Constructed on the moiety of a lactam screw ring, a near-infrared fluorescent probe RCya for Pd2+ was designed under the PET mechanism and synthesized by incorporating 2,4-dihydroxybenzaldehyde as ...the recognition group. Dynamic detection of aqueous Pd2+ by the probe RCya could be accomplished through ion competition, linear response, fluorescence-pH/time stabilities, and other optical tests. Moreover, the high selectivity, low cytotoxicity, cell permeability, and lysosome accumulation properties of RCya enabled the imaging applications on solid-state RCya–PAN composite nanofibers and in living cells. The recognition mechanism of probe RCya toward Pd2+ was further studied through simulation calculation and MS analysis.
Novel spherical polymer nanoparticles were synthesized by hyperbranched polyethylenimine (hPEI) and 6-hydroxy-2-naphthaldehyde (HNA) via Schiff base reaction (one-pot reaction), which had great ...advantages in water solubility and green synthesis. Meanwhile, probe PEI-HNA could quickly detect Cu
2+
in the range of 0–60 μM in 30 s with the detection limit of 243 nM. The fluorescence of PEI-HNA-Cu
2+
could be recovered by the addition of S
2−
in 50 s with the detection limit of 227 nM. Based on the excellent optical properties, PEI-HNA has been used in the bioimaging of living cells with excellent cell penetrability and low toxicity. More importantly, PEI-HNA has been doped into filter paper, hydrogel, and nanofibrous film to prepare solid-phase sensors, displaying rapid response and excellent sensitivity. Moreover, the low-cost and simple preparation of these sensors offers great potential and possibilities for industrialization, which could help accelerate the development of sensors in environmental and biological fields.
Constructed on the benzothiazole-oxanthracene structure, a fluorescent probe RBg for Cu
was designed under the ESIPT mechanism and synthesized by incorporating amide bonds as the connecting group and ...glyoxal as the identifying group. Optical properties revealed a good sensitivity and a good linear relationship of the probe RBg with Cu
in the concentration range of Cu
= 0-5.0 μmol L
. Ion competition and fluorescence-pH/time stability experiments offered further possibilities for dynamic Cu
detection in an aqueous environment. HRMS analysis revealed a possible 1:1 combination of RBg and Cu
. In addition, colorimetric Cu
detection and lysosome-targeted properties of the probe RBg were analyzed through RBg-doped PVDF nanofiber/test strips and RBg-Mito/Lyso trackers that were co-stained in living HeLa cells, enabling the probe's future applications as real-time detection methods for dynamic Cu
tracking in the lysosomes and Cu
detection under diversified conditions.
Glutathione and 2-aminopyridine are used as carbon sources to prepare carbon dots (CDs) by a one-step hydrothermal reaction. The results show that the average particle diameter of CDs is 8.64 nm with ...uniform size distribution and the fluorescence quantum yield is 13.62%. We further demonstrate that novel CDs possess highly selective sensing of Fe
3+
from 0.2 to 200 μM with a low detection limit (0.194 μM). Meanwhile, the fluorescence of CDs can be repeated many times by the addition of S
2−
. Moreover, the CDs are used for biological imaging of living cells with well cell penetrability and low toxicity. Furthermore, it is successfully applied for anti-counterfeiting and information encryption. More interestingly, it can be doped with hydrogel and filter paper to prepare solid-phase sensors exhibiting high sensitivity and fast response, demonstrating their tremendous potential for the simple, rapid, and low-cost monitoring of Fe
3+
and S
2−
.
Graphical abstract
Predicting the aggregation tendency of nanoscale zero-valent iron (nZVI), oxidized nZVI, in particular, is crucial for the risk assessment of nZVI in aquatic environments. In this study, the ...comprehensive effects of the pH and ionic strength (IS) on the aggregation behaviors of two highly oxidized nZVIs (HO-nZVI) were examined. Compared with hematite nanoparticles, HO-nZVI presented a sudden acceleration in aggregation under critical conditions; moreover, the morphology of the HO-nZVI aggregates at pH and IS values higher or lower than the critical conditions was significantly different. Furthermore, owing to the differences in magnetization between the two prepared HO-nZVI samples, their critical coagulation conditions were significantly different. The significant changes in the aggregation behavior of the HO-nZVI samples were analyzed using colloidal theories, and the aggregation tendency of HO-nZVI under specific conditions could be simulated by calculating the theoretical critical conditions of aggregation via a method that takes into account the hydrochemical properties, magnetization, and surface charge of HO-nZVI. To examine the correctness of the method, we compared the experimentally determined colloidal stability of HO-nZVI in water samples collected from nearby rivers with the theoretically predicted value. The results indicated that the method was adequate for most situations, except for those in which the hydrochemical properties of the water samples were close to the critical coagulation conditions. Our study proposes a theoretical approach that is viable for simulating the colloidal stability of magnetic nanoparticles in aquatic environments; we anticipate that it will further facilitate the risk assessment of nanoparticles.
A simple naphthofluorescein-based probe was designed and synthesized by a two-step method. As expected, there was a good linear relationship between fluorescence intensity (680 nm)/absorbance ...(640 nm) and H2S concentration in the range of 2.00–10.0 μM with a detection limit of 0.50 μM/0.10 μM (S/N = 3). This probe was applied to monitor H2S concentration in red wine samples. Furthermore, it was successfully used to image exogenous H2S in living Hela cells, indicating its potential application in biology and medicine.
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•A simple naphthofluorescein-based probe was designed and synthesized by a two-step method.•The probe exhibited high sensitivity, high selectivity, rapid response for H2S.•The probe was employed in red wine analysis with satisfactory results.•It was successfully used to monitor and image H2S in Hela cells.
Hierarchically porous carbonaceous sponges and their magnetic nanocomposites were fabricated by a combined approach of hydrothermal carbonization and freeze drying. The resulting carbonaceous sponges ...have hierarchically porous structure and a large number of oxygen-containing functional groups. The unique structure enables carbonaceous sponges candidate materials for rapid and efficient organic molecules removal from water.
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•The CS is sustainable, inexpensive and hierarchically porous.•The CS exhibits excellent adsorption capacities toward organic molecules.•Convenient solid–liquid separation after removal of organic molecules is achieved by introducing Fe3O4 NPs into CS network.
This work describes the preparation, characterization and removal capability of a novel biomass derived carbonaceous sponges (CS) and their nanocomposites. The CS has hierarchically porous structure which is composed of lamellar structures and secondary porous structures. The pore size is on a scale from 1nm to 200μm. Utilizing the CS as adsorbents, rapid removal of model organic molecules, including methylene blue (MB), methyl orange (MO) and crystal violet (CV), from their aqueous solutions can be completed within 1min with the assistance of pressure and the removal efficiency reaches up to 100%, 81% and 98%, respectively. The removal capabilities for CS towards MB, MO and CV are 0.0769g/g, 0.2218g/g and 1.0384g/g, respectively and 0.0635g/g, 0.0977g/g and 0.8634g/g, respectively for CS nanocomposites.
Copper is a vital trace metal in human body, which plays the significant roles in amounts of physiological and pathological processes. The application of copper-selective probe has attracted great ...interests from environmental tests to life process research, yet a few of sensitive Cu
2+
tests based on on-site analysis have been reported. In this paper, a novel fluorescein-based fluorescent probe N4 was designed, synthesized, and characterized, which exhibited high selectivity and sensitivity to Cu
2+
comparing with other metal ions in ethanol–water (1/1, v/v) solution. The probe N4 bonded with Cu
2+
to facilitate the ring-opening, and an obvious new band at 525 nm in the fluorescence spectroscopy appeared, which could be used for naked-eye detection of Cu
2+
within a broad pH range of 6–9. Meanwhile, a good linearity between the fluorescence intensity and the concentrations of Cu
2+
ranged 0.1–1.5 eq. was observed, and the limit of detection of N4 to Cu
2+
was calculated to be as low as 1.20 μm. In addition, the interaction mode between N4 and Cu
2+
was found to be 1:1 by the Job's plot and mass experiment. Biological experiments showed that the probe N4 exhibited low biological toxicity and could be applied for Cu
2+
imaging in living cells. The significant color shift associated with the production of the N4-Cu
2+
complex at low micromolar concentrations under UV light endows N4 with a promising probe for field testing of trace Cu
2+
ions.
Flexible electronic devices (FEDs) based on hydrogels are attracting increasing interest, but the fabrication of hydrogels for FEDs with adhesiveness and high robustness in harsh‐temperature ...conditions and long‐term use remains a challenge. Herein, glutinous‐rice‐inspired adhesive organohydrogels are developed by introducing amylopectin into a copolymer network through a “one‐pot” crosslinking procedure in a glycerol–water mixed solvent containing potassium chloride as the conductive ingredient. The organohydrogels exhibit excellent transparency (>90%), conductivity, stretchability, tensile strength, adhesiveness, anti‐freezing property, and moisture retention ability. The wearable strain sensor assembled from the organohydrogels achieves a wide working range, high sensitivity (gauge factor: 8.82), low response time, and excellent reversibility, and properly responds in harsh‐temperature conditions and long‐time storage (90 days). The strain sensor is further integrated with a Bluetooth transmitter and receiver for fabricating wireless wearable sensors. Notably, a sandwich‐structured capacitive pressure sensor with organohydrogels containing reliefs as electrodes records a new gauge factor of 9.43 kPa−1 and achieves a wide response range, low detection limit, and outstanding reversibility. Furthermore, detachable and durable batteries and all‐in‐one supercapacitors are also fabricated utilizing the organohydrogels as electrolytes. Overall, this work offers a strategy to fabricate adhesive organohydrogels for robust FEDs toward wearable sensing, power supply, and energy storage.
Glutinous‐rice‐inspired organohydrogels with integrated adhesiveness, stretchability, transparency, conductivity, anti‐freezing, and moisture retention ability are developed by introducing amylopectin into a copolymer network and employed in flexible electronic devices toward wearable sensing, power supply, and energy storage. High sensitivity (gauge factor: = 8.82) for resistive strain sensors and a new sensitivity record (gauge factor: 9.43 kPa−1)for hydrogel‐based pressure sensors are achieved.
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•Intrinsically adhesive and temperature tolerant flexible sensors are fabricated.•Strain sensor achieves a GF of 2.58 and a sensing range of 0–1000%.•Reliefs on electrodes lead to a ...GF of 2.14 kPa−1 for pressure sensor.•Wireless strain sensor is demonstrated based on a bluetooth protocol.
Hydrogel-based flexible sensors are of promising applications in various fields, but fabrication of such sensors with integrated high performances remains a challenge. In this work, flexible sensors (both strain sensors and pressure sensors) with integrated high performances are fabricated utilizing double network (DN) organohydrogels. Because of the unique structure of DN organohydrogels, the flexible sensors exhibit intrinsic adhesion without introducing components that are often used to obtain adhesive hydrogels, such as polydopamine, nucleobases or proteins. In addition, outstanding temperature tolerance (−18 to 80 °C), high stretchability (>2000%), tensile strength (>300 kPa), self-healing ability (96.5%) and transparency (90%) are also achieved. Resistive-type strain sensors of DN organohydrogels achieve high gauge factor (GF = 2.58), low response time (0.18 s), large sensing range (0–1000%) and reversible sensing ability (>1000 cycles). Sandwich-shaped capacitive-type pressure sensors comprising DN organohydrogel electrodes with reliefs exhibit a high sensitivity of 2.14 kPa−1. Such flexible sensors can be applied in monitoring various human motions and subtle physiological activities and further promoted as wireless sensors on the basis of a Bluetooth protocol.
