Borax powder

Harnessing dandy mechanical property, hydrogels facilitate the construction of wearable fluorescence sensors for minimally-invasive monitoring pesticide residue in living crops, while the interface self-adaptability and detection accuracy remain hugely challenging. Herein, blue-emission aggregation-induced emission nanoparticles (b-TPE NPs) and red-emission Mn-doped ZnS quantum dots (r-Mn@ZnS QDs) are encapsulated inside agarose, borax, and polyvinyl alcohol-co-constituted hydrogel to construct dual-color TPE@Mn@ZnS@AG@PVA as wearable crop sensor. Owing to specific recognition of r-Mn@ZnS QDs by thiophannate-methyl (TM), the customized TPE@Mn@ZnS@AG@PVA shows a gradual color evolution from reddish purple to blue with high resistance to environmental and experimental interferences via quenching r-Mn@ZnS QDs' fluorescence by target-induced aggregation and photo-induced electron transfer while acting negligible disturbance in blue fluorescence of b-TPE NPs, consequently achieving TM dual-color assay with limit of detection at 0.045 µg mL-1. Additionally, TPE@Mn@ZnS@AG@PVA fascinates smart interface self-adaptability, high adhesion, and outstanding self-repairing function, and then is pasted onto the interfaces of crops to deliver on the sense pesticide residue data in minimally-invasive manner, leading to the monitor of dynamic TM degradation. This study offers an in-depth penetration into dual-color wearable sensor with distinctive features for minimally-invasive monitoring pesticide residue in living crops, advancing the development of wearable crop sensors and precision agriculture.

Abstract licence: CC BY

Chronic wound healing is a significant challenge in diabetes. Puerarin is an active compound extracted from the traditional Chinese medicine Pueraria lobata. Puerarin has been used in the treatment of diabetes and derives benefits from its antioxidant, anti-inflammatory, antibacterial, and pro-angiogenesis properties, but its efficacy is hampered by poor water solubility and bioavailability. In this study, we designed a polyvinyl alcohol (PVA)-borax-puerarin (BP) hydrogel system that self-assembled via boronic ester bonds. The BP hydrogel exhibited exceptional physical characteristics, including adaptability, injectability, plasticity, self-healing capabilities, and robust compressive strength, as well as good biocompatibility. In the chronic wound diabetic rats model, the BP hydrogel significantly accelerated wound healing, as evidenced by hematoxylin and eosin (HE) staining, as well as Masson and picrosirius red (PSR) staining. RNA-sequencing and multiple immunohistochemistry (mIHC) analyses revealed that the BP hydrogel exerts a therapeutic effect by modulating macrophage polarization, promoting angiogenesis, and regulating collagen remodeling. Our findings suggest that the BP hydrogel represents a promising wound dressing and holds great potential for clinical applications in acute and chronic wound management.

Abstract licence: CC BY

Self-healing hydrogels have the ability to repair themselves at the incision after being damaged and can return to their original state of morphology and performance. However, constructing a hydrogel with superior mechanical strength and tensile properties after self-healing remains a challenge. In this work, using polyvinyl alcohol, borax, chitosan, and a type of SiO2@g-C3N4@TiO2 nanoparticles as raw materials, a novel photo-regulated self-healing hydrogel was developed using a freezing-thawing method, which could achieve a synchronous increase in Young's modulus and tensile strength under visible light irradiation during the self-healing process. In addition, the doping of the SiO2@g-C3N4@TiO2 nanoparticles improved the self-healing performance of the PVA-based hydrogels. With the addition of a trace amount of SiO2@g-C3N4@TiO2 nanoparticles, the self-healing efficiency of the hydrogel increased from 26.67% to 45.67% in darkness and from 41.33% to 65.67% under visible light irradiation.

Abstract licence: CC BY

Polysaccharide-based hydrogels have been utilized as flexible strain sensors because of their renewability, biocompatibility, and biodegradability. However, their widespread application is hindered by the complexity of their manufacturing processes and the inevitable degradation of their mechanical properties with repeated use. The introduction of reversible bond chemistry offers the potential to impart self-healing properties to hydrogels, extending their functional lifespan. In this study, we prepared a starch-based conductive hydrogel (starch/poly(vinyl alcohol) (PVA)/cellulose nanocrystals (CNCs)) via a straightforward method using borax as a cross-linking agent. The hydrogel demonstrated improved strength and self-healing property because of the addition of CNCs, which formed dual reversible cross-links with starch and PVA via hydrogen and borate ester bonds. Additionally, the sodium ions (Na+) and borate ions (B(OH)4-) within the network enhanced the electrical conductivity and strain sensitivity of the hydrogel. The resulting hydrogel demonstrated potential for application as a wearable sensor capable of monitoring a range of human movements, sensing handwriting, and enabling Morse code communication. Notably, the hydrogel could be easily remolded at room temperature after being sectioned, highlighting its practical applicability. This work expands the scope of the use of starch-based hydrogels in sustainable wearable sensor technologies.

Abstract licence: CC BY

Wearable sensors for continuous physiological monitoring during intense exercise face significant challenges, including motion artifacts and skin discomfort. Conductive hydrogels offer a promising solution due to their skin-like flexibility and excellent electrical conductivity, yet their application in extreme conditions like marathon running remains challenges. Here, we develop a MXene-based dual-network hydrogel composed of polyvinyl alcohol (PVA) and tempo-oxidized cellulose nanofibers (TOCNF) crosslinked with MXene nanosheets and borax. This hydrogel exhibits exceptional environmental stability (35 days at 4 °C and 30% relative humidity) and strain sensitivity (gauge factor of 7.79 at 800% strain), while MXene integration provides outstanding antibacterial properties (>99% inhibition). As a proof of concept, under simulated marathon conditions (38°C, 52% relative humidity), the sensor maintains stable performance for 6 h, demonstrating reliable heart rate and respiration monitoring. These capabilities are crucial for identifying early signs of cardiorespiratory abnormalities during endurance sports. Our work presents a robust strategy for developing wearable hydrogel sensors with long-term reliability in extreme environments, offering significant potential for sports medicine, exercise physiology, and continuous health monitoring applications.

Abstract licence: CC BY-NC-ND

The black fig fly, Silba adipata (Diptera: Lonchaeidae), is an invasive pest recently introduced to Mexico, where it has rapidly spread across fig-producing regions. Despite its economic importance, effective monitoring strategies remain poorly studied. The present study evaluated the response of S. adipata adults to visual (color) and olfactory (attractant) cues under laboratory and field conditions in fig orchards. No significant color preferences were observed in laboratory choice tests using nine colors or in field trials using traps of four different colors. In the laboratory, traps containing 2% ammonium sulfate solution, torula yeast + borax, or Captor + borax, captured similar numbers of flies, whereas CeraTrap® was less attractive. Traps containing 2% ammonium sulfate were more effective than 2% ammonium acetate, though attraction was comparable when ammonium acetate was diluted to 0.2% or 0.02%. In the field, torula yeast + borax and 2% ammonium sulfate mixed with fig latex outperformed the 2% ammonium sulfate solution alone, although seasonal variation influenced trap performance. A high proportion of field-captured females were sexually immature. Torula yeast + borax attracted high numbers of non-target insects and other lonchaeid species, which reduced its specificity. In contrast, traps containing fig latex mixtures showed higher selectivity, although some S. adipata adults could not be sexed due to specimen degradation. These findings highlight the value of torula yeast pellets and 2% ammonium sulfate plus fig latex for monitoring this pest, but merit validation in field studies performed over the entire crop cycle across both wet and dry seasons. Future studies should evaluate other proteins, ammonium salt combinations and fig latex volatiles in order to develop effective and selective monitoring or mass trapping tools targeted at this invasive pest.

Abstract licence: CC BY