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[Display omitted] • 2D MXenes are the key materials in novel flexible electronic devices. • MXene-based electronics on various substrates (hydrogel, paper, etc.) are reviewed. • MXene-based electronics can be integrated with artificial intelligence. • Applications of MXenes in the new generation of wearable devices are summarized. • Challenges and difficulties in designing MXene-based electronics are discussed. • Future research directions are also suggested for wearable MXene electronics. Wearable electronic devices find increasing applications in mobile medical sensing and monitoring, human–computer interaction, and portable energy collection and storage, owing to their flexibility and stretchability. In recent years, transition metal nitrides and carbides, known as MXenes, have become cornerstones for the preparation of novel flexible electronic devices because of their excellent electrical conductivities, abundant surface functional groups, and large specific surface areas. This review presents the latest developments in MXene-based wearable electronic products, including hydrogels, paper, composite materials, and self-powered devices. These products can be integrated with artificial intelligence to show unique applications in healthcare, inspection, and control of human-like machines. The application prospects of MXenes in the new generation of wearable electronic devices are forecast, the challenges and difficulties in designing MXene-based wearable electronic devices are discussed, and corresponding solutions are suggested. This review also provides future research directions for the development of MXenes for pliable and wearable applications. [ABSTRACT FROM AUTHOR]

As an energy source for the new era and an excellent candidate for building self-powered energy equipment, triboelectric nanogenerators can absorb various forms of energy existing in the environment through transducer elements, realizing self-drive away from traditional energy sources. With simple structure, inexpensive, small size, strong biocompatibility and high instantaneous power density, it has become an attractive supporting technology in the field of Internet of Things. Triboelectric nanogenerator not only provides continuous energy for a variety of devices, but also reflect the health of the organism in real time when coupled to specific biochemical or physiological reactions. Considerable research has demonstrated that the design of TENG-based self-powered plants is an extremely promising strategy, especially in the field of life and health. With the rapid development of wearable and implantable devices, TENG can lay the foundation for these healthcare preparations from the low-frequency mechanical energy in the body. When it is attached to the surface or inside the body, like the heart, it provides a constant source of power for the operation of life in the continuous process of contact and separation. This review briefly introduces the basic working principle and mode of TENG, the latest application and research progress on the performance improvement of TENG-based self-powered equipment. The conclusion of is that TENG-based self-powered energy devices are an important development direction in the field of life and health in the future, laying the foundation for real-time and continuous in situ monitoring and treatment. [Display omitted] • This review introduces the latest application and research progress on the performance improvement of TENG-based self-powered equipment. • In response to the issue of TENG production, this paper discussed the exploration and efforts made by scientists in improving TENG performance. • Finally, the potential challenges and future development prospects that TENG is currently facing were discussed and summarized. [ABSTRACT FROM AUTHOR]

Monitoring of low-level analytes are typical examples for analytical challenges. Salbutamol (SAL), a phenol-β2-agonist, has a very low residual content in the environment. Here, we present an ultrasensitive complete antigen-bridged PCR assay for detecting salbutamol (SAL). These DNA probes modified SAL complete antigens target recognition SAL antibodies and agglutinate synthetic DNA conjugates, thus enabling ligation of DNA probes to form a full-length DNA amplicon that contained a recognition site for cleavage endonuclease and subsequent quantification by qPCR. Moreover, SAL antibodies were modified with magnetic beads which were used to reduce the background noise and sample matrix effect, and the DNA signals were isothermally amplified by strand displacement amplification technology. Some key parameters which influence assay performance were optimized: the length of the bridge oligonucleotide, the concentration of immunomagnetic beads, SAL probes, and initiation chain, etc. Under the optimum conditions, the signal amplification of proposed Immuno-PCR assay for the detection of SAL was exponential, resulting in high potential sensitivity(~1 fg/mL) and a broad detection dynamic range (> 105 fold). Using this proposed method, we detected SAL in spiked tap water and urine samples with acceptable recoveries ranging from 88.1 to 103.3%. Theoretically, the method developed here has broad applicability and practical utility in immunoassays of a wide variety of analytes. Unlabelled Image • Two complete antigen probes were used as bridges which agglutinate synthetic antibody-DNA conjugates. • A recognition site for DNA amplification was also formed by bridge of two complete antigen probes. • Functional immunomagnetic beads were used to reduce the background noise and the sample matrix effect for Immuno-PCR. • The signal amplification was exponential, resulting in high potential sensitivity and a broad detection dynamic range. [ABSTRACT FROM AUTHOR]

[Display omitted] • A speckle Ag-doped core–shell nanohybrids (Ag@CSNH) was developed as dual-mode probe. • A facile naked-eye and the fluorescence dual-mode immunosensor was developed. • The immunosensor was used for detection of OTA with LOD 0.9921 pg/mL. Ochratoxin A (OTA) is a potent carcinogen, and is among the most dangerous mycotoxins in agricultural products. In this study, an ultrasensitive dual-mode immunosensor was developed for naked-eye and fluorescence detection of OTA based on Ag-doped core–shell nanohybrids (Ag@CSNH). Complete antigen-labeled Ag@CSNH (CA-Ag@CSNH) were used as a competitive bind and dual-mode probe. The diffused doping structure of CA-Ag@CSNH provided improved stability, color and fluorescence quencher performance. Antibodies modified magnetic beads were used as a capture probe. The competitive binding between OTA and CA-Ag@CSNH produced both color change and fluorescence quenching. Ultraviolet and fluorescence intensitie correlated linearly with OTA concentration ranges of 0.03–3 ng/mL and 10–10000 pg/mL, and limits of detection of 0.0235 ng/mL and 0.9921 pg/mL, respectively. The practical applicability of proposed strategy was demonstrated by analysis of OTA in spiked corn, soybean and flour samples. This study offers a new insight on multi-mode platforms for various applications. [ABSTRACT FROM AUTHOR]

Volatile species of gold in acidified medium were generated at room temperature by the reduction of NaBH4 using a flow injection vapor generation (FI-VG) system, and trapped in situ on the graphite furnace inner wall to get ETAAS detection. Reaction coil inner-wall and inside of the gas–liquid separator were conditioned by passing through a liquid containing micro amounts of Pd(II) and sodium diethyldithiocarbamate (DDTC) and NaBH4. The FI manifold design, the precondition of the FI-VG system and the effect of temperature parameters for ETAAS are discussed. Optimization of the FI and chemical parameters, such as effect of sample acidity, effect of sodium tetrahydroborate concentration, effects of the flow rates for sample, reagent and carrier gas, effects of HCl and DDTC concentration in rinsing solution were investigated. A detection limit of 0.8 ng/ml (3σ) was obtained with a 40 s trapping time and a sampling frequency of 50/h. The precision of 2.2% R.S.D. (n=11) was obtained at 50 ng/ml level. The method was used for the determination of gold in ore sample digest solution. The recoveries of gold in ore sample digest dilute solution by spiking of 25 ng/ml gold were 90–106%. The results obtained were in good agreement with those obtained from direct ETAAS. [Copyright &y& Elsevier]

Sensitive and reliable analytical methods for monitoring of microcystin-LR (MC-LR) are urgently necessary due to its great harm to human health and aquatic organisms. In this work, a novel Cu/Au/Pt trimetallic nanoparticles (Cu/Au/Pt TNs)-encapsulated DNA hydrogel was prepared for colorimetric detection of MC-LR. The Cu/Au/Pt TNs were captured and released with precise control by the target-responsive 3D DNA hydrogels, which combined dual advantages of the target responsive DNA hydrogel and Cu/Au/Pt TNs of enhanced peroxidase-like activity. The DNA hydrogel network was constructed by hybridizing MC-LR aptamer with two complementary DNA strands on linear polyacrylamide chains. As long as MC-LR presented, the aptamer competitively binds with the MC-LR, causing the hydrogel to dissolve and release the preloaded Cu/Au/Pt TNs which could catalyze the reaction between H 2 O 2 and TMB to produce color changes. In view of this sensitive strategy, this Cu/Au/Pt TNs-encapsulated DNA hydrogel-based colorimetric biosensor can achieve quantitative determination of MC-LR. The results showed that as-proposed colorimetric biosensor could sensitively detect MC-LR with a linear range of 4.0–10000 ng L−1 and a detection limit of 3.0 ng L−1. This work proved that the sensor had great potential to be applied in MC-LR detection and also provided the opportunity to develop colorimetric biosensor for other targets using this target-responsive and signal-amplification strategy. Image 1 • A novel Cu/Au/Pt TNs-encapsulated DNA hydrogel with target-responsive and signal-amplification was prepared. • A colorimetric platform based on this DNA hydrogel was established for sensitive detection of MC-LR. • The colorimetric platform can detect MC-LR with a detection limit to 3.0 ng L−1. • This strategy can be applied to other targets by designing complementary strands of relative aptamer. [ABSTRACT FROM AUTHOR]

Fumonisin (FB) is a common mycotoxin in corn, wheat, oats, and their related products. FB1 is the most predominant among fumonisins and is responsible for severe food contamination that may have deleterious effects on public health. Therefore, the demand for achieving sensitive detection of FB1 is becoming more and more pressing. In the present study, a creative biosensor for FB1 detection was developed based on fluorescence resonance energy transfer between upconversion nanoparticles (UCNPs) and graphene oxide (GO) with catalytic hairpin assembly (CHA) target recycling and amplification. In the presence of FB1, UCNPs were bound to the CHA amplification products away from the GO surface. Simultaneously, a strong fluorescence signal was produced at 980 nm (near-infrared light). The correlation between the concentration of FB1 and the fluorescence intensity exhibited a high relevance (R2 = 0.9971) ranging from 0.032 to 500 ng mL−1, and the method reached a considerably low limit of detection (0.0121 ng mL−1). It could be applied for the detection of FB1 in corn, oats, and infant supplements. The sensitive detection of FB1 proves the application potential of this method on food safety detection. This biosensor can enable high-throughput fungal toxin detection by allowing the use of various aptamers. When FB1 is present, it bound specifically to aptamer so that cDNA is broken away, triggering CHA amplification and producing a large amount of dsDNAs (H1+H2). Further, these dsDNAs are captured by ssDNA-UCNPs because of the principle of base complementary pairing. There was an emergent result that the UCNPs were detached from the surface of GO, leading to the increased fluorescence signal. [Display omitted] • CHA enhanced the detection sensitivity of UCNPs and reduced the effect of surface self-quenching of UCNPs. • CHA regulated the FRET efficiency between UCNPs and GO, inducing the recovery of the GO quenched fluorescence signal. • The proposed biosensor exhibited high satisfactory specificity for the detection of FB1 in imported food. • High throughput fluorescence detection can be achieved by using different UCNPs, aptamers and CHA cycles. [ABSTRACT FROM AUTHOR]

Molecular imprinting technology was employed to produce one kind of malachite green (MG) molecularly imprinted polymers by precipitation polymerization using MG, methacrylic acid, ethylene glycol dimethacrylate, azobisisobutyronitrile, and acetonitrile as template, functional monomer, cross-linker, initiator and porogen, respectively. The binding properties of MG on imprinted polymers were evaluated in acetonitrile by equilibrium rebinding experiments. Scatchard plot''s analysis revealed that there was one class of binding sites populated in the imprinted polymers with an apparent maximum number of MG (2.33μmol/g). The specificity and selectivity of the imprinted polymers were investigated by binding analysis using MG and structurally related compounds. The results indicated that the imprinted polymers showed a good selectivity and specificity for MG. So the polymers can be used to separate MG from seafood, water and other matrices. [Copyright &y& Elsevier]

• Smartphone-based colorimetric/photothermal dual-readout method was studied. • Black phosphorus was first employed as colorimetric/photothermal reagents. • Two orders of magnitude increases in sensitivity. • Low cost and portable method is valuable for on-site detection. A rapid and ultrasensitive method for colourimetric/photothermal dual-readout detection was developed using an 808 nm NIR laser and a thermal imaging app on mobile phone. Norfloxacin was used as a model contaminant to demonstrate this universal rapid detection method. It is innovatively, to use the advanced two-dimensional material black phosphorus as a colourimetric/photothermal reagent for the first time. The samples were added to the strip, and the analytes were selectively captured on the conjugate pad by monoclonal antibody-modified magnetic/upconversion nanocomposites. The samples flowed through the strips by capillary action until reaching the control line, where immune complex formation occurred due to the presence of secondary antibody. The added black phosphorus could be captured by the the antigens which were directly exposed to the test line and a brown band could be observed by naked eye. Upon illumination by NIR light for 1 min, the real-time temperature is obtained for quantitative analysis through the thermal imaging performed by mobile phone camera. This method can achieve the detection of norfloxacin in water samples within 20 min, and the detection limits of colorimetric and photothermal readout can reach 45 pg mL−1. Compared with conventional strips, this method provided an increased sensitivity by about two orders of magnitude, with a integrated portable laser and a mobile phone. It is a valuable method for rapid detection and can be applied to other environmental contaminants as well. [ABSTRACT FROM AUTHOR]

We have recently identified three molecules (tilorone, quinacrine and pyronaridine tetraphosphate) which all demonstrated efficacy in the mouse model of infection with mouse-adapted Ebola virus (EBOV) model of disease and had similar in vitro inhibition of an Ebola pseudovirus (VSV-EBOV-GP), suggesting they interfere with viral entry. Using a machine learning model to predict lysosomotropism these compounds were evaluated for their ability to possess a lysosomotropic mechanism in vitro. We now demonstrate in vitro that pyronaridine tetraphosphate is an inhibitor of Lysotracker accumulation in lysosomes (IC50 = 0.56 μM). Further, we evaluated antiviral synergy between pyronaridine and artesunate (Pyramax®), which are used in combination to treat malaria. Artesunate was not found to have lysosomotropic activity in vitro and the combination effect on EBOV inhibition was shown to be additive. Pyramax® may represent a unique example of the repurposing of a combination product for another disease. • We describe a machine learning model to predict lysosomotropic activity. • We demonstrate that pyronaridine, quinacrine and tilorone all inhibit lysotracker accumulation as predicted. • Artesunate does not appear to inhibit lysostracker accumulation as predicted. • We demonstrate additivity between pyronaridine and artesunate for their in vitro EBOV activity. • These findings suggest pyronaridine and artesunate may be combined and repurposed against EBOV. [ABSTRACT FROM AUTHOR]

The recent outbreaks of the Ebola virus (EBOV) in Africa have brought global visibility to the shortage of available therapeutic options to treat patients infected with this or closely related viruses. We have recently computationally identified three molecules which have all demonstrated statistically significant efficacy in the mouse model of infection with mouse adapted Ebola virus (ma-EBOV). One of these molecules is the antimalarial pyronaridine tetraphosphate (IC 50 range of 0.82–1.30 μM against three strains of EBOV and IC 50 range of 1.01–2.72 μM against two strains of Marburg virus (MARV)) which is an approved drug in the European Union and used in combination with artesunate. To date, no small molecule drugs have shown statistically significant efficacy in the guinea pig model of EBOV infection. Pharmacokinetics and range-finding studies in guinea pigs directed us to a single 300 mg/kg or 600 mg/kg oral dose of pyronaridine 1hr after infection. Pyronaridine resulted in statistically significant survival of 40% at 300 mg/kg and protected from a lethal challenge with EBOV. In comparison, oral favipiravir (300 mg/kg dosed once a day) had 43.5% survival. All animals in the vehicle treatment group succumbed to disease by study day 12 (100% mortality). The in vitro metabolism and metabolite identification of pyronaridine and another of our EBOV active molecules, tilorone, suggested significant species differences which may account for the efficacy or lack thereof, respectively in guinea pig. In summary, our studies with pyronaridine demonstrates its utility for repurposing as an antiviral against EBOV and MARV. • We demonstrate in vitro activity of the antimalarial pyronaridine against multiple strains of Ebola and Marburg. • We describe pharmacokinetics (PK) and range-finding studies in guinea pigs for pyronaridine. • We demonstrate pyronaridine (300 mg/kg) has statistically significant survival in guinea pig infected with Ebola. • In vitro metabolism of pyronaridine in microsomes suggests significant species differences. • These findings also may be useful for repurposing pyronaridine against other viruses in future. [ABSTRACT FROM AUTHOR]