在阳极观察到从深橙色到黄色到森林绿色的双向颜色变化，这归因于伴随的电化学发光团的双电位激发特性。S的存在BPE 阴极上的鼠伤寒会增加电路中的电阻，在切换的另一极产生 ECL 报告颜色。根据该多色BPE-ECL传感器，10 CFU mL的检出限低^-1的S.鼠伤寒可以25毫升（g），用肉眼样品中被识别。在这项工作中，封闭BPE阴极和阳极的物理隔离不仅避免了靶标和电化学发光体的相互干扰，而且BPE的表面不需要任何修饰，只需添加免疫磁珠（IMBs）-S 。鼠伤寒化合物到阴极。此外，无需复杂的预富集菌，整个实验时间也可以大大缩短，仅需0.5 h。在另一方面，电化学信号被转换成用于感测显现更直观的光学读出S.在食品鼠伤寒沙门氏菌。多色ECL装置将电化学的灵敏度与光学读数的直观性相结合，可应用于食品安全的快速检测现场。