Droplet directional transportation plays a crucial role in many fields such as microfluidics, device thermal management, and water harvesting. Gradient wetting is an important approach to drive droplets by establishing a patterned surface energy distribution. However, existing chemical or physical gradient methods suffer from limitations such as contamination, irreversibility, and insufficient reconfigurability, making it difficult to achieve stable and dynamic manipulation. In this work, we propose an opto-electrical gradient wetting system on a crystal silicon (OE-GWOS) device for programmable droplet manipulation. By applying patterns with a grayscale gradient, the resistivity of crystal silicon is spatially and continuously modulated, inducing continuous variation in voltage distribution across the dielectric layer, thereby constructing a reconfigurable wetting gradient on the surface for stable and continuous droplet driving. Moreover, the gradient can be dynamically reconstructed along arbitrary directions and at arbitrary locations on the chip, enabling flexible and programmable droplet operations. Compared to discrete light spot driving, this strategy significantly improves motion continuity and stability, reduces system control complexity, and supports complex manipulations, including multidirectional motion and path planning with no need for real-time addressing. It provides a new route toward highly reliable, reconfigurable, and programmable digital microfluidics with potential for integration with microelectronics.
Ferroptosis is a newly discovered type of cell death, which is distinct from apoptosis and autophagy. Extensive efforts verified that ferroptosis is a key factor in the process of drug-induced liver injury (DILI). As such, inventing a dependable method for assessing the involvement of ferroptosis in DILI is of great significance. Therefore, we designed a novel Golgi apparatus-targetable fluorescence probe (Golgi-V) for detecting viscosity in ferroptosis-driven drug-induced liver injury, which was prepared by linking a phenylsulfonamide moiety to a conjugated hemicyanine derivate. In vitro environment, this probe was only sensitive to viscosity changes, rather than to polarity or other reactive molecules. Moreover, in the cell confocal fluorescence imaging experiments, the probe precisely concentrated within the Golgi apparatus, enabling the imaging of viscosity alterations during ferroptosis. Notably, employing the probe, the viscosity variations were favourably detected in ferroptosis-driven DILI. Therefore, targeted regulation of the ferroptosis pathway conduced to alleviate the symptoms of DILI, providing a highly prospective strategy for the treatment of liver disease.
Magnetically actuated droplets offer a remote, low-resistance route for microscale sample handling in chemical analysis, biomedical testing, and environmental monitoring. Yet practical applications require droplets not only to move reliably, but also to deform for reagent access and analysis while remaining protected from external contamination, which remains difficult when traditional magnetic methods are largely limited to movement control. Here, we report a reconfigurable magnetorheological armor in which magnetic colloids assemble into an external armor layer at the droplet interface. Under magnetic fields, the colloids form chain-like networks that reinforce the interfacial armor, transmit magnetic force, and keep the liquid core additive-free. By tuning field geometry, the armor redistributes across the droplet surface, enabling programmable deformation, on-demand detachment, low-resistance transport, and robust operation on contaminated surfaces, vertical substrates, immiscible liquids, and confined tubing. This field-regulated interface achieved a deformation recovery rate above 97.5%, a motion resistance as low as 0.164 mN, and droplet velocities up to 14.5mm/s. In a Cu2+ colorimetric assay, armored droplets underwent protected cross-media transfer, local opening, reagent coalescence, and re-encapsulation, achieving 99.3% colorimetric accuracy. This work turns the droplet surface into a field-programmable interface for actuation, protection, and on-demand analysis.
In this study, a novel bioelectronic sensor (BES) was rationally designed based on SnS2 nanosheets (NSs) and hybridization chain reaction (HCR), which synergistically amplifies the signal for ultrasensitive miRNA-145 detection. At the biocathode, SnS2 NSs exhibit excellent electrical conductivity and outstanding bilirubin oxidase (BOD)-like activity to promote the catalytic reduction of O2 to generate H2O via a four-electron process. At the bioanode, HCR was employed to amplify the output of signal-DNA with glucose oxidase (GOD) to facilitate the catalytic oxidation of glucose. When miRNA-145 is present, it recognizes and binds with the hairpin cDNA on cDNA/Au NPs/SnS2 NSs@CP. After adding hairpins H1 and H2, miRNA-145 triggers the conformational opening of hairpin H1, thereby initiating the HCR. In the HCR process, GOD is conjugated with hairpins H1 and H2, respectively. After the assembly of H1-GOD and H2-GOD, more GOD molecules are bound to the bioanode surface to catalyze the oxidation of glucose, generating electrons to drive the BES, ultimately achieving a significant enhancement of the open-circuit voltage (EOCV). In addition, a capacitor was introduced to store charges for further amplifying the transient current, and the BES with a capacitor exhibited a 7.24-fold improvement in sensitivity for miRNA-145 assay. A smartphone was also integrated for visual miRNA-145 assay. The BES ultimately achieves ultra-sensitive detection of miRNA-145 with a limit of detection (LOD) as low as 0.0107 fM and a linear detection range of 0.1 ~ 105 fM. Moreover, the BES exhibits high selectivity, excellent stability, and good specificity, as well as applicability in spiked human serum testing.
Reliable acetone detection at very low concentrations remains challenging, necessitating the development of novel gas-sensing materials. Amorphous high-entropy metal oxides combine the long-range disordered and short-range ordered characteristics of amorphous materials with the compositional complexity and possible multicomponent synergistic effects of high-entropy systems, making them promising candidates for gas sensing. However, relevant reports remain scarce. In this work, for the first time, we synthesize cubic-block-shaped amorphous-phase (Cu0.2Ni0.2Zn0.2Co0.2Cd0.2)SnO3 high-entropy metal oxide MSnO3 materials via a facile and low-cost hydrothermal method. The results demonstrate that at 250 °C, the sensor obtains a response value of 6.78 towards 100 ppm acetone, exhibits reproducible sensing at the lowest experimentally tested nominal concentration of 25 ppb, and has response/recovery times of 1.5s and 118s, respectively. Furthermore, the sensor exhibits excellent selectivity for acetone, with a response value at least 2.11 times higher than that for other tested gases. The superior gas-sensing performance may be associated with the amorphous interfacial structure, multicomponent synergistic effects, and local structural disorder. This study provides a new strategy for the design and development of high-performance acetone gas-sensing materials.
