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The electrocatalytic nitrate reduction reaction (NO

Hyperhalogens, a superatom featuring the highest known electron affinity (EA), have promising applications in the synthesis of superoxidizers. Contributions regarding the identified numbers and corresponding design strategies of hyperhalogens, however, are scarce. Herein, a novel and noninvasive dual external field (DEF) strategy, including the ligand field and oriented external electric field (OEEF), is proposed to construct hyperhalogens. The DEF strategy was shown to possess the power to increase Au

Superatoms are considered as promising building blocks for customizing superatomic molecules and cluster-assembly nanomaterials due to their tunable electronic structures and functionalities. Electron counting rules, which mainly adjust the shell-filling of clusters, are classical strategies in designing superatoms. Here, by employing the density functional theory (DFT) calculations, we proved that the 1,4-phenylene diisocyanide (CNC6H4NC) ligand could dramatically reduce the adiabatic ionization potentials (AIPs) of the aluminum-based clusters, which have 39, 40, and 41 valence electrons, respectively, to give rise to superalkali species without changing their shell-filling. Moreover, the rigid structure of the ligand can be used as a bridge firmly linking the same or different aluminum-based clusters to form superatomic molecules and nanowires. In particular, the bridging process was observed to enhance their nonlinear optical (NLO) responses, which can be further promoted by the oriented external electric field (OEEF). Also, the stable cluster-assembly XAl12(CNC6H4NC) (X = Al, C, and P) nanowires were constructed, which exhibit strong absorption in the visible light region. These findings not only suggest an effective ligand-field strategy in superatom design but also unveil the geometrical and electronic evolution from the CNC6H4NC-based superatoms to superatomic molecules and nanomaterials.

The Huckel’s rule, Baird’s rule, and electronic shell closure model are classical and well-established concepts in chemistry, which have long been employed in rationalizing the aromaticity/antiarom...

The core of the surface-enhanced Raman spectroscopy (SERS)-based techniques for dynamic monitoring is to realize rapid and reversible adsorption. Herein, the integration technology of electro-enhanced adsorption, solid-phase microextraction, and surface-enhanced Raman spectroscopy (EE-SPME-SERS) was developed to obtain sensitive, ultrafast, and reversible SERS response toward in situ monitoring of pharmaceuticals and personal care products (PPCPs). In the EE-SPME-SERS method, a roughened Ag fiber with Au modification (r-Ag/Au fiber) was used as the SERS substrate, SPME sorbent, and working electrode. The r-Ag/Au fiber displayed good SERS sensitivity, ultrahigh photostability, and adsorption properties. The adsorption efficiency of benzidine was 76 times accelerated in EE-SPME-SERS compared to that in static adsorption. The whole process of "sampling and detection" in EE-SPME-SERS can be finished within 1 s. Reversible adsorption and desorption can be achieved in situ by switching the direction of electric field, and the regeneration process takes only a few minutes. Simulated release of benzidine from household wastewater was in situ and dynamically monitored using this strategy. EE-SPME-SERS was proved universal for ionized PPCPs and can detect multicomponents simultaneously. In addition, EE-SPME-SERS showed very good analytical properties. Great potential of EE-SPME-SERS can be expected in environmental monitoring.

Effective acquirement of highly pure circulating tumor cells (CTCs) is very important for CTC-related research. However, it is a great challenge since abundant white blood cells (WBCs) are always co-collected with CTCs because of nonspecific bonding or low depletion rate of WBCs in various CTC isolation platforms. Herein, we designed a three-dimensional (3D) conductive scaffold microchip for highly effective capture and electrochemical release of CTCs with high purity. The conductive 3D scaffold was prepared by dense immobilization of gold nanotubes (Au NTs) on porous polydimethylsiloxane and was functionalized with a CTC-specific biomolecule facilitated by a Au-S bond before embedding into a microfluidic device. The spatially distributed 3D macroporous structure compelled cells to change migration from linear to chaotic and the densely covered Au NTs enhanced the topographic interaction between cells and the substrate, thus synergistically improving the CTC capture efficiency. The Au NT-coated 3D scaffold had good electrical conductivity and the Au-S bond was breakable by voltage exposure so that captured CTCs could be specifically released by electrochemical stimulation while nonspecifically bonded WBCs were not responsive to this process, facilitating recovery of CTCs with high purity. The 3D conductive scaffold microchip was successfully applied to obtain highly pure CTCs from cancer patients' blood, benefiting the downstream analysis of CTCs.

Developing highly efficient and economical bifunctional catalysts for overall water splitting is challenging but a great concern for the renewable energy conversion and applied catalysis towards a sustainable development. Herein, by employing first principles calculations, the catalytic performance of various transition metal (TM) atoms supported on single-layer ternary Ga2FeS4 for water splitting has been systematically investigated. Strikingly, it was evidenced that the sandwich Ga2FeS4 can form a tunable interfacial polarization field under external strain, which can effectively regulate its catalytic performance. Specifically, Au-Ga2FeS4 under a 0.5% tensile strain presents good bifunctional catalytic performance, with the low overpotentials of 0.03 and 0.48 eV, respectively, for the HER and OER, outperforming the experimentally identified Pt and IrO2. Considering the massive possibilities of these ternary substrates and the easily accessible characteristic of external strain, the findings highlighted here can provide a useful theoretical guideline for designing efficient bifunctional SACs in overall water splitting.

Arsenic speciation analysis is important for pollution and health risk assessment. Surface-enhanced Raman Spectroscopy (SERS) is supposed to be a promising detection technology for arsenic species owing to the unique fingerprints. However, further application of SERS is hampered by its poor repeatability. Herein, the role of surface silver ions on colloidal Ag was revealed in SERS analysis of arsenic species. Arsenic species were adsorbed on Ag nanoparticles (Ag NPs) driven by surface silver ions and were simultaneously sensed by the SERS "hot spots" generated from the aggregation of Ag NPs. So, the inconsistent SERS activities of Ag NPs synthesized from different batches can be significantly improved by modifying external silver ions onto Ag NPs (AgNPs@Ag

Clathrate hydrates (CHs) have recently attracted considerable research interest in fundamental science and practical applications because guest molecules with special electronic properties can be s...

As a bridge between homogeneous and heterogeneous catalyses, single-atom catalysts (SACs), especially the noble metal atoms, have received extensive attention from both the fundamental and applied perspectives recently. High cost and difficulty in synthesis are considerable factors, however, limiting the development and practical applications of SACs. Thus, seeking for non-noble SACs for substituting the noble ones is not only of vital importance but also a long-standing challenge. Herein, a surface modification strategy by introducing an oppositely charged dopant and inducing the charge transfer between the SAC and the substrate was proposed to improve the stability and catalytic performance of the non-noble Cu SAC. Using first-principles density functional theory (DFT) calculations, it was demonstrated that the introduction of C in the MoS2 monolayer (C:MoS2, experimentally available) can assist in stabilizing Cu and make it more positively charged, which will facilitate the adsorption of the reactants and further enhance the activity for CO oxidation. Strikingly, our results show that CO oxidation over Cu-C:MoS2 is more favorable than over the Pt atom deposited on the pristine MoS2 (Pt-MoS2), exhibiting its potential in noble metal substitution and low-temperature CO oxidation. Additionally, Cu-C:MoS2 was observed to have a response to visible light, which manifests that it may be a promising photocatalyst. The strategy proposed here provides an efficient route to regulate the electronic structures of SACs through charge transfer, which further promotes the reactivity of the non-noble metal SACs. We hope that this strategy can contribute to design more SACs with low cost and high efficiency, which will be beneficial for their practical applications.

Conventional electronic rules, including Jellium and Wade-Mingos rules and so on, have long been successfully dedicated to design superatoms. These rules, however, rely on altering the intrinsic properties, for example, the compositions or the number of valence electrons, of clusters, which is relatively complicated and inconvenient to manipulate, especially in experiments. Herein, by employing density functional theory calculations, the oriented external electric field (OEEF) was demonstrated to possess the capability of precisely and continuously regulating the electronic properties of clusters at will, representing a novel and noninvasive methodology in constructing stable superatoms because it hardly changes the geometries of clusters. More interestingly, the active sites formed by the charge redistribution upon the introduction of an OEEF could significantly promote the catalytic performance of the low-temperature CO oxidation over clusters. Considering the convenient source of the OEEF, the findings highlighted here may boost the potential applications of superatom-assembly nanomaterials in catalysis and materials science.

The electrocatalytic hydrogen evolution reaction (HER) is essential for future renewable and clean energy technology. Screening low-cost and highly active catalysts efficiently, however, is still a grand challenge. Herein, we symbolize a highly efficient guiding principle to govern the electrocatalytic activity of single-atom catalysts (SACs) based on AX (A = Al, Ga, In, and Tl; X = S and Se), BX2 (B = Mo and W) and ZrS2 monolayer substrates for the HER. Our results reveal that the catalytic performance of SACs for the HER is highly correlated with the electronegativity of the active site and its neighboring atoms as well as the distance between them. The descriptor was introduced to determine the activity of SACs for the HER, where the generalized principle can help to predict and design efficient electrochemical catalysts for hydrogen generation. More importantly, the identified descriptor can be acquired only from initial structures of the materials without considering other complicated processes involved in the HER, which is beneficial for screening catalysts more conveniently and quickly. Such an efficient descriptor, whose reliability has been demonstrated by more than 100 cases, may have potential applications in constructing efficient and low-cost SACs both theoretically and experimentally.

High efficient detection of effusion tumor cells (ETCs) has great clinical significance to identify malignant from benign effusions, but few strategies are designed to enrich and identify tumor cells from effusions. Herein, we developed a three-dimensional scaffold microchip (3D scaffold chip) which could efficiently isolate individual ETC and ETC cluster (ETC/cluster) from pleural effusions and ascites by molecular recognition and physical obstruction. The 3D scaffold chip could enrich ETCs with 94.7% capture efficiency from 2 mL effusions in 20 min and was successfully applied to analysis of pleural effusions or ascites from 152 patients. The results showed that patients with malignant effusions possessed a much higher number of ETC/cluster than that of patients with benign effusions and receiver operating characteristic (ROC) analysis revealed that ETC/cluster count can be used as a complementary biomarker for diagnosis of malignant effusions. Finally, univariate and multivariate logistic regression analyses were adopted to find effusion variables with statistical difference in diagnosis of malignant effusions, and three variables (ETC/cluster count and effusion carcinoembryonic antigen) were selected to establish a three-marker predictive model for differentiating malignant and benign effusions in the training set. ROC analysis revealed that the AUC (area under the curve), sensitivity, and specificity of the predictive model were 0.939, 90.4%, and 91.8%, respectively. The three-marker predictive model was successfully applied to the validation set and proved that this model was promising for clinical diagnosis of effusions from patients.

We perform a theoretical investigation about the excited state intramolecular proton transfer (ESIPT) reaction for a novel 2-(2-hydroxy-3,5-dimethyl-phenyl)-benzooxazole-5-carboxylicacid (HDPBC) system. The ultrafast excited state process is due to the low potential barrier, which should be the reason why only one fluorescence peak can be observed in previous experiment. Comparing the potential energy barriers in different aprotic solvents, we present nonpolar solvents play roles in facilitating ESIPT process for HDPBC molecule. This work not only clarifies the detailed ESIPT mechanism for the novel HDPBC system and explains experimental phenomenon, but also present that solvent effects could control the ESIPT process.

Using TDDFT method, modulating mechanism of N H-based excited-state intramolecular proton transfer by electron-withdrawing substituent cyano at the aromatic para-position of four 2-(2′-aminophenyl) benzothiazole compounds have been demonstrated at B3LYP/6-311+G(d, p)/IEFPCM theory level. The scanned potential energy curves reveal that introduction of a strong electron-withdrawing group tosyl at the amino nitrogen can remarkably facilitate the occurrence of the ESIPT reaction, whereas introduction of a weak electron-withdrawing group acetyl at the amino nitrogen or introduction of an electron-withdrawing cyano group on the benzene ring at the para-position with respect to the amino group can contribute to the ESIPT process in certain degree.

Circulating tumor cells (CTCs), escaped from solid tumor to peripheral blood, are responsible for tumor metastasis and closely relevant to cancer progression. As one of the targets of “liquid biopsy”, CTCs play an important role in noninvasive tumor diagnosis. In the past decades, various microfluidic devices have been developed to efficiently isolate and accurately numerate CTCs. However, simply enumeration of CTCs can't satisfy the requirements of downstream analysis and clinical application of CTCs. Recently, new microfluidic chips have demonstrated superior advantages in extracting more information from CTCs. In this minireview, we will summarize the classical microfluidic devices for isolating and detecting CTCs, and discuss recent advances of microfluidic chip for in-depth research of CTCs, such as heterogeneity, phenotype and genotype analysis, ex vivo expansion as well as in vivo isolation et al. Finally, we will predict future research for developing next-generation of microfluidic chip to satisfy clinical demand.

The N H-based excited-state intramolecular proton transfer process of 2-(2′-aminophenyl)benzothiazole (PBT-NH2) and its three derivatives have been explored by the time-dependent density functional theory (TD-DFT) method. The scanned potential energy curves reveal that the energy barriers of the first singlet excited state of the four compounds along the ESIPT reactions are predicted at 8.74, 8.98, 6.72 and 1.69 kcal/mol respectively, suggesting that the inclusion of a strong electron-withdrawing tosyl (Ts) group can remarkably facilitate the occurrence of the ESIPT reaction, while the involvement of an electron-donating methyl group has slight opposite effect on the ESIPT process of the amino-type hydrogen-bonding system.

The shapes of the HOMOs/LUMOs and the relative positions of adjacent molecules decide the size of the intermolecular electronic couplings., This work presents a systematic study of the conducting and optical properties of a family of aromatic di­imides reported recently and discusses the influences of side-chain substitution on the reorganization energies, crystal packing, electronic couplings and charge injection barrier of 4,5,9,10-pyrenedi­imide (PyDI). Quantum-chemical calculations combined with the Marcus–Hush electron transfer theory revealed that the introduction of a side chain into 4,5,9,10-pyrenedi­imide increases intermolecular steric interactions and hinders close intermolecular π–π stacking, which results in weak electronic couplings and finally causes lower intrinsic hole and electron mobility in t-C5-PyDI (μh = 0.004 cm2 V−1 s−1 and μe = 0.00003 cm2 V−1 s−1) than in the C5-PyDI crystal (μh = 0.16 cm2 V−1 s−1 and μe = 0.08 cm2 V−1 s−1). Furthermore, electronic spectra of C5-PyDI were simulated and time-dependent density functional theory calculation results showed that the predicted fluorescence maximum of t-C5-PyDI, corresponding to an S 1→S 0 transition process, is located at 485 nm, which is close to the experimental value (480 nm).

The singlet fission (SF) channels in many systems are controlled by the thermodynamic driving force (Switch-1) and kinetic barrier (Switch-2), both of which could be modulated by chromophore structure dynamics and solvent properties. Using

Novel SERS substrates is urgently in demand for rapid and sensitive analysis of toxic agrochemicals from food. In this work, a monodispersed tungsten disulfide quantum dots modified silver nanosphere (Ag@WS

Carbonaceous shell-coated γ-Fe2O3 nanoparticles (γ-Fe2O3@CNM) were synthesized from glucose caramelization and used as a novel magnetic solid-phase extraction medium for malachite green and crystal violet in environmental water. Malachite green and crystal violet were absorbed on to γ-Fe2O3@CNM by electrostatic and π-interactions. The morphologies, pore structures, surface functional groups, and magnetic properties of γ-Fe2O3@CNM were characterized by TEM, FTIR, hysteresis regression, Brunauer-Emmet-Teller analysis, zeta potential, XPS, and XRD. The magnetic solid-phase extraction procedure was optimized by extraction pH, absorption time, desorption solvent, and desorption time. The absorption capacities (qmax values) for malachite green and crystal violet were 34.2 and 27.9 mg g−1, respectively. After magnetic solid-phase extraction, malachite green and crystal violet were determined by LC-MS/MS. The analytical method was validated with a linear range of 0.02–20 ng mL−1, enrichment factor of 25.8 and 25.4, method detection limit of 0.004 ng mL−1, and intra-day precisions of 2.1% and 2.6% for malachite green and crystal violet, respectively. The relative recovery was found to be 73.4–101.5% for malachite green and 83.1–102.7% for crystal violet upon the application of the magnetic solid-phase extraction method to real water samples from lake, spring, sea, fishpond, and industrial waste.

Current strategies for in vitro isolation of circulating tumor cells (CTCs) fail to detect extremely rare CTCs heterogeneously distributed in blood. It is possible to devise methods for in vivo capture of CTCs based on processing almost all of the blood in the human body to improve detection sensitivity, but the complicated manipulation, biosafety concerns, and limited capture efficiency of conventional detection strategies prohibit their implementation in the clinic. Herein, we present a flexible three-dimensional (3-D) CTC-Net probe for intravascular collection of CTCs. The CTC-Net, consisting of a 3-D elastic scaffold with an interconnected, spatially distributed network accommodates a large quantity of immobilized antibodies and provides an enhanced substrate-cell contact frequency, which results in an enhanced capture efficiency and effective detection of heterogeneous CTCs. The as-prepared CTC-Net can be readily compressed and injected into blood vessels and fully unfolded to form a 3-D "fishing-net" structure for capture of the CTCs, and then retracted for imaging and downstream gene analysis of the captured CTCs. Significant advantages for the CTC-Net over currently available in vitro and in vivo procedures are demonstrated for detection of extremely rare CTCs from wild-type rats and successful capture of CTCs and CTC clusters before metastasis in the case of tumor-bearing rats. Our research demonstrates for the first time the use of a 3-D scaffold CTC-Net probe for in vivo capture of CTCs. The method shows exceptional performance for cell capture, which is readily implemented and holds great potential in the clinic for early diagnosis of cancer.

Seeking novel strategies for designing superatoms is of significance for the potential applications in cluster-assembled nanomaterials. Herein, by employing the density functional theory (DFT) calculations, the effect of the oriented external electronic field (OEEF) on the electronic and photoelectron spectroscopic properties of the superatom-polymeric Zr

The conducting and optical properties of a series of indeno[1,2-b]fluorene-6,12-dione (IFD)-based molecules have been systematically studied and the influences of butyl, butylthio and dibutylamino substituents on the reorganization energies, intermolecular electronic couplings and charge-injection barriers of IFD have been discussed. The quantum-chemical calculations combined with electron-transfer theory reveal that the incorporation of sulfur-linked side chains decreases reorganization energy associated with hole transfer and optimizes intermolecular π–π stacking, which results in excellent ambipolar charge-transport properties (μh = 1.15 cm2 V−1 s−1 and μe = 0.08 cm2 V−1 s−1); in comparison, addition of dibutylamino side chains increases intermolecular steric interactions and hinders perfect intermolecular π–π stacking, which results in the weak electronic couplings and finally causes the low intrinsic hole mobility (μh = 0.01 cm2 V−1 s−1). Furthermore, electronic spectra of butyl-IFD, butylthio-IFD and dibutylamino-IFD were simulated and compared with the reported experimental data. Calculations demonstrate that IFD-based molecules possess potential for developing novel infrared and near-infrared probe materials via suitable chemical modifications.

The water solvent is a well-known solvating medium which can stabilize unstable species in bulky water or molecular clusters, but little is known about the solvating performance of the clathrate hydrate cages and changes of molecular properties of the solutes. In this work, on the basis of the experimentally observed clathrate hydrate structures, we theoretically explore their structures and properties, taking azabenzenes (pyridazine, pyrimidine, pyrazine, and pyridine) and benzene as the guests which have negative electron affinities, focusing on stability, electron affinity, vibrational shifts, proton transfer, and especially unique solvating effect of the clathrate hydrate cavity, using the density functional theory calculations. Calculations indicate that inclusion of the guest azabenzene/benzene in the clathrate hydrate cages could considerably change the structures and properties including stability increase, the C–H stretching blue shifts of the guests, and electron affinity conversion from the neg...

The existence of abundant 4f electrons significantly increases the complexity and difficulty in precisely determining the geometric and electronic structures of the lanthanide oxide clusters. Herei...

We present an extensive density functional theory (DFT) calculations on the geometrical and electronic structures of the triatomic LaX2- (X=Al, Ga, In) clusters. Various trail structures and spin states have been attempted to determine the lowest-energy geometries of these La-doped metal clusters. The ground states of all three clusters are calculated to possess the trigonal structures with the singlet multiplicities. The calculations on molecular orbitals (MOs) and nucleus-independent chemical shift (NICS) values have been performed to examine the aromatic characteristics of the LaX2- (X=Al, Ga, In) clusters. The present calculations disclose that all these metal clusters are doubly aromatic, namely d-p hybridized σ and π aromaticity resulting from the effective overlap between the 5d atomic orbital of the La atom and the p orbitals of the IIIA group elements. Theoretical vertical detachment energies (VDEs) were also calculated to simulate the photoelectron spectra (PES) of the clusters. In addition, by adding the alkali cations (Li+ and Na+) into the LaX2- (X=Al, Ga, In) clusters, the geometries and electronic structures of the corresponding neutral salts have also been investigated to gain more insights in the potential of using these aromatic anions as building blocks.

Electrochemiluminescence (ECL) detection has attracted increasing attention as a promising analytical approach. A considerable number of studies showed that ECL intensity can be definitely improved by resonance energy transfer (RET), while the RET efficiency is strongly dependent on the distance between exited donors and acceptors. Herein we disclose for the first time a highly enhanced RET strategy to promote the energy transfer efficiency by coencapsulating the donor ([Ru(bpy)3]2+)/acceptor (CdTe quantum dots, CdTe QDs) pairs into a silica nanosphere. Plenty of [Ru(bpy)3]2+ and CdTe QDs closely packed inside a single nanosphere greatly shortens the electron-transfer path and increases the RET probability, therefore significantly enhancing the luminous efficiency. Further combining with molecularly imprinting technique, we develop a novel ECL sensor for ultrasensitive and highly selective detection of target molecules. Proof of concept experiments showed that extremely low detection limits of subfg/mL (S...

Solvated electrons have been found to exist in various media which also exhibit more intriguing properties such as superconductivity, nonlinear optical response, and so on. However, how they affect the nuclear spin properties has not been proven. In this work, we present the first detailed study on solvated-electron-triggered indirect nuclear spin–spin J-coupling using density functional theory calculations. Taking 19F as a probe, we verify the presence of unusual J couplings between two distant F atoms in HF-containing anionic clusters. These couplings occur “through solvated electron”, rather than through conventional covalent bonds or space. Solvated electron can serve as an additional channel to efficiently realize long-range J-coupling between far separated nuclei because of its dispersivity and Rydberg character. The coupling magnitude strongly depends on the unique distribution of solvated electron and its second-order interaction with solvating HF units. This work provides novel insights into the ...

Although there are some proposed explanations for fluorescence enhancement of metal ions, a phenomenon with wide applications in biosensors and chemosensors, current understanding of the quantum–mechanical origin of this photophysical behaviour is limited. To address this issue, we selected thymolphthalein-based probe (T) reported recently as model system, and investigated the photochemical and photophysical properties of T and T-Zn(II) complex. The geometry structures of T and its Zn(II) complex were optimized, and the experimental absorption spectrum were well reproduced through density functional theory (DFT) methods. Furthermore, the excited state intramolecular proton transfer (ESIPT) mechanisms of T were systematically investigated. The constructed potential energy surfaces (PESs) of T at ground (S0) and first exited (S1) states indicate that, after photo-excitation, the intramolecular single-proton transfer reaction occurs more readily with the H atom removing from O to neighboring N. Furthermore, thermodynamic analysis of the T-Zn(II) complex shows that mononuclear complex (C1) is the most thermodynamically stable structure, and the intramolecular single proton transfer process of C1 is thermodynamically unfavorable at the S1 state. Time-dependent DFT calculations show that the fluorescence emission is from the S1 states of the single-proton transfer tautomer of T, as predicted from Kasha’s rule, in comparison, the fluorescence emission of Zn(II) complex is from the S1 states of T-Zn(II) rather than its single-proton transfer tautomer. The inhibitor of Zn(II) on the single proton transfer reaction plays an important role on fluorescence enhancement.

The homeostasis of lysosomal pH is crucial in cell physiology. Developing small fluorescent nanosensors for lysosome imaging and ratiometric measurement of pH is highly demanded yet challenging. Herein, a pH-sensitive fluorescein tagged aptamer AS1411 has been utilized to covalently modify the label-free fluorescent silicon nanodots via a crosslinker for construction of a ratiometric pH biosensor. The established aptasensor exhibits the advantages of ultrasmall size, hypotoxicity, excellent pH reversibility and good photostability, which favors its application in an intracellular environment. Using human breast MCF-7 cancer cells and MCF-10A normal cells as the model, this aptasensor shows cell specificity for cancer cells and displays a wide pH response range of 4.5-8.0 in living cells. The results demonstrate that the pH of MCF-7 cells is 5.1, which is the expected value for acidic organelles. Lysosome imaging and accurate measurement of pH in MCF-7 cells have been successfully conducted based on this nanosensor via fluorescent microscopy and flow cytometry.

Carbonaceous shell-coated γ-Fe

Seeking novel superatoms with tunable electronic and magnetic properties has attracted much interest due to their potential application in cluster assembly nanomaterials. By employing density functional theory (DFT) calculations, the recently observed superatomic WC cluster was adopted as the basic unit to construct larger polymeric clusters, namely (WC)n (n = 2–7), and their structural evolution was explored to understand the growth pattern of these superatomic clusters into nanoscale materials. An unusual odd–even pattern in structural evolution was disclosed, in which the (WC)2 unit is considered as the basic building block. Moreover, W4C4 is found to possess a cubic structure, based on which the CO and PH3 ligands were attached to examine their ligation effects on W4C4. Theoretical results show that the electronic properties of W4C4 can be dramatically altered during the ligation process. Intriguingly, the continuous attachment of CO and PH3 ligands strongly increases and decreases the electron affinities (EA) and ionization potentials (IP) of the ligated W4C4 clusters, respectively, leading to the formation of superhalogen and superalkali species with high magnetic moments. The observed ligand induced strategy highlighted here could serve as an effective way to tune the electronic and magnetic properties of clusters resulting in the formation of novel superatoms. Finally, studies on the geometrical and electronic structures of the W4C4 cluster solid unveil its special 3-D cubic honeycomb geometry and metallic properties with predominant contribution from the 5d of W, which may have potential applications in electro-catalysis.

Herein current research work, we designed four new acceptor materials for small solar cell molecules with Naphthalene Di-Imide central unit by employing the wB97xd/6-31 G (d,p) and TD-wB97xd/6-31 G (d,p) level of density functional theories. Absorption properties of designed materials are excellent between the 400 nm to 510 nm with chloroform solvent and 340 nm to 490 nm in gas phase, small reorganization energy values 0.0163–0.0172 eV for electron (λe) and 0.0205–0.0257 eV for hole transfer (λh), large expected open circuit voltages (Voc) from 3.60 to 4.53 eV with respect to [6, 6]-phenyl-C61-butyric acid methyl ester (PCBM), high dipole moment strength ranging from 4.0199 to 8.9647 Debye in excited state and 3.3847 Debye to 7.2632 Debye in ground state which are very helpful for the further construction of organic solar cell (OSC) devices with improved and better power conversion efficiencies (PCEs).

Discovering the non-noble ZrO cluster as an analog of the noble metal catalyst Pd is of significance toward designing functional materials with fine-tuned properties using the superatom concept. The effect of gradually assembling the ZrO superatomic unit on the electronic structures and chemical bonding of larger ZrO–polymeric clusters, however, is unclear. Herein, by using density functional theory (DFT) calculations, the lowest-energy structures and low-lying isomers of the (ZrO)n−/0 (n = 2–5) clusters were optimized, in which every O atom in these clusters tends to connect its adjacent two Zr atoms forming metal oxygen bridge bonds. Insights into the electronic characteristics of these clusters were obtained by analyzing their molecular orbitals (MOs) and density of states (DOS). More importantly, our studies on the CO (electron acceptor) and PH3 (electron donor) ligated Zr3O3 clusters unveil that the ligation process can substantially alter the electronic properties of the clusters by tuning the HOMO and LUMO states, which may have potential applications in photovoltaics. Strikingly, the successive attachment of PH3 on Zr3O3 dramatically lowers the adiabatic ionization potential (AIP) of the ligated clusters, resulting in the formation of stable superalkali clusters with large HOMO–LUMO gaps. Furthermore, the potential of constructing the superalkali Zr3O3(PH3)5 based 1-D cluster assembled material was also examined.

Flexible and wearable electrochemiluminescence sensor was successfully designed and fabricated for non-invasively monitoring the metabolism products in sweat., Flexible and wearable chemical sensors show great capability and potential in retrieving physiologically related chemical or biochemical information from elastic and curvilinear living bodies. However, so far, no flexible electrochemiluminescence (ECL) device has been reported, though ECL measurements have been extensively investigated and widely applied in many fields. Herein, we for the first time designed and fabricated a flexible ECL sensor by immobilizing highly luminescent nanospheres on Au nanotube (Au NT) networks, and subsequently coating an elastic molecularly imprinted polymer (MIP) thereon. The as-prepared flexible ECL platform displayed successive and desirable mechanical compliance while generating a very stable ECL signal during deformation, facilitating highly selective detection of physiologically relevant chemicals from bodies. On-body wearable sampling and subsequent detection of lactate and urea from sweat showed the ECL performance of this sensor displaying desirable fidelity, reusability and high stability against disturbance. This work successfully incorporated the ECL sensing model into a flexible and wearable device, therefore providing a promising new path for non-invasively monitoring the products of metabolism for health care and biomedical investigations.

Background: This study was aimed to develop a predictive model based on a microfluidic immunoassay and effusion indexes to differentiate malignant from benign pleural effusion and ascites. Methods: 152 patients with pleural effusion or ascites were enrolled in this prospective study. All effusion specimens were submitted for analysis via microfluidic immunoassays, cytological smears and biochemical assays. Logistic regression analysis was employed to develop a predictive model of differentiating malignant from benign effusions based on effusion indexes. Findings: The sensitivity of ETC count for distinguish malignant effusions was 84.72% and the specificity was 87.5% with a cutoff value of 13.5/2ml. The sensitivity of ETC cluster count was 69.4% and the specificity was 90.0% with a cutoff value of 2.5/2ml, exceeding the diagnostic performance of cytological smears (sensitivity:59.72%). Based on the effusion indexes (including ETCs/clusters count), effusion CEA, ETCs count and ETC clusters count were selected for the creation of a predictive model to discriminate between malignant and benign effusions in the training set. ROC analysis revealed that AUC of the predictive model was 0.939 (95%CI=0.896-0.982) with a sensitivity of 90.4% and a specificity of 91.2%. Application of this predictive model to the validation set showed similar diagnostic values in distinguishing malignant from benign effusions. Interpretation: This three-marker predictive model based on a microfluidic immunoassay and effusion indexes could be employed to draw a reliable differential diagnosis between malignant and benign effusions. Funding Statement: This study was supported by grants from the National Natural Science Foundation of China (No. 81572426; 21575110 & 21721005). Declaration of Interests: All authors have no competing interests to report. Ethical Approval Statement: The study protocol was reviewed and approved by the Institutional Review Board (IRB) of Renmin Hospital of Wuhan University (No. 2018-CK64). This research was conducted in line with the guidelines established by the Declaration of Helsinki.

In the field of three‐dimensional (3D) cell culture and tissue engineering, great advance focusing on functionalized materials and desirable culture systems has been made to mimic the natural environment of cells in vivo. Mechanical loading is one of the critical factors that affect cell/tissue behaviors and metabolic activities, but the reported models or detection methods offer little direct and real‐time information about mechanically induced cell responses. Herein, for the first time, a stretchable and multifunctional platform integrating 3D cell culture, mechanical loading, and electrochemical sensing is developed by immobilization of biomimetic peptide linked gold nanotubes on porous and elastic polydimethylsiloxane. The 3D scaffold demonstrates very good compatibility, excellent stretchability, and stable electrochemical sensing performance. This allows mimicking the articular cartilage and investigating its mechanotransduction by 3D culture, mechanical stretching of chondrocytes, and synchronously real‐time monitoring of stretch‐induced signaling molecules. The results disclose a previously unclear mechanotransduction pathway in chondrocytes that mechanical loading can rapidly activate nitric oxide signaling within seconds. This indicates the promising potential of the stretchable 3D sensing in exploring the mechanotransduction in 3D cellular systems and engineered tissues., In this work, a stretchable three‐dimensional (3D) scaffold is developed with peptide linked gold nanotubes on porous and elastic polydimethylsiloxane, which integrates with functions of cell culture, mechanical stimulation, and powerful detection capability for the first time. The proposed scaffold is used for real‐time monitoring of stretch‐induced nitric oxide release from chondrocytes in exploring the mechanotransduction in 3D cellular systems.