A novel solid-state electrochemiluminescence sensor based on Ru(bpy)₃^{2 +}immobilization on TiO₂nanotube arrays and its application for detection of amines in water

Abstract

Many amines are proven or suspected to be carcinogenic and have been implicated in inducing cancer of the bladder. Therefore, the monitoring of their levels in environmental samples is important for the protection of health and the environment. Herein, a novel method for effective immobilization of Ru(bpy)(3)(2+) on the electrode surface of TiO(2) nanotube arrays (TNs) is developed for the first time. The method involves Ru(bpy)(3)(2+) spontaneously adsorbed on the surface of negatively charged TiO(2) nanotubes due to electrostatic interaction to produce a Ru(bpy)(3)(2+) /TNs/Ti (Ru-TNs-Ti) solid-state electrochemiluminescence (ECL) sensor. The prepared solid-state sensor was used to detect the changes of concentrations of pollutant tripropylamine (TPA) in water. The sensor exhibits excellent ECL behavior, very good stability and high sensitivity. This study may provide new insight into the design and preparation of an advanced solid-state ECL sensor for monitoring of amines in water.

Enhanced Electrochemiluminescence Performance of Ru(bpy)32+/CuO/TiO2 Nanotube Array Sensor for Detection of Amines

“…Figure 5 shows the ECL‐potential curves at Ru‐Cu‐TN and Ru‐TN electrodes. The redox waves corresponding to the Ru 3+ /Ru 2+ couple were not clearly observed at the Ru‐Cu‐TN (shown in the inset of Figure 5b) and Ru‐TN electrodes, similar to the previous report 19, presumably due to the overlap of the current. It is presumably caused by the rapid increase of anodic current above ca.…”

“…In contrast to pure TNs and Cu‐TNs, both Ru‐TNs and Ru‐Cu‐TNs exhibit two new absorption peaks at ca. 285 and 450 nm, which are consistent with electronic π–π* transition and metal‐to‐ligand charge‐transfer ( MLCT) transition (dπ→π*) of Ru(bpy) 3 2+ 19,43, respectively. The above results suggest that Ru(bpy) 3 2+ has been successfully immobilized on TNs and Cu‐TNs.…”

“…The process of immobilization of Ru(bpy) 3 2+ on TNs or Cu‐TNs was as follows 19. The crystallized TNs or Cu‐TNs were firstly immersed in an ethanol‐water solution ( V ethanol : V water =1 : 1) containing 0.05 mM Ru(bpy) 3 Cl 2 (Aldrich) and 0.05 M phosphate buffer (pH 7.4) for 20 h and dried at 70 °C.…”

“…Compared to the solution‐phase Ru(bpy) 3 2+ ‐ECL system, solid‐state Ru(bpy) 3 2+ ‐ECL sensors can exhibit some merits such as an enhanced ECL signal, low consumption of expensive ECL reagent and reusable sensing applications based on Ru(bpy) 3 2+ recycled at the electrode surface 10–13. A number of approaches have been developed to fabricate solid‐state Ru(bpy) 3 2+ ‐ECL sensors, including Langmuir‐Blodgett 14, 15, sol‐gel 16, layer by layer self‐assembly 17, 18 and electrostatic interaction techniques 19. In general, to fabricate a solid‐state ECL sensor, a substrate electrode is indispensable on which Ru(bpy) 3 2+ is immobilized.…”

“…Moreover, the pore sizes, lengths and wall thicknesses of TNs can be precisely tuned by tailoring electrochemical conditions. Recently, we have developed a solid‐state ECL sensor based on Ru(bpy) 3 2+ immobilization on TNs for detection of amines 19. The TNs serve not only as a substrate electrode, but also as a support for immobilising Ru(bpy) 3 2+ .…”