Spontaneous Particle Ordering, Sorting, and Assembly on Soap Films.

Soap bubbles exhibit abundant fascinating phenomena throughout the entire life of evolution with different fundamental physics governing them. Nevertheless, the complicated dynamics of small objects in soap films are still unrevealed. Here, we report the first observation of spontaneous particle ordering in a complicated galaxy of soap films without any external energy. The balance of interfacial tension at two liquid-gas interfaces is theoretically predicted to govern belted wetted particles (BWPs) traveling along a specified path spontaneously. Such spontaneous particle path-finding is found to depend on the particle size and hydrophilic properties. Spontaneous particle sorting is directly realized via these discrete and distinctive paths for different particles. The deformation of the soap membrane facilitates 1D/2D particle organization along the path. This observation represents the discovery of a new spontaneous order phenomenon in soap film systems and provides a new energy-free approach for particle separation and soft colloidal crystal assembly.

Self-Powered and Broadband Photodetectors Based on High-performance Mixed Dimensional Sb2O3/PdTe2/Si Heterojunction for Multiplex Environmental Monitoring.

Solar-blind ultraviolet (SBUV) to near-infrared (NIR) broadband photodetectors (BB-PD) have important applications in environmental monitoring and other applications. However, it is challenging to prepare SBUV-IR photosensitive materials via simple steps and to construct SBUV-IR broadband devices for multiplex detection with high sensitivity at different wavelengths. Here, self-powered and broadband photodetectors using a high-performance mixed dimensional Sb2O3 nanorod 1-dimension (1D)/monodisperse microdiamond-like PdTe2 3-dimension (3D)/Si (3D) heterojunction for multiplex detection of environmental pollutants with high sensitivity at broadband wavelength are developed. The 1D/3D mixed dimensional Sb2O3/PdTe2/Si structure combines the advantages of strong light absorption, high carrier transport efficiency of 1D Sb2O3 nanorods, and expansion of interface barrier caused by 3D microdiamond-like PdTe2 interlayer to improve the photocurrent density and self-powered ability. The efficient photogenerated charge separation enables anon/off ratio of more than 5 × 106. The device exhibits excellent photoelectric properties from 255 to 980 nm with the responsivity from 4.56 × 10-2 to 6.55 × 10-1 AW-1, the detectivity from 2.36 × 1012 to 3.39 × 1013 Jones, and the sensitivity from 3.90 × 107 to 1.10 × 1010 cm2 W-1 without external bias. Finally, the proposed device is applied for the multiplex monitoring of environmental pollution gases NO2 with the detection limit of 200 ppb and PM2.5 particles at mild pollution at broadband wavelength. The proposed BB-PD has great potential for multiplex detection of environmental pollutants and other analytes at broadband wavelength.

Nanoplasmonic sensors for extracellular vesicles and bacterial membrane vesicles.

Extracellular vesicles (EVs) are promising tools for the early diagnosis of diseases, and bacterial membrane vesicles (MVs) are especially important in health and environment monitoring. However, detecting EVs or bacterial MVs presents significant challenges for the clinical translation of EV-based diagnostics. In this Review, we provide a comprehensive discussion on the basics of nanoplasmonic sensing and emphasize recent developments in nanoplasmonics-based optical sensors to effectively identify EVs or bacterial MVs. We explore various nanoplasmonic sensors tailored for EV or bacterial MV detection, emphasizing the application of localized surface plasmon resonance through gold nanoparticles and their multimers. Additionally, we highlight advanced EV detection techniques based on surface plasmon polaritons using plasmonic thin film and nanopatterned structures. Furthermore, we evaluate the improved detection capability of surface-enhanced Raman spectroscopy in identifying and classifying these vesicles, aided by plasmonic nanostructures. Nanoplasmonic sensing techniques have remarkable precision and sensitivity, making them a potential tool for accurate EV detection in clinical applications, facilitating point-of-care molecular diagnostics. Finally, we summarize the challenges associated with nanoplasmonic EV or bacterial MV sensors and offer insights into potential future directions for this evolving field.

Experimental study on soil improvement by electrochemical injection of calcium chloride solutions with time interval.

An improved electroosmotic method is proposed in this paper to enhance the non-uniform effect and efficiency of electroosmotic process. Such method is electroosmotic flow with injection of calcium chloride through the anode, followed by injection through the central tube (a tube at the midpoint between the anode and the cathode) with a suitable time interval between injections. Experimental results indicate that using this method can significantly improve the non-uniform reduction in water content throughout the soil, mitigate the formation of cracks in the anode section, and therefore considerably inhibit the increase in the electric resistance. After treatment, the drained water could be raised to 3.59 times more than that of pure electroosmotic flow, and 1.3 times that of simultaneous injection through both the anode and the central tube with considerably slight increase in power consumption. Moreover, the area of cementation was also expanded, approximately twice larger than that of pure electroosmotic flow and one and a half that of simultaneous injection. It is also worth noting that the proposed method performs better with the same power consumption. The results demonstrate that electroosmotic flow with a suitable time interval between injections could improve the efficiency of electroosmotic process and expand the treatment region in soils, hence can be a promising and economic technique for soil improvement in practical engineering.