Two-dimensional (2D) bismuth(III) sulfide (Bi₂S₃) nanosheets as non-toxic graphene-like nanomaterials were successfully fabricated by a facile liquid phase exfoliation (LPE) method. A robust photodetector employing a Bi₂S₃ nanosheet film has been fabricated for the first time via a facile fabrication process on an ITO-coated glass. UV-Vis and Raman spectroscopy techniques were carried out and they confirmed the inherent optical and physical properties of Bi₂S₃ nanosheets. Photoelectrochemical (PEC) measurements demonstrate that a significantly higher photocurrent density (42 μA cm⁻²) and enhanced photoresponsivity (210 μA W⁻¹), at a lower bias potential in alkaline solution, of the Bi₂S₃ nanosheet-based photodetector are achieved, compared with those of other 2D nanomaterial-based photodetectors under light irradiation. Furthermore, the as-prepared Bi₂S₃ nanosheet-based photodetector not only exhibits an appropriate capacity of self-driven broadband and high-performance photoresponse but also displays strong long-term stability of the ON/OFF switching behaviour without any external protection in alkaline solutions. Because of facile synthesis via a LPE method, a higher photocurrent density and photoresponsivity, self-driven performance and long-term stability of the Bi₂S₃ nanosheet-based photodetector at a lower bias potential in alkaline solutions, the present work can provide fundamental acknowledgement of the high performance of this new kind of PEC-type 2D nanosheet-based photodetector.

Wearable optical fiber sensors have great potential for development in medical monitoring. With the increasing demand for compactness, comfort, accuracy, and other features in new medical monitoring devices, the development of wearable optical fiber sensors is increasingly meeting these requirements. This paper reviews the latest evolution of wearable optical fiber sensors in the medical field. Three types of wearable optical fiber sensors are analyzed: wearable optical fiber sensors based on Fiber Bragg grating, wearable optical fiber sensors based on light intensity changes, and wearable optical fiber sensors based on Fabry–Perot interferometry. The innovation of wearable optical fiber sensors in respiration and joint monitoring is introduced in detail, and the main principles of three kinds of wearable optical fiber sensors are summarized. In addition, we discuss their advantages, limitations, directions to improve accuracy and the challenges they face. We also look forward to future development prospects, such as the combination of wireless networks which will change how medical services are provided. Wearable optical fiber sensors offer a viable technology for prospective continuous medical surveillance and will change future medical benefits.

All-optical modulators fully manipulating one light by another light in the photonics domain have attracted great research interest in optical interconnects, optical communication networks etc. By employing an all-fiber Michelson interferometer, an all-optical phase and intensity modulator based on the excellent photothermal effect of few-layer bismuthene, for the first time, has been designed and successfully verified with multifunctional properties, including phase shifting, wavelength tuning, intensity modulating and information loading. Besides these multifunctional properties, it possesses a high conversion efficiency, excellent wavelength-tunable precision, large modulation depth and switchable output logic. We believe that this multifunctional all-optical modulator provides fundamental guidance on the design of all-optical systems with the fewest types of basic devices. It is therefore anticipated that this contribution will promote the development of two dimensional nanomaterial-based all-optical modulators towards all-optical communication and computing in the future.