Dual-Modal Photoelectrochemical and Visualized Detection of Copper Ions

Abstract

Copper is one of the extensively utilized heavy metals in modern industry and can be easily released into the environment due to high solubility of copper ions (Cu2+). Its percolation in water and accumulation along the food chain pose a serious threat to human health. Hence, it is of great significance to explore a novel, facile, and sensitive detection method for Cu2+. Based on the intriguing photo-to-electricity conversion process of CdS QDs, as well as desirable electrochromic property of WO3 NFs, a dual-modal photoelectrochemical (PEC) and visualized detection platform for Cu2+ is fabricated. The electrochromic WO3 NFs act as a display for the Cu2+ concentration, of which the color change could be observed directly by the naked eye, while the PEC signal provides accurate data for further analysis. In this work, a sensitive detection of Cu2+ in the range of 1 × 10–5 to 5 × 10–4 M is achieved, with a detection limit of 3.2 × 10–6 M. The dual-modal analysis gives more choices for signal readouts with enhanced quantification reliability, which is adaptive for diverse application scenarios, especially for on-site investigation. This protocol offers a prototype for quick and reliable detection of the Cu2+ concentrations, and is promising for other environmental pollutants.

Portable Visual Photoelectrochemical Biosensor Based on a MgTi2O5/CdSe Heterojunction and Reversible Electrochromic Supercapacitor for Dual-Modal Cry1Ab Protein Detection

“…Specifically, under light illumination, the photoinduced electrons generated by the photoanode with photosensitive materials are injected into the photocathode with electrochromic materials, causing the rapid reduction of electrochromic materials to produce color changes . The existence of the target affects the electron transfer rate and the reduction rate of the electrochromic material, which changes the color of the electrochromic material, realizing visual detection. , Therefore, the visual PEC biosensor offers a way to design portable and visualized signal outputs. The key elements for such a biosensor are the signal driver and display screen.…”

“…4 The existence of the target affects the electron transfer rate and the reduction rate of the electrochromic material, which changes the color of the electrochromic material, realizing visual detection. 5,6 Therefore, the visual PEC biosensor offers a way to design portable and visualized signal outputs. The key elements for such a biosensor are the signal driver and display screen.…”