A photoelectrochemical sensor composed of a heterojunction between titanium dioxide and gold nanoparticles was fabricated and used for the determination of ciprofloxacin, a widely used, but environmentally toxic third‐generation antibiotic. This material has been extensively characterized from the morphological, electrochemical and photoelectrochemical points of view, comparing it with the respective counterparts. It has been demonstrated that only the presence of the heterojunction allows the detection of ciprofloxacin, thanks to the properties of gold nanoparticles combined with those of titanium dioxide. These increased performances have allowed the detection of the analyte even with low power sources and wavelengths in the visible region, obtaining good detection limits and excellent resistance to possible interferents. Thanks to this, the future implementation of these sensors in integrated circuits for online and onsite analysis is foreseen.

The Front Cover shows the photoelectrochemical sensor prepared by covering gold nanoparticles (AuNPs) with a thin layer of TiO2. The obtained hybrid material, which exploits synergistically the properties of its components, was used to monitor ciprofloxacin, exhibiting a response only once irradiated. Good performances were obtained using a low‐power LED. Such discovery may pave the way for future in situ applications in environmental monitoring. More information can be found in the Research Article by D. Fumagalli et al.

What is the most significant result of this study?Although electroanalytical techniques are well suited for in situ analysis thanks to portable, compact, and inexpensive instrumentation, the use of photocurrent measures is generally limited by the need to irradiate the sample with high-power light sources, often in the UV region of the spectrum. The published work highlights how, for the first time, it was possible to obtain good analytical performances also through the use of low-power LEDs. This discovery could pave the way for many applications, for example in the environmental field for the monitoring of polluting species.