When the in vitro research works of biosensing begin to mimic in vivo conditions, some certain three-dimensional (3D) structures of biosensors are needed to accommodate biomolecules, bacteria or even ...cells to resemble the in vivo 3D environment. To meet this end, a novel method of synthesizing CuO nanoflowers on the 3D graphene foam (GF) was first demonstrated. The 3DGF/CuO nanoflowers composite was used as a monolithic free-standing 3D biosensor for electrochemical detection of ascorbic acid (AA). The 3D conductive structure of the GF is favorable for current collection, mass transport and loading bioactive chemicals. And CuO nanoflowers further increase the active surface area and catalyze the redox of AA. Thus, all these features endows 3DGF/CuO composite with outstanding biosensing properties such as an ultrahigh sensitivity of 2.06mAmM−1cm−2 to AA at 3s response time.
•The synthesis of 3D graphene foam (GF)/CuO nanoflowers composite was proposed.•The 3DGF provides vast area and a well-organized conducting freestanding network.•CuO nanoflowers maximize the surface area, transfer electrons between 3DGF and AA.•3DGF/CuO has an ultrahigh sensitivity of 2.06mAmM−1cm−2 to AA.•3DGF/CuO could be a smart sensing platform to support cells and detect analytes.
Numerous astrophysical observations strongly suggest the existence of Dark Matter, which provides a hint of dark sector physics. There could exist many dark candidates predicted by theories BSM, such ...as dark photons and invisible things, that communicate with the Standard Model sector. The masses and decay modes of these particles are expected to be accessible at the BESIII experiment which is the only currently running tau-charm factory with the largest threshold charm samples and some other unique datasets. We have recently performed searches of dark photons and invisible things in several decay modes. Besides, FCNC processes, BNV/LNV processes are also investigated. This talk will summarize the recent results at BESIII on these searches for new physics BSM.
Copper ion (Cu2+) pollution poses a serious threat to marine ecology and fisheries. However, the complexity of seawater and its interference factors make the online detection of Cu2+ quite ...challenging. To address this issue, we introduce the concept of the photo-assisted adjustment barrier effect into electrochemical detection, using it as a driving force to generate electrochemical responses. The Schottky barrier demonstrates a remarkable regulatory influence on the electrochemical response under photoexcitation, facilitating the response through Cu2+ adsorption. We developed a 4-MBA-AuNPs/CdS/FTO composite that serves as a sensitive platform for Cu2+ detection, achieving a detection limit of 70 nM. Notably, the photo-assisted adjustment of the barrier effect effectively counters the interference posed by ions in seawater, ensuring accurate detection. Furthermore, the sensor exhibits a promising recovery rate (99.62–104.9%) in real seawater samples, highlighting its practical applications. This innovative approach utilizing the photo-assisted adjustment barrier effect offers a promising path for developing electrochemical sensors that can withstand interference.
A new sample introduction method of nebulized film dielectric barrier discharge (NFDBD) assisted chelate vapor generation coupled with inductively coupled plasma mass spectrometry (ICP-MS) for trace ...rare earth elements (REEs) determination in environmental water was developed in this work. Using 2,2,6,6-tetramethyl-3,5-heptanedione (DPM) as chelating reagent, the volatile and stable chelates of REE-DPM were effectively vaporized in NFDBD sampling system, leading to 8–9 folds enhancement of REEs sensitivity compared with solution nebulization sampling system, with the sample introduction efficiencies between 51.9% and 66.0%. The enhancement mechanism and the experimental parameters for REEs determination including the DPM concentration, the carrier solution concentration, the input discharge voltage and the argon flow rate were evaluated in detail. The interferences from sample matrix at 10 mg L−1 level and the degradation product of DPM at 0.5 mmol L−1 were also found negligible for trace REEs determination in NFDBD sampling system. Under optimized conditions, the relative standard deviations for 15 REEs were between 0.3% and 2.5% at the concentration of 0.5 μg L−1 and the detection limits for 15 REEs were between 0.0009 and 0.11 ng L−1, which were 1–2 orders of magnitude lower than other sampling systems such as solution nebulization, membrane desolvation, ultrasonic nebulization and electrothermal vaporization and 2–4 folds lower than NFDBD vapor generation system without chelate. This proposed method not only can be used for trace REEs determination directly in freshwater samples, but also is promising for seawater determination without column separation.
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•NFDBD assisted chelate vapor generation with ICP-MS for REEs analysis was developed.•The REEs sampling efficiency by NFDBD was highly improved with the chelate of DPM.•The LOD of REEs was much lower than other sampling systems such as USN, ETV, etc.•This method can be used for REEs analysis directly in water at sub ng L−1 level.
The sensitive online detection technique for heavy metal ions present in ocean, while effectively eliminating the interference of other chemicals, has been lacking at the present time. We found that ...the interfacial barrier of ZnO/rGO/PPy heterostructure had powerful physical effects on electrochemistry, and the Schottky barrier driven electrochemical detection was further developed. As based on the interfacial physical barrier, it could avoid the existing problem of the traditional electrochemical sensing mechanism and apply in more interfering environment. The sensitive detection of trace mercury ion (Hg2+) in actual seawater was achieved by employing the ZnO/rGO/PPy heterostructure. The interfacial barrier effect provides a chance to develop sensors used in more interfering environment.
•The interfacial barrier of ZnO/rGO/PPy heterostructure had powerful physical effects on electrochemistry.•The interfacial barrier driven electrochemical detection was developed.•The sensitive detection of trace Hg2+ in actual seawater was achieved.
In this work, a novel and sensitive procedure for Cr determination by inductively coupled plasma mass spectrometry (ICP-MS) with a chelate-enhanced nebulized film dielectric barrier discharge (NFDBD) ...vapor generation sampling system was developed. Using sodium diethyldithiocarbamate (DDTC) as a chelating reagent, the sensitivity of Cr(
vi
) was specifically increased 10.5-fold by the DDTC-enhanced NFDBD sampling system compared with pneumatic nebulization. The enhancement mechanism and the experimental parameters for Cr(
vi
) determination such as the DDTC concentration, the solution pH, the input discharge voltage and the argon (DBD plasma gas) flow rate were evaluated in detail. The interferences from the sample matrix at 10-100 mg L
−1
level were found negligible for trace Cr(
vi
) determination in the NFDBD sampling system. Under optimized conditions, the relative standard deviation for Cr(
vi
) was 1.4% at the concentration of 5 μg L
−1
and the detection limit for Cr(
vi
) was 0.023 μg L
−1
. After oxidation of the Cr species to Cr(
vi
), the total Cr in environmental and biological samples could be sensitively determined by this DDTC-enhanced NFDBD-ICP-MS system. The determined values of the total Cr (29.8 ± 0.3 ng g
−1
and 402.8 ± 18.8 ng g
−1
) in the standard reference materials of the simulated natural water sample (GBW08608) and biological tissue sample (GBW10210) agreed well with the certified values (30 ± 2 ng g
−1
and 0.4 ± 0.08 μg g
−1
), respectively. It is also worth noting that this is the first report to use DBD induced vapor generation of Cr. Compared with other sampling techniques such as chemical vapor generation and electrothermal vaporization, this proposed technique has a competitive detection limit for trace Cr determination. Furthermore, it eliminates the additional reducing agent for vapor generation, and could operate with low cost and low power (≤65 W).
A sensitive procedure was developed for trace Cr determination by ICP MS with a DDTC enhanced nebulized film dielectric barrier discharge (NFDBD) vapor generation sampling system.
Nanozymes possess major advantages in catalysis and biosensing compared with natural nanozymes. In this study, the AuPt@BaTiO3 bimetallic alloy Schottky junction is prepared to act as oxidase ...mimetics, and its photo−piezoelectric effect is investigated. The synergy between the photo−piezoelectric effect and the local surface plasmon resonance enhances the directional migration and separation of photogenerated electrons, as well as hot electrons induced by the AuPt bimetallic alloy. This synergy significantly improves the oxidase−like activity. A GSH colorimetric detection platform is developed based on this fading principle. Leveraging the photo−piezoelectric effect allows for highly sensitive detection with a low detection limit (0.225 μM) and reduces the detection time from 10 min to 3 min. The high recovery rate (ranging from 99.91% to 101.8%) in actual serum detection suggests promising potential for practical applications. The development of bimetallic alloy heterojunctions presents new opportunities for creating efficient nanozymes.
We provide a facile, cost-effective and environmentally friendly method to prepare 3D hierarchical porous Co3O4 film by employing eggshell membrane as bio-templates. The Co3O4 nanofibers ...interconnected with each other to construct a 3D hierarchical porous film with macropores and mesopores, which is more effective in facilitating reactants diffusion and the electron transfer. The developed sensor was applied for direct electrochemical non-enzymatic detection of glucose. High sensitivity (366.03μAmM−1cm−2), fast response (3s), anti-interference performance and excellent stability were achieved. The results demonstrate that the 3D hierarchical porous Co3O4 film have great potential applications in developing direct electrochemical non-enzymatic glucose biosensors.
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•The 3D hierarchical porous Co3O4 film was prepared by employing eggshell membrane as bio-templates.•The 3D hierarchical film is more effective in facilitating reactants diffusion and the electron transfer.•The Co3O4-based sensor was applied for direct electrochemical non-enzymatic detection of glucose.•It shows high sensitivity (366.03 μAmM−1cm−2), fast response (3s), excellent stability and anti-interference performance.
The 3D Ni/NiO/MoO3/chitosan foam was fabricated and the interfacial barrier of p-n junction was proposed as a driving factor for electrochemical detection of Cu2+. The electrochemical response ...resulted from the decreased barrier height caused by the absorbed Cu2+. The liner range (0–25 μM) and the lower detection limit (5.69 nM) were obtained. The direct electrochemical detection of Cu2+ in real water sample with excellent stability and recovery was achieved. It affords a new approach to achieve the direct electrochemical detection of metal ions with depressed interference by employing the interfacial effects of p-n junction.
•A novel strategy of using the p-n interfacial barrier for Cu2+ detection was proposed.•The direct detection of Cu2+ in real water sample with excellent recovery was achieved.•The low detection limit (5.69 nM) were obtained.
•A 3D chitosan/carbon nanotubes aerogel was synthesized by an ice-template method.•The snubby carbon nanotubes tips emerged on the surface of the soft chitosan nanosheets.•The unique surface ...structure brought novel properties and got multifunctional biosensing applications.•In situ adsorbed growth of chipped core-shell nanostructures, effective non-enzymatic biosensors were achieved.
A novel 3D chitosan/multiwalled carbon nanotubes (CNTs) aerogel with snubby CNTs tips emerged on the surface of soft nanosheets was synthesized by ice-templating method. The ideal cooperative effect of phragmoid CS and electrical CNTs offered synthetical properties, such as low density (about 6.3mgcm−3), flexibility, absorption, catalysis capacities, improved electrochemical characteristics and novel applications. This unique architecture showed good specificity to dopamine with ultralow detection limit of 0.3nM in biosensing applications. Meanwhile, the unique surface of soft nanosheets with snubby CNTs tips makes it an incubative bed for in situ adsorbed growth of nanostructures. Cu2O@CuO chipped core-shell nanoparticles were in situ grown onto the soft nanosheets by simple adsorption of Cu2+ and used for non-enzymatic detection.
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