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Multi‐dimensional force sensing that combines intensity, location, area and the like could gather a wealth of information from mechanical stimuli. Developing materials with force‐induced optical and electrical dual responses would provide unique opportunities to multi‐dimensional force sensing, with electrical signals quantifying the force amplitude and the luminescence output providing spatial distribution of force. However, the reliance on external power supply and high‐energy excitation source brings significant challenges to the applicability of multi‐dimensional force sensors. Here we reported the mechanical energy‐driven and sunlight‐activated materials with force‐induced dual responses, and investigated the underlying mechanisms of self‐sustainable force sensing. Theoretical analysis and experimental data unraveled that trap‐controlled luminescence and interfacial electron transfer play a major role in force‐induced optical and electrical output. These materials were manufactured into pressure sensor with renewable dual‐mode output for quantifying and visualization of pressures by electrical and optical output, respectively, without power supply and high‐energy irradiation. The quantification of tactile sensation and stimuli localization of mice highlighted the multi‐dimensional sensing ability of the sensor. Overall, this self‐powered pressure sensor with multimodal output provides more modalities of force sensing, poised to change the way that intelligent devices sense with the world. [ABSTRACT FROM AUTHOR]

Monitoring microbial metabolism is vital for biomanufacturing processes optimization. However, it remains a grand challenge to offer insight into microbial metabolism due to particularly complex and dynamic processes. Here, we report an electron‐sensing probe Zn2GeO4:Mn@Fe3+ for real‐time and dynamic monitoring of Fe(III) respiration metabolism. The quenched persistent luminescence of Zn2GeO4:Mn@Fe3+ is recovered when Fe3+ accepted electrons from the dynamic Fe(III) respiration metabolism, enabling the real‐time monitoring of microbial metabolism. The probe shows the capability to verify the role of related biomolecules in microbial Fe(III) respiration metabolism, to track the dynamic Fe(III) respiration metabolic response to environmental stress and microbial co‐culture interactions. Furthermore, the Zn2GeO4:Mn@Fe3+ probe provides guidance for improving biosynthesis efficiency by monitoring Fe redox recycling in microbial co‐culture. [ABSTRACT FROM AUTHOR]

Persistent luminescence materials (PLMs) are a class of unique luminescent materials that can remain luminescent for a few milliseconds to days without constant excitation. By virtue of the super long decay time, PLMs have been extensively explored in biosensing and bioimaging applications to elimin ate autofluorescence interference and improve signal‐to‐noise ratio in complex samples and tissues. However, nude PLMs often suffer from the poor stability, selectivity, and biocompatibility in biological system and in vivo, which greatly impedes their applications in biomedicine and bioanalysis. Remarkably, surface modification is a viable solution that endows PLMs with span‐new features and can make PLMs suitable for organisms by altering PLMs' interaction with biological system. In this review, commonly used strategies for surface modification of PLMs are briefly introduced, and the applications of surface modified PLMs in biosensing and bioimaging as well as their challenges are summarized. [ABSTRACT FROM AUTHOR]

We have previously reported the inhibition of bacterial topoisomerase I activity by a fluoroquinophenoxazine compound (FP-11g) with a 6-bipiperidinyl lipophilic side chain that exhibited promising antituberculosis activity (MIC = 2.5 μM against Mycobacterium tuberculosis, SI = 9.8). Here, we found that the compound is bactericidal towards Mycobacterium smegmatis, resulting in greater than 5 Log10 reduction in colony-forming units [cfu]/mL following a 10 h incubation at 1.25 μM (4X MIC) concentration. Growth inhibition (MIC = 50 μM) and reduction in cfu could also be observed against a clinical isolate of Mycobacterium abscessus. Stepwise isolation of resistant mutants of M. smegmatis was conducted to explore the mechanism of resistance. Mutations in the resistant isolates were identified by direct comparison of whole-genome sequencing data from mutant and wild-type isolates. These include mutations in genes likely to affect the entry and retention of the compound. FP-11g inhibits Mtb topoisomerase I and Mtb gyrase with IC50 of 0.24 and 27 μM, respectively. Biophysical analysis showed that FP-11g binds DNA as an intercalator but the IC50 for inhibition of Mtb topoisomerase I activity is >10 fold lower than the compound concentrations required for producing negatively supercoiled DNA during ligation of nicked circular DNA. Thus, the DNA-binding property of FP-11g may contribute to its antimycobacterial mechanism, but that alone cannot account for the observed inhibition of Mtb topoisomerase I. [ABSTRACT FROM AUTHOR]

Two novel lanthanide metal–organic framework (Ln‐MOF) luminescent sensors for the detection of picric acid have been successfully assembled. Following a function‐oriented strategy, urea hydrogen‐bonding functional sites were introduced into two MOF frameworks. A structural analysis indicated that the two MOFs have the exact same structure, namely 2D layers with diamond‐shaped holes that are accumulated into a 3D framework through the hydrogen‐bonding interactions between urea and carboxylate groups. Interestingly, only half of the urea units are involved in supporting the MOF framework through N−H⋅⋅⋅O hydrogen‐bonding interactions, whereas the other half are located in the pore channel and act as empty recognition sites. Abundant N−H urea bonds are present in the inner walls of three types of interpenetrating 1D channels. Luminescence studies revealed that the two Ln‐MOFs exhibit high sensitivity, good selectivity, and a fast luminescence quenching response towards picric acid. In particular, the two Ln‐MOFs can be simply and quickly regenerated, and exhibit excellent recyclability. In summary, we have successfully used a function‐oriented strategy to achieve multiple functions in a ligand to construct lanthanide MOF luminescent sensors for the detection of picric acid, thereby providing a potential strategy for the future development of MOF luminescent sensors with a specific target. Explosive detection: Following a function‐oriented strategy, two novel lanthanide metal–organic framework luminescent sensors containing dual‐function urea hydrogen‐bond sites have been successfully assembled, and because of the N−H urea bonds in the inner walls of three types of interpenetrating 1D channels, they exhibit high sensitivity, good selectivity, and a fast luminescence quenching response towards picric acid (see figure). [ABSTRACT FROM AUTHOR]

Abstract: The blue phosphor Ba0.9 Mg0.98Al10O17:0.1Eu2+, 0.02Mn2+ (BAM:Eu2+, Mn2+) was prepared by flux assisted solid-state reaction method. The effects of (NH4)2CO3 and LiF on the morphology and luminescent properties were studied. The usually obtained BAM:Eu2+, Mn2+ particles had hexagonal shape. We found that the thickness of the particle was affected by the amount of LiF and spherical-like particles can be obtained. The significant change on morphology from plate-like to spherical-like shape led to a highly enhanced luminescence of BAM:Eu2+, Mn2+. The maximum luminance intensity of prepared samples was 108% in comparison with the commercial BAM:Eu2+, Mn2+ under UV excitation. [Copyright &y& Elsevier]

Abstract: Novel red phosphors Na2CaSiO4:xEu3+ were synthesized using high temperature solid-state reaction and their luminescence characteristics were investigated for the first time. The excitation spectra indicate that the Na2CaSiO4:xEu3+ phosphors can be effectively excited by ultraviolet (393nm) light. The emission spectra of Na2CaSiO4:xEu3+ phosphors invariably exhibit four peaks assigned to the 5D0–7F J (J =1, 2, 3 and 4) transitions of Eu3+ under 393nm excitation. The Commission Internationale de l’Eclairage (CIE) chromaticity coordinates and quantum efficiency (QE) are (0.66, 0.34) and 58.9%, respectively. The good color saturation and high quantum efficiency indicate that Na2CaSiO4:Eu3+ phosphors are potential candidate for light-emitting diodes. [Copyright &y& Elsevier]

Abstract Room-temperature electroluminescence spectra of InGaN/GaN multiple quantum well (MQW) structures grown on sapphire substrate by metalorganic chemical vapor deposition (MOCVD) were investigated. It is found that, in comparison with the same-temperature growth of MQW layers, GaN barrier layers grown at a temperature higher than the well layer growth of 790 °C are beneficial to improve the emission intensity of InGaN/GaN MQWs. The XRD and AFM measurements show a better interface quality and less non-radiative recombination centers (trench defects) exist in the dual-temperature-grown InGaN MQWs between InGaN well and GaN barrier layers. In addition, increasing barriers growth temperature will induce less concentration of deeper localization states which may contribute to a blue shift of EL emission wavelength. Highlights • Dual-temperature-grown InGaN/GaN quantum wells improve the emission intensity significantly. • Increasing GaN barriers growth temperature reduces deep localization states. • High quality GaN barriers help InGaN wells reduce trench defects. [ABSTRACT FROM AUTHOR]

The luminescence characteristics of InGaN ultra-thin films with and without GaN cap layer are investigated by temperature-dependent photoluminescence (TDPL) measurements. It is experimentally observed that, during the TDPL measurements at some fixed temperatures, the PL spectra of bare InGaN film show anomalous attenuation and redshift with time passing. This may be attributable to the enhancement of quantum-confined Stark effect in InGaN layer due to the desorption of the negatively charged particles on the surface of bare InGaN film, because the adsorbed negative charges on InGaN surface partially counteract the piezoelectric field in the ultra-thin InGaN film. However, for the GaN-capped InGaN ultra-thin film, those anomalous spectral variations with time vanish, as the adsorption and desorption process on the InGaN surface are screened by the GaN cap layer. [ABSTRACT FROM AUTHOR]