Although radiotherapy is a general oncology treatment and is often synergistically applied with surgery and chemotherapy, it can cause side effects during and after treatment. Gold nanoparticles were studied as a potential material to enhance radiation to induce damage in cancer cells. However, few studies have been conducted to examine the effects of gold nanofilm on cell impairment under X-ray treatment. This paper describes a microfabrication-based single-cell array platform to evaluate DNA damage induced by enhanced X-ray radiation on gold nanofilm patches (GNFPs). Cancer cells were patterned on GNFPs of different diameters and thicknesses, where each cell was attached on one GNFP. The end-point DNA damage induced by X-ray was examined in situ at the single-cell level using a halo assay. The preliminary data demonstrated that the enhancement of DNA damage was significantly related to the area and thickness of the GNFP. This platform may be hopefully used to establish the mathematical relationships among DNA damage, X-ray dosage, and thickness and area of the GNFP, and further contribute to radiation dosage screening for personalized radiotherapy.

Nanomaterials have shown tremendous potentials to impact the broad field of biological sensing. Nanomaterials, with extremely small sizes and appropriate surface modifications, allow intimate interaction with target biomolecules. [...].

This article describes a paper-based low cost single cell HaloChip assay that can be used to assess drug- and radiation-induced DNA damage at point-of-care. Printing ink on paper effectively blocks fluorescence of paper materials, provides high affinity to charged polyelectrolytes, and prevents penetration of water in paper. After exposure to drug or ionizing radiation, cells are patterned on paper to create discrete and ordered single cell arrays, embedded inside an agarose gel, lysed with alkaline solution to allow damaged DNA fragments to diffuse out of nucleus cores, and form diffusing halos in the gel matrix. After staining DNA with a fluorescent dye, characteristic halos formed around cells, and the level of DNA damage can be quantified by determining sizes of halos and nucleus with an image processing program based on MATLAB. With its low fabrication cost and easy operation, this HaloChip on paper platform will be attractive to rapidly and accurately determine DNA damage for point-of-care evaluation of drug efficacy and radiation condition.

Two-dimensional (2D) barcodes ubiquitously used to label, track and authenticate objects face increasing challenges of being damaged, altered and falsified. The past effort in nanomaterials has paved the way for controlled synthesis of nanomaterials with desired size, shape and function. Due to their extremely small sizes, these nanomaterials are promising as next generation barcodes that can be added into or mixed with objects of interest without being noticed. These barcodes can be effectively read owing to their physical properties by manufacturers, law enforcement and security agencies. Meanwhile, nanomaterial-based barcodes are hard to reverse-engineer or imitate without advanced knowledge and technical expertise. This review describes how nanomaterials can be used as barcodes, discusses advantages and limitations of each type of nanomaterial-based barcode, and points out ways that could help design and prepare better nanomaterial-based barcodes.

Metal‐free carbonaceous materials have attracted considerable interests as heterogeneous catalysts owing to their superior physiochemical properties over metal‐based catalysts, such as low cost, no pollution, chemical and thermal stabilities, as well as readily tailorable porous structure and surface chemistry. This review article provides an overview of the fundamentals and recent advances in the field of metal‐free carbon catalysts, including graphenes, carbon nanotubes, mesoporous carbons, graphitic carbon nitrides, and related composites. Special focus is placed on their controllable preparation and applications in gas phase, liquid phase, electrochemical, and photocatalytic reactions, as well as defect and surface chemistry related catalytic activities of carbon materials. Some perspectives are highlighted on the development of more efficient metal‐free carbonaceous catalysts featuring high stability, low cost, optimized structures, and enhanced performance, which are the key factors to accelerate the designed preparation and commercialization of carbocatalysts.

There is an urgent need to develop in-product covert barcodes for anti-counterfeiting of agrochemicals. This paper reports a new organic nanoparticle-based in-product barcode system, in which a panel of organic phase change nanoparticles is added as a barcode into in a variety of chemicals (herein agrochemicals). The barcode is readout by detecting melting peaks of organic nanoparticles using differential scanning calorimetry. This method has high labeling capacity due to small sizes of nanoparticles, sharp melting peaks, and large scan range of thermal analysis. The in-product barcode can be effectively used to protect agrochemical products from being counterfeited due to its large coding capacity, technical readiness, covertness, and robustness.