Tin (Sn) is known to be a good catalyst for electrochemical reduction of CO2 to formate in 0.5 M KHCO3. But when a thin layer of SnO2 is coated over Cu nanoparticles, the reduction becomes ...Sn-thickness dependent: the thicker (1.8 nm) shell shows Sn-like activity to generate formate whereas the thinner (0.8 nm) shell is selective to the formation of CO with the conversion Faradaic efficiency (FE) reaching 93% at −0.7 V (vs reversible hydrogen electrode (RHE)). Theoretical calculations suggest that the 0.8 nm SnO2 shell likely alloys with trace of Cu, causing the SnO2 lattice to be uniaxially compressed and favors the production of CO over formate. The report demonstrates a new strategy to tune NP catalyst selectivity for the electrochemical reduction of CO2 via the tunable core/shell structure.
The development of versatile nanotheranostic platforms that integrate both diagnostic and therapeutic functions have always been an intractable challenge in precise cancer treatment. Herein, an ...aptamer‐tethered deoxyribonucleic acids‐gold particle (Apt‐DNA‐Au) nanomachine has been developed for in situ imaging and targeted multimodal synergistic therapy of mammary carcinoma. Upon specifically internalized into MCF‐7 cells, the tumor‐related TK1 mRNA activates the Apt‐DNA‐Au nanomachine by DNA strand displacement cascades, resulting in the release of the fluorophore and antisense DNA as well as the aggregation of AuNPs for in situ imaging, suppression of survivin expression and photothermal therapy, respectively. Meanwhile, the controlled released drugs are used for chemotherapy, while under the laser irradiation the loaded photosensitizer produces reactive oxygen species (ROS) for photodynamic therapy. The results confirm that the proposed Apt‐DNA‐Au nanomachine provides a powerful nanotheranostic platform for in situ imaging‐guided combinatorial anticancer therapy.
A multifunctional DNA‐Au nanomachine which can be triggered by endogenous tumor growth‐related TK1 mRNA has been devised as the combinatorial theranostic agent for fluorescence imaging‐guided chemo, genic, photodynamic, and photothermal synergistic targeted therapy of breast cancer. This theranostic nanoplatform achieves the significant inhibition of tumor growth and improvement of therapeutic efficacy through in situ imaging.
To obtain graphene-based fluorescent materials, one of the effective approaches is to convert one-dimensional (1D) graphene to 0D graphene quantum dots (GQDs), yielding an emerging nanolight with ...extraordinary properties due to their remarkable quantum confinement and edge effects. In this review, the state-of-the-art knowledge of GQDs is presented. The synthetic methods were summarized, with emphasis on the top-down routes which possess the advantages of abundant raw materials, large scale production and simple operation. Optical properties of GQDs are also systematically discussed ranging from the mechanism, the influencing factors to the optical tunability. The current applications are also reviewed, followed by an outlook on their future and potential development, involving the effective synthetic methods, systematic photoluminescent mechanism, bandgap engineering, in addition to the potential applications in bioimaging, sensors, etc.
Here, the electrocatalytic activity of a single graphene sheet is mapped using electrochemiluminescence (ECL) microscopy with a nanometer resolution. The achievement of this high-spatial imaging ...relies on the varied adsorption of hydrogen peroxide at different sites on the graphene surface, leading to unsynchronized ECL emission. By shortening the exposure time to 0.2 ms, scattered ECL spots are observed in the ECL image that are not overlaid with the spots in the consecutive images. Accordingly, after stacking all the images into a graph, the ECL intensity of each pixel could be used to reflect the electrocatalytic features of the graphene surface with a resolution of 400 nm. This novel ECL method efficiently avoids the long-standing problem of classic ECL microscopy regarding the overlap of ECL emissions from adjacent regions and enables the nanometer spatial resolution of ECL microscopy for the first time.
High spatial electrochemiluminescence microscopy is established to map the electrocatalytic activity of a single graphene sheet with a nanometer resolution.
Generating collective opinion based on probability distribution function aggregation occupies crucial roles in accomplishing probabilistic risk analysis, probabilistic-forecast-based prediction, and ...uncertain assessment tasks. However, rare efforts have been paid to exploring collective opinion generation based on massive quantified judgments from large-scale experts. In this study, we establish a novel large-scale collective opinion generation paradigm based on probability distribution function aggregation to accomplish complicated assessment and evaluation tasks in decision analysis. To this end, we reformulate the existing bi-objective optimization model with the exclusion of the consensus dimension and inclusion of fairness concern among subject matter experts. The formulation of collective fairness utility uses the notion of aggregation functions and contributes to the establishment of large-scale collective opinion generation paradigm with capabilities of modeling distinct fairness distributions among the subject matter experts. The established fairness-aware large-scale collective opinion generation model advocates an adjusted bi-objective optimization model that maximizes the confidence level and fairness utility within the decision group for opinion aggregation on both intra-group and inter-group levels. It is endowed with the flexibility to be combined with context-specific expert classification and criterion weight assignment techniques to generate powerful large-scale group decision making prototypes that accommodate with diversifying decision-making scenarios. We apply the proposed fairness-aware large-scale collective opinion generation framework to the assessment of blockchain adoption barriers in medical supply chain to demonstrate its rationality and effectiveness.
•We define the individual and collective fairness utilities.•We build the fairness-aware collective opinion generation framework.•We establish the fairness-aware large-scale collective opinion generation paradigm.•We apply the proposed model to the assessment of blockchain adoption barriers.
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•The great potential of multifunctional nanomaterials for ECL bioanalysis is presented.•Deep insights into nanomaterials-based ECL biosensing strategies are discussed.•Recent ...significant developments of nanomaterials-based ECL biosensors are reviewed.•Novel applications of ECL resonance energy transfer and ECL imaging are highlighted.•Future challenges and prospects of nanomaterials-based ECL bioanalysis are concluded.
Nanomaterials with wonderful optical, electrical and chemical properties are widely studied in recent decades. In electrochemiluminescence (ECL) sensing area, nanomaterials have also gained crescent attention for their excellent performance based on different functions, such as innovative luminophores, molecule carriers, electrode modification materials and reaction catalysts. Deep insight into ECL biosensing strategies with multifunctional nanomaterials will benefit the design of advanced sensors. Based on this, nanomaterials-based ECL biosensors have shown more promising potentials than traditional ones in analytical applications. After a brief overview of basic ECL principles and sensing approaches, herein, a general description of nanomaterials-based ECL biosensing is presented, especially with emphasis on recently developed ECL resonance energy transfer (ECL-RET) strategy. Finally, future outlooks are considered in building sensitive ECL biosensors.
Hydroxyphenol compounds are often used as reductants in controlling the growth of nanoparticles. Herein, dopamine was used as an effective reductant in seed-mediated synthesis of gold nanorods ...(GNRs). The as-prepared GNRs (83 × 16 nm) were monodisperse and had a high degree of purity. The conversion ratio from gold ions to GNRs was around 80%. In addition, dopamine worked as an additive. At a very low concentration of hexadecyltrimethylammonium bromide (CTAB; 0.025 M), thinner and shorter GNRs (60 × 9 nm) were successfully prepared. By regulating the concentration of silver ions, CTAB, seeds, and reductant, GNRs with longitudinal surface plasmon resonance (LSPR) peaks ranging from 680 to 1030 nm were synthesized. The growth process was tracked using UV–vis–NIR spectroscopy, and it was found that a slow growth rate was beneficial to the formation of GNRs.
Lead halide perovskite quantum dots (QDs) are promising electrochemiluminescence (ECL) nanoemitters due to their fascinating photophysical properties. However, due to their poor structural stability ...against the external environment, the trade‐off between their colloidal stability and carrier injection/transport efficiency is a major challenge in the advancement of perovskite‐based ECL technology. In this work, intense and stable ECL from CsPbBr3 (CPB) QDs is achieved by simultaneously encapsulating CPB QDs and coreactant (CoR) into in situ generated SiO2 matrix via hydrolysis of tetramethyl orthosilicate. The well‐designed architecture of the as‐obtained CPB‐CoR@SiO2 nanocomposites (NCs) guarantees not only greatly improved stability thanks to the peripheral SiO2 protecting matrix, but also efficient self‐enhanced ECL between CPB and the intra‐coreactants. Consequently, by elaborately selecting the CoR molecules with different tertiary/secondary amines and functional groups, multifold higher (up to 10.2 times) ECL efficiencies are obtained for the CPB‐CoR@SiO2 NCs alone in reference to the standard Ru(bpy)32+/tri‐n‐propylamine system. This work provides an efficient design strategy for obtaining stable and highly efficient ECL from perovskite QDs, and offers a new perspective for the development and application of perovskite‐based ECL system.
Ternary CsPbBr3 perovskite suprastructures with self‐enhanced electrochemiluminescence and improved stability is prepared by simultaneously encapsulating CsPbBr3 quantum dots and coreactant into in situ generated SiO2 matrix via hydrolysis of tetramethyl orthosilicate. The obtained nanocomposites exhibit higher (up to 10.2 times) electrochemiluminescence efficiencies in reference to the standard Ru(bpy)32+/tri‐n‐propylamine system.
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