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Microorganisms such as pathogenic bacteria, fungi, and viruses pose a serious threat to human health and society. Surfaces are one of the major pathways for the transmission of infectious diseases. Therefore, imparting antipathogenic properties to these surfaces is significant. Here, we present a rapid, one-step approach for practical fabrication of antimicrobial and antifungal surfaces using an eco-friendly and low-cost reducing agent, the extract of Cedrus libani . Copper oxide nanoparticles were grown in situ on the surface of print paper and fabric in the presence of the copper salt and extract, without the use of any additional chemicals. The morphology and composition of the grown nanoparticles were characterized using field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction techniques. The analysis revealed that the grown particles consist of mainly spherical CuO nanoparticles with an average size of ∼14 nm and its clusters with an average size of ∼700 nm. The in situ growth process enables strong bonding of the nanoparticles to the surface, resulting in enhanced durability against wear and tear. Moreover, the fabricated surface shows excellent growth inhibition ability and bactericidal activity against both gram-negative and gram-positive bacteria, Escherichia coli and Staphylococcus aureus , as well as antifungal activity against Candida albicans , a common pathogenic fungus. The ability to grow copper oxide nanoparticles on different surfaces paves the way for a range of applications in wound dressings, masks, and protective medical equipment.

contact angle (>150°) and readily roll off at low sliding angles. [1][2][3] Popularized by the discovery and elucidation of selfcleaning mechanism of lotus leaves, [4,5] superhydrophobic surfaces have attracted significant attention for practical applications such as self-cleaning solar cells, [6][7][8] corrosion inhibition layers on metal surfaces, [9,10] anti-icing coatings, [11,12] and oil/water separation membranes and meshes. [13][14][15] Superhydrophobic surfaces have been adopted in a number of niche applications such as blood-repellent garments, [16] anti-biofouling coatings, [17,18] and to concentrate molecules for bio-assay analysis and increase detection limit. [19,20] Superhydrophobic surfaces feature heterogeneous morphology with nanoscopic and microscopic roughness in the form of protrusions separated by air pockets and are generally fabricated by using low surface energy materials. [21] The combination of nano/micro-scale protrusions with low surface energy leads to diminished adhesion and improved droplet mobility.The excessive usage of solvents and toxic chemicals, long and tedious chemical processes, limited biocompatibility, and costly materials are challenges in the sustainable fabrication of superhydrophobic surfaces. A convenient and universal method, also adapted in commercialThe broad adoption of superhydrophobic surfaces in practical applications is hindered by limitations of existing methods in terms of excessive usage of solvents, the need for tedious and lengthy chemical processes, insufficient biocompatibility, and the high cost of materials. Herein, a mechanochemical approach for practical and solvent-free manufacturing of superhydrophobic surfaces is reported. This approach enables solvent-free and ultra-rapid preparation of superhydrophobic surfaces in a single-step without the need for any washing, separation, and drying steps. The hydrolytic rupture of siloxane bonds and generation of free radicals induced by mechanochemical pathways play a key role in covalent grafting of silicone to the surface of nanoparticles that leads to superhydrophobic surfaces with a water contact angle of >165° and a sliding angle of <2°. The direct use of industrially available and nonfunctional silicone materials together with demonstrated applicability to inorganic nanoparticles of varied composition greatly contribute to the scalability of the presented approach. The resulting superhydrophobic surfaces are highly biocompatible as demonstrated by fibroblast cells using two different assays. Monolith materials fabricated from silicone-grafted nanoparticles exhibit bulk and durable superhydrophobicity. The presented approach offers tremendous potential with sustainability, scalability, cost-effectiveness, simplicity, biocompatibility, and universality.

The demand for encoded surfaces has increased significantly over the past decade driven by the rapid digitalization of the world. Surface‐enhanced Raman scattering (SERS) offers unique capabilities in generation of encoded surfaces. The challenge is the limited versatility of SERS‐based encoding systems in terms of the applicable surfaces. This study addresses this challenge by using a temporary tattoo approach together with simplified fabrication of SERS‐active patterns by ink‐jet printing of a particle‐free reactive silver ink. Plasmonic silver nanostructures form on the tattoo paper upon ink‐jet printing and a brief thermal annealing. The SERS activity is sufficient to detect taggant molecules of rhodamine 6G, methylene blue, and rhodamine B with a nanomolar level sensitivity. Raman‐active taggants can be incorporated into the ink, for drop‐on‐demand patterning of multiple molecules in 1D and 2D barcode geometries. The SERS barcodes can be effectively transferred to a range of different substrates retaining high plasmonic activity and geometric integrity. The presented approach decouples the SERS‐active pattern preparation from the final substrate and greatly improves the versatility of the barcodes.

Bacteria cause many common infections and are the culprit of many outbreaks throughout history that have led to the loss of millions of lives. Contamination of inanimate surfaces in clinics, the food chain, and the environment poses a significant threat to humanity, with the increase in antimicrobial resistance exacerbating the issue. Two key strategies to address this issue are antibacterial coatings and effective detection of bacterial contamination. In this study, we present the formation of antimicrobial and plasmonic surfaces based on Ag–Cu x O nanostructures using green synthesis methods and low-cost paper substrates. The fabricated nanostructured surfaces exhibit excellent bactericidal efficiency and high surface-enhanced Raman scattering (SERS) activity. The Cu x O ensures outstanding and rapid antibacterial activity within 30 min, with a rate of >99.99% against typical Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacteria. The plasmonic Ag nanoparticles facilitate the electromagnetic enhancement of Raman scattering and enables rapid, label-free, and sensitive identification of bacteria at a concentration as low as 103 cfu/mL. The detection of different strains at this low concentration is attributed to the leaching of the intracellular components of the bacteria caused by the nanostructures. Additionally, SERS is coupled with machine learning algorithms for the automated identification of bacteria with an accuracy that exceeds 96%. The proposed strategy achieves effective prevention of bacterial contamination and accurate identification of the bacteria on the same material platform by using sustainable and low-cost materials.

Access to clean water is a pressing challenge affecting millions of lives and the aquatic body of the Earth. Sensitive detection of pollutants such as pesticides is particularly important to address this challenge. This study reports eco-friendly preparation of the surface-enhanced Raman scattering (SERS) substrate for machine learning-assisted detection of pesticides in water. The proposed SERS platform was prepared on a copy paper by reducing a silver salt using the extract of a natural plant, Cedrus libani. The fabricated SERS platform was characterized in detail using scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The high-density formation of silver nanoparticles with an average diameter of 41 nm on the surface of the paper enabled detection of analytes with a nanomolar level sensitivity. This SERS capability was used to collect Raman signals of four different pesticides in water: myclobutanil, phosmet, thiram, and abamectin. Raman spectra of the pesticides are highly complex, challenging accurate determination of the pesticide type. To overcome this challenge and distinguish pesticides, machine learning (ML) approach was used. The ML-mediated detection of harmful pesticides on a versatile, green, and inexpensive SERS platform appears to be promising for environmental applications.

Transferrable SERS Barcodes In article number 2200048, Furkan Sahin, Mustafa Serdar Onses, and co‐workers introduce a new approach for the fabrication of security labels that is derived from the combined use of a temporary tattoo approach and ink‐jet printing of a particle‐free reactive silver inks. The resulting barcodes exhibit high SERS activity and can be effectively transferred to a range of different objects such as paintings, chips, and coins.