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Metal halide perovskite quantum dots (QDs) with unique physicochemical properties are promising candidates for next-generation optoelectronics, but they often suffer from stability issues that severely limit their potential for practical applications. In this work, we adopt an oleic acid/oleylamine-free approach to synthesize MAPbBr3 quantum dot (MQD) papers by incorporating MQDs into cellulose nanofiber frameworks. The abundant long-chain binding ligands containing sulfate terminal groups within the cellulose nanofiber remarkably stabilize the MQD structure, enabling the fabrication of self-power and flexible MQD paper photodetectors with a responsivity of ∼0.19 mA W−1, detectivity of 1.58 × 108 cm Hz1/2 W−1, and excellent bendability and reliability after 500 bending cycles. More importantly, these MQD/cellulose-based self-powered photodetectors demonstrate extraordinarily high environmental stability, maintaining more than 90% of the initial responsivity after 60 days. The simple disposability of the paper-based device is also illustrated by burning within one second, suggesting the ease of device elimination. Our work provides a unique approach to designing ultra-stable perovskite QD-based electronics with unprecedented functionalities. [ABSTRACT FROM AUTHOR]

We report epitaxially grown new two-dimensional metal–organic framework (MOF) thin films on a self-assembled monolayer (SAM). We fabricated these epitaxial thin-films using stepwise layer-by-layer seeding followed by solvothermal treatment. The MOF thin films exhibit ultrafast structural flexibility (through breathing) compared to their bulk samples upon uptake of organic guest molecules. [ABSTRACT FROM AUTHOR]

Although droplet microfludics is a promising technology for handling a number of liquids of a single type of analyte, it has limitations in handling thousands of different types of analytes for multiplex assay. Here, we present a novel “liquid-capped encoded microcapsule”, which is applicable to various liquid format assays. Various liquid drops can be graphically encoded and arrayed without repeated dispensing processes, evaporation, and the risk of cross-contamination. Millions of nanoliter-scale liquids are encapsulated within encoded microcapsules and self-assembled in microwells in a single dispensing process. The graphical code on the microcapsule enables identification of randomly assembled microcapsules in each microwell. We conducted various liquid phase assays including enzyme inhibitor screening, virus transduction, and drug-induced apoptosis tests. The results showed that our liquid handling technology can be utilized widely for various solution phase assays. [ABSTRACT FROM AUTHOR]

Shape-encoded silica microparticles for use in multiplexed bioassays were fabricated by using optofluidic maskless lithography (OFML) and tetraethylorthosilicate (TEOS) polymerization. These encoded silica microparticles exhibit excellent bioconjugation properties and negligible non-specific analyte adsorption. Encoded silica microparticles could be useful in a wide variety of applications, including DNA- and protein-based diagnostics. [ABSTRACT FROM AUTHOR]

This study demonstrates a simple approach for fabricating a 3D-μPAD from a single sheet of paper by double-sided printing and lamination. First, a wax printer prints vertically symmetrical and asymmetrical wax patterns onto a double-sided paper surface. Then, a laminator melts the printed wax patterns to form microfluidic channels in the paper sheet. The vertically symmetrical wax patterns form vertical channels when the melted wax patterns make contact with each other. The asymmetrical wax patterns form lateral and vertical channels at the cross section of the paper when the printed wax patterns are melted to a lower height than the thickness of the single sheet of paper. Finally, the two types of wax patterns form a 3D microfluidic network to move fluid laterally and vertically in the single sheet of paper. This method eliminates major technical hurdles related to the complicated and tedious alignment, assembly, bonding, and punching process. This 3D-μPAD can be used in a multiplex digital assay to measure the concentration of a target analyte in a sample solution simply by counting the number of colored bars at a fixed time. It does not require any external instruments to perform digital measurements. Therefore, we expect that this approach could be an instrument-free assay format for use in developing countries. [ABSTRACT FROM AUTHOR]

Correction for 'Organic guest molecule induced ultrafast breathing of an epitaxially grown metal–organic framework on a self-assembled monolayer' by Purna Chandra Rao et al., Chem. Commun., 2021, DOI: 10.1039/d1cc03721h. [ABSTRACT FROM AUTHOR]

Correction for 'Liquid-capped encoded microcapsules for multiplex assays' by Younghoon Song et al., Lab Chip, 2017, DOI: URL10.1039/c6lc01268j/URL. [ABSTRACT FROM AUTHOR]

Metal-free photoredox-catalyzed carbocarboxylation of various styrenes with carbon dioxide (CO2) and amines to obtain γ-aminobutyric ester derivatives has been developed (up to 91% yield, 36 examples). The radical anion of (2,3,4,6)-3-benzyl-2,4,5,6-tetra(9H-carbazol-9-yl)benzonitrile (4CzBnBN) possessing a high reduction potential (-1.72 V vs. saturated calomel electrode (SCE)) easily reduces both electron-donating and electron-withdrawing group-substituted styrenes.