This Communication describes polarity inversion in molecular rectification and the related mechanism. Using a supramolecular engineered, ultrastable, binary-mixed self-assembled monolayer (SAM) composed of an organic molecular diode (SCBIPY) and an inert reinforcement molecule (SC), we probed a rectification ratio ()-voltage relationship over an unprecedentedly wide voltage range (up to |3.5 V|) with statistical significance. We observed positive polarity in rectification at |1.0 V| ( = 107), followed by disappearance of rectification at ∼|2.25 V|, and then eventual emergence of new rectification with the opposite polarity at ∼|3.5 V| ( = 0.006; 1/ = 162). The polarity inversion occurred with a span over 4 orders of magnitude in . Low-temperature experiments, electronic structure analysis, and theoretical calculations revealed that the unusually wide voltage range permits access to molecular orbital energy levels that are inaccessible in the traditional narrow voltage regime, inducing the unprecedented inversion of polarity.
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January 2025
Institute of Biomass and Function Materials & National Demonstration Centre for Experimental Light Chemistry Engineering Education, College of Bioresources Chemistry and Materials Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, P. R. China.
As skin bioelectronics advances, hydrogel wearable devices have broadened perspectives in environment sensing and health monitoring. However, their application is severely hampered by poor mechanical and self-healing properties, environmental sensitivity, and limited sensory functions. Herein, inspired by the hierarchical structure and unique cross-linking mechanism of hagfish slime, a self-powered supramolecular hydrogel is hereby reported, featuring high stretchability (>2800% strain), ultrafast autonomous self-healing capabilities (electrical healing time: 0.
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January 2025
School of Chemistry and Chemical Engineering, Shandong University Jinan 250100 PR China
Noncovalent forces have a significant impact on photophysical properties, and the flexible employment of weak forces facilitates the design of novel luminescent materials with a variety of applications. The arene-perfluoroarene (AP) force, as one type of π-hole/π interaction, shows unique directionality, involving an electron-deficient π-hole interacting with a π-electron-rich region, facilitating precise orientation and stabilization in supramolecular structures. Here we present an amination engineering protocol to build a perfluoroarene library based on an octafluoronaphthalene skeleton with various steric and electronic properties.
View Article and Find Full Text PDFFront Robot AI
January 2025
CREATE Lab, Institute of Mechanical Engineering, School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
Laboratory automation requires reliable and precise handling of microplates, but existing robotic systems often struggle to achieve this, particularly when navigating around the dynamic and variable nature of laboratory environments. This work introduces a novel method integrating simultaneous localization and mapping (SLAM), computer vision, and tactile feedback for the precise and autonomous placement of microplates. Implemented on a bi-manual mobile robot, the method achieves fine-positioning accuracies of 1.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
National University of Singapore - Kent Ridge Campus: National University of Singapore, Department of Chemistry, Faculty of Science, 3 Science Drive 3, 117543, Singapore, SINGAPORE.
Figure-eight macrocycles represent a fascinating class of π-conjugated units characterized by unique aesthetics and non-contact molecular crossing at the center. Despite progress in synthesis over the past century, research into inorganic, organic, and polymeric figure-eight materials remains in its infancy. Here we report the first examples of figure-eight covalent organic frameworks by condensing figure-eight knots to create extended porous figure-eight π architectures.
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March 2025
Department of Biomedical Engineering, College of Design and Engineering, National University of Singapore, 15 Kent Ridge Crescent, Singapore 119276, Singapore; National University of Singapore (Suzhou) Research Institute, Suzhou, Jiangsu 215123, China; National University of Singapore (Chongqing) Research Institute, Yubei, Chongqing 401120, China; NUS Environmental Research Institute (NERI), National University of Singapore, 5A Engineering Drive 1, Singapore 117411, Singapore. Electronic address:
The combination of chemotherapy and gene therapy holds promise in treating cancer. A key strategy is to use small interfering RNAs (siRNAs) to silence programmed death-ligand 1 (PD-L1) expression in cancer cells, disrupting tumor immune evasion and enhancing anticancer treatments, particularly when used in conjunction with chemotherapy drugs such as doxorubicin (Dox). However, effective codelivery of drugs and genes requires carefully designed carriers and complex synthesis procedures.
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