Combining printing and nanoparticle assembly: Methodology and application of nanoparticle patterning

Emerging contaminants: A One Health perspective

Environmental pollution is escalating due to rapid global development that often prioritizes human needs over planetary health. Despite global efforts to mitigate legacy pollutants, the continuous introduction of new substances remains a major threat to both people and the planet. In response, global initiatives are focusing on risk assessment and regulation of emerging contaminants, as demonstrated by the ongoing efforts to establish the UN's Intergovernmental Science-Policy Panel on Chemicals, Waste, and Pollution Prevention. This review identifies the sources and impacts of emerging contaminants on planetary health, emphasizing the importance of adopting a One Health approach. Strategies for monitoring and addressing these pollutants are discussed, underscoring the need for robust and socially equitable environmental policies at both regional and international levels. Urgent actions are needed to transition toward sustainable pollution management practices to safeguard our planet for future generations.

Schottky infrared detectors with optically tunable barriers beyond the internal photoemission limit

Internal photoemission is a prominent branch of the photoelectric effect and has emerged as a viable method for detecting photons with energies below the semiconductor bandgap. This breakthrough has played a significant role in accelerating the development of infrared imaging in one chip with state-of-the-art silicon techniques. However, the performance of these Schottky infrared detectors is currently hindered by the limit of internal photoemission; specifically, a low Schottky barrier height is inevitable for the detection of low-energy infrared photons. Herein, a distinct paradigm of Schottky infrared detectors is proposed to overcome the internal photoemission limit by introducing an optically tunable barrier. This device uses an infrared absorbing material-sensitized Schottky diode, assisted by the highly adjustable Fermi level of graphene, which subtly decouples the photon energy from the Schottky barrier height. Correspondingly, a broadband photoresponse spanning from ultraviolet to mid-wave infrared is achieved, with a high specific detectivity of 9.83 × 1010 cm Hz1/2 W-1 at 2,700 nm and an excellent specific detectivity of 7.2 × 109 cm Hz1/2 W-1 at room temperature under blackbody radiation. These results address a key challenge in internal photoemission and hold great promise for the development of the Schottky infrared detector with high sensitivity and room temperature operation.

Nanoparticle Assembly: From Self-Organization to Controlled Micropatterning for Enhanced Functionalities

Nanoparticles form long-range micropatterns via self-assembly or directed self-assembly with superior mechanical, electrical, optical, magnetic, chemical, and other functional properties for broad applications, such as structural supports, thermal exchangers, optoelectronics, microelectronics, and robotics. The precisely defined particle assembly at the nanoscale with simultaneously scalable patterning at the microscale is indispensable for enabling functionality and improving the performance of devices. This article provides a comprehensive review of nanoparticle assembly formed primarily via the balance of forces at the nanoscale (e.g., van der Waals, colloidal, capillary, convection, and chemical forces) and nanoparticle-template interactions (e.g., physical confinement, chemical functionalization, additive layer-upon-layer). The review commences with a general overview of nanoparticle self-assembly, with the state-of-the-art literature review and motivation. It subsequently reviews the recent progress in nanoparticle assembly without the presence of surface templates. Manufacturing techniques for surface template fabrication and their influence on nanoparticle assembly efficiency and effectiveness are then explored. The primary focus is the spatial organization and orientational preference of nanoparticles on non-templated and pre-templated surfaces in a controlled manner. Moreover, the article discusses broad applications of micropatterned surfaces, encompassing various fields. Finally, the review concludes with a summary of manufacturing methods, their limitations, and future trends in nanoparticle assembly.

Particulate Standard Establishment for Absolute Quantification of Nanoparticles by LA-ICP-MS

The development of nanotechnology has transformed many cutting-edge studies related to single-molecule analysis into nanoparticle (NP) detection with a single-NP sensitivity and ultrahigh resolution. While laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been successful in quantifying and tracking NPs, its quantitative calibration remains a major challenge due to the lack of suitable standards and the uncertain matrix effects. Herein, we frame a new approach to prepare quantitative standards via precise synthesis of NPs, nanoscale characterization, on-demand NP distribution, and deep learning-assisted NP counting. Gold NP standards were prepared to cover the mass range from sub-femtogram to picogram levels with sufficient accuracy and precision, thus establishing an unambiguous relationship between the sampled NP number in each ablation and the corresponding mass spectral signal. Our strategy facilitated for the first time the study of the factors affecting particulate sample capture and signal transductions in LA-ICP-MS analysis and culminated in the development of an LA-ICP-MS-based method for absolute NP quantification with single-NP sensitivity and single-cell quantification capability. The achievements would herald the emergence of new frontiers cut across a spectrum of toxicological and diagnostic issues related to NP quantification.

A Separation-Sensing Platform Performing Accurate Diagnosis of Jaundice in Complex Biological Tear Fluids

The detection of biomarkers in tears has aroused great interest owing to the advantages of non-invasive and rapid collection. The combination of ultrasensitivity and label-free detection of surface-enhanced Raman spectroscopy (SERS) sensors is expected to achieve real-time diagnosis in home medical care. However, the surface of SERS sensors is susceptible to biofouling and inactivation by biological impurities in tears, resulting in rapid degradation of sensitivity, limiting the commercialization of point-of-care devices. Herein, a binary nanosphere array with dual properties is constructed as a separation-sensing platform for the diagnosis of target molecules in tears. The upper part of the structure is composed of Au nanoparticles (AuNPs) and a sputtering Au layer, which can bind the target molecules that interact with Au and provide high-strength and high-density SERS hotspots. The lower half is an inactive SiO₂ nanosphere array with periodic large pores that allows biological impurities to penetrate the lower part and be separated from the target analyte. Furthermore, this substrate was integrated into homemade tear kits, enabling simultaneous tear collection, pre-separation, and detection. Combined with the Raman spectra of tears and LDA analysis, we successfully identified patients with jaundice in clinics. This platform is expected to provide an opportunity for early disease screening based on biological fluids.