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The synthesis of hierarchical nanosized zeolite materials without growth modifiers and mesoporogens remains a substantial challenge. Herein, we report a general synthetic approach to produce hierarchical nanosized single-crystal aluminophosphate molecular sieves by preparing highly homogeneous and concentrated precursors and heating at elevated temperatures. Accordingly, aluminophosphate zeotypes of LTA (8-rings), AEL (10-rings), AFI (12-rings), and -CLO (20-rings) topologies, ranging from small to extra-large pores, were synthesized. These materials show exceptional properties, including small crystallites (30-150 nm), good monodispersity, abundant mesopores, and excellent thermal stability. A time-dependent study revealed a non-classical crystallization pathway by particle attachment. This work opens a new avenue for the development of hierarchical nanosized zeolite materials and understanding their crystallization mechanism.

A DNA immobilization-free ECL aptasensor was developed for the detection of 8-hydroxy-2'-deoxygunosine based on the diffusion mediated ECL quenching effect. This ECL aptasensor exhibited a high sensitivity and low detection limit by combining homogeneous DNA reaction with dual signal amplifications: target-induced multi-DNA release and Exo I-assisted target recycling.

Most electrochemiluminescence (ECL) studies focus on the single emission of luminophores, which severely limits the development of the multi-color ECL fundamental theory and applications. Herein, we prepared a multi-color ECL supramolecular nanomaterial self-assembled by 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) and aniline (An) through hydrogen bonding. This PTCDA-An supramolecular nanomaterial simultaneously produced multi-color emissions peaking at 486, 692 and 760 nm with K2S2O8 as a coreactant. These multi-color emissions were assigned to the excited PTCDA monomer (486 nm), H-dimer (692 nm) and J-dimer (760 nm). The simultaneously increased dual-color ECL intensity significantly enhanced the total ECL intensity of PTCDA-An. Furthermore, this highly efficient ECL nanomaterial was used as an ECL platform to construct a label-free immunosensor for tumor marker carcinoembryonic antigen (CEA) detection. The total ECL intensity of the immunosensor sensitively decreased due to the simultaneously decreased ECL of multiple emissions. Also, this immunosensor exhibited a wide linear range from 1 pg mL-1 to 10 μg mL-1 with a low detection limit of 0.23 pg mL-1. The multi-color ECL from the same luminophore PTCDA in this work also provides a new perspective for multi-color ECL biomaterial design.

In this work, a method for quantifying the activity of formamidopyrimidine DNA glucosylase (Fpg) was designed based on phosphate group (P)-modulated multi-enzyme catalysis and fluorescent copper nanoclusters (CuNCs). By eliminating 8-oxoguanine from double-stranded DNA, Fpg generates a nick with P at both 3' and 5' termini. Subsequently, part of the DNA is digested by 5'P-activated lambda exonuclease (λ Exo), and the generated 3'P disables exonuclease I (Exo I), resulting in the generation of single-stranded DNA containing poly(thymine) (poly(T)). Using poly(T) as templates, CuNCs were prepared to emit intense fluorescence as the readout of this method. However, in the absence of Fpg, the originally modified 5'P triggers the digestion of λ Exo. In this case, fluorescence emission is not obtained because CuNCs cannot be formed without DNA templates. Therefore, the catalysis of λ Exo and Exo I can be tuned by 5'P and 3'P, which can be further used to determine the activity of Fpg. The fluorescent Fpg biosensor works in a "signal-on" manner with the feature of "zero" background noise, and thus shows desirable analytical features and good performance. Besides, Fpg in serum samples and cell lysate could be accurately detected with the biosensor, indicating the great value of the proposed system in practical and clinical analysis.

In this work, an ultrasensitive aptasensor for the detection of Mucin 1 (MUC1) was presented based on the target-induced catalytic hairpin assembly combined with excellent mimic peroxidase performance of PtPd bimetallic nanoparticles (PtPdNPs). Traditionally, the cyclic reuse of target protein was achieved by protein conversion with enzyme cleavage or polymerization, which is costly and complex. However, in this work, it can be performed by simple strand displacement. In addition, PtPdNPs, a mimic peroxidase, was used a probe to catalyze the oxidation of tetramethylbenzidine (TMB) by H2O2, leading to the electrochemical signal amplification. With this ingenious design, the prepared aptasensor for MUC1 detection showed a favorable linear response from 100 fg mL−1 to 1 ng mL−1 and a relatively low detection limit of 16 fg mL−1. The proposed biosensor possessed acceptable stability, selectivity and reproducibility for MUC1 assay. Additionally, the fabricated aptasensor has been successfully applied to detect MUC1 in serum samples with satisfactory results. This new strategy supplied one efficient approach to improve signal amplification, which also open an avenue for sensitivity enhancement in targets detection.

An abnormal spontaneous degradation of polycrystalline Si thin-film transistors (TFTs) subject to dynamic bending stress is reported. Dynamic mechanical bending along either the channel-width or length direction causes degradation in flexible low-temperature polycrystalline Si TFTs, such as on-state current increase and threshold voltage positive shift. However, after the mechanical stress is removed, TFTs stored in a normal ambient continue to degrade spontaneously, with similar degradation behaviors. The amount of spontaneous degradation can be larger than the mechanical bending-induced degradation and is the most significant for a moderate number of bending cycles. The spontaneous degradation is a new challenge to TFT reliability under mechanical stress.

A selective and sensitive photoelectrochemical (PEC) aptasensor for AFB1 detection in corn samples was fabricated by introducing BiOBr/nitrogen-doped graphene nanoribbons (N-GNRs) as photoactive interface. As efficient visible-light-driven photoactive species, the prepared BiOBr/N-GNRs exhibited higher photoactivity than pure materials under visible light irradiation. N-GNRs, acting as promising supporters for nanomaterials, can improve the performance of composites. UV–vis diffuse reflectance spectroscopy demonstrated that BiOBr/N-GNRs possessed the narrower band gap energy, which could be easily irradiated by visible light. In addition, steady-state photoluminescence (PL) spectra also revealed that BiOBr/N-GNRs exhibited the lower recombination rate of photogenerated electron−hole pairs. The formation of the aptamer-AFB1 complex increased the resistance of the electrode, restrained the electron transfer, and thus quenched the PEC signal. Thereafter, a “signal-off” PEC aptasensor was fabricated successfully. The proposed PEC aptasensor demonstrated sensitive detection of AFB1 in a wide range from 5 pg mL−1 to 15 ng mL−1 with a low detection limit of 1.7 pg mL−1 and possessed high specificity and good reproducibility. The PEC aptasensor was suitable for corn samples with a good recovery in the range of 98.0–102.0% and the relative standard deviation (RSD) of 1.7–2.1% to confirm practical utility. Furthermore, this strategy would be extended to detect different targets as versatile PEC devices by replacing the aptamers with other sequences.

Degrading health-threatening organic pollutants (HTOPs) in water systems through advanced oxidation processes (AOPs) is an effective way to treat environmental wastewater; however, such processes require advanced catalysts. This study combined complexation effects and structural confinement strategies to rapidly prepare Co2+-isolated metal–organic framework polymers and utilized a thermal treatment process to achieve the efficient anchoring of atom-dispersed Co in a boron–carbon-nitrogen matrix (denoted as SACoN/BCN), which can improve the utilization of Co catalytic sites. SACoN/BCN effectively activated peroxymonosulfate (PMS), with the ratio and mineralization rate of sulfamethazine (SMT) removed by degradation within 40 min reached 95.2 % and 70.0 %, respectively. Radical inhibition experiments and electron paramagnetic resonance (EPR) tests showed that 1O2 generated from SACoN/BCN-activated PMS was the key reactive oxygen species that promoted HTOP degradation. Density functional theory calculations revealed that, following the introduction of electron-deficient B heteroatoms, electrons in PMS will be injected into SACoN/BCN, thereby realizing strong adsorption and further activation of PMS. The cytotoxicity of SACoN/BCN is almost negligible because of the chemical bonding (or entrapment) of Co atoms in the inorganic boron–carbon-nitrogen matrix, thereby preventing Co from forming mobile CoII ions in the aqueous system. This research provides information for advanced catalysts for the removal of HTOPs and experimental and theoretical inspiration for the preparation of single-atom catalysts for advanced oxidation processes and the mechanism of PMS activation.

Simple and sensitive detection of telomerase activity is of vital importance for both early diagnosis and therapy of malignant tumors. Inspired by DNA-biobarcode amplification reported by Chad A. Mirkin, we developed a facile DNA-biobarcode-like SERS-based copper-mediated signal amplification strategy for sensitive detection of telomerase activity. In this strategy, a duplex DNA constructed by hybridization of a copper oxide nanoparticle (CuO NP)-labeled reporting sequence (RS) with the telomerase primer sequence (TS) is ingeniously designed, and anchored on the magnetic bead (MB) to build the CuO NPs-encoded magnetic bead (MB-CuO NPs) detection probe. Upon selective sensing of telomerase, telomerase elongation reaction and structure change of TS products make the CuO NP-RS displace and separate from MB. The separated CuO NPs are dissolved into a mass of Cu2+, which prompt monodisperse dopamine-functionalized AgNPs (D-AgNPs) signal probe into aggregation, resulting in color changes and significantly enhancing of SERS signal. The SERS signal increases with the increase of Cu2+, which is directly proportional to the telomerase. Benefiting from the transformation of CuO NP to Cu2+ with a high amplification effect, this strategy could realize the telomerase activity measurement down to 3 HeLa cells and a dynamic range of 10–10000 cells. It shows a significant improvement of sensitivity without need for other enzymes and elaborate design, which escapes from the complicated manipulations and design in polymerase chain reaction (PCR) and DNA amplification techniques. Moreover, with this strategy, telomerase activities of different cell lines and telomerase inhibitors screening were successfully performed. Significantly, it can also be utilized for visual detection of telomerase, which validates the potential on-site application and its application as point-of-care testing (POCT) for efficient monitoring. Given the high-performance for telomerase analysis, the strategy has a promising application in biological detection and clinical diagnosis, as well as point-of-care tests.

In the present work, hematite–boron-carbonitride (Fe2O3–BCN) nanosheets were synthesized by a simple hydrothermal reaction and the following high temperature treatment. The morphology, structure and chemical composition of the as-prepared material were carefully characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The Fe2O3–BCN nanosheets were used to modified on the surface of the glassy carbon electrode to fabricate an electrochemical sensor for lead ions (Pb(II)) via differential pulse anodic stripping voltammetry (DPASV). At the same time, the influence of the modification concentration, solution acidity, deposition potential and deposition time on response peak current of Pb(II) at the Fe2O3–BCN-based electrochemical sensor was well investigated. Under the optimized conditions, the electrochemical signal and concentration of Pb(II) show two-stage linear relationship in the range of 0.5 – 40 μg/L and 40 –140 μg/L, with a limit of detection (LOD) of 0.129 μg/L. The Fe2O3–BCN-based electrochemical sensor shows excellent selectivity and anti-interference ability in the anti-interference experiments and actual sample analysis experiments, revealing its broad application in environmental monitoring of Pb(II).

Background Desmoid-type fibromatosis (DTF) is a rare kind of soft-tissue tumors of unknown origin, which is a benign mesenchymal neoplasm with monoclonal proliferation with local invasion, easy recurrence and non-distant metastasis. It is usually arising from the aponeurosis, muscle, and deep fascia, but DTF arsing from the fat layer have not been previously reported. Case presentation: A 22-year-old male was presented with a recurrence of lower abdominal wall mass(LAWM) after multiple operations and a new mass in the skin flap donor area of the right abdominal wall. Magnetic resonance imaging (MRI) revealed multiple soft tissue masses and nodules in the subcutaneous fat layer of the lower abdomen and right abdomen wall, which was considered a diagnosis of fibrosarcoma, then pathological consultation was performed on the paraffin specimens from previous operations, and finally confirmed the diagnosis of desmoid-type fibromatosis in combination with pathological characteristics of the resected specimens in this visit. In general, DTF did not have the ability to metastasize, but we extracted paraffin sections and performed full exon sequencing. After personalized analysis, the results showed that there was a possibility of implantative metastasis. Due to the aggressive growth and recurrence of the tumor, the patient was subsequently treated with radiotherapy and no recurrence was observed 6 months later. Continued follow-up is ongoing. Conclusions We report the first case of DTF that occurs in the superficial layer of fat with the possibility of surgically induced implantative metastasis, for such patients, diagnosis of DTF is more difficult and surgical treatment should be treated with greater caution.

Hypercrosslinked pyrrole was synthesized via the Friedel–Crafts reaction and then carbonized to obtain urchin-like nitrogen-doped carbon (UNC). Ultrasmall iron oxide nanoparticles were then supported on UNC, and the composite was used to prepare an electrochemical sensor for detecting uric acid (UA) in human urine. FexOy/UNC was characterized and analyzed via scanning electron microscopy, transmission electron microscopy, energy dispersive spectrometry, X-ray diffraction, and X-ray photoelectron spectroscopy. A glassy carbon electrode (GCE) modified with FexOy/UNC was used as an electrochemical sensor to effectively identify UA. The electrochemical behavior of the FexOy/UNC-based UA sensor was studied using differential pulse stripping voltammetry, and the optimal conditions were determined by changing the amount of FexOy/UNC, pH of the buffer solution, deposition potential, and deposition time. Under optimal conditions, the FexOy/UNC-based electrochemical sensor detected UA in the range of 2–200 μM, where the limit of detection (LOD) for UA was 0.29 μM. Anti-interference experiments were performed, and the sensor was applied to the actual analysis of human urine samples. Urea, glucose, ascorbic acid, and many cations and anions present at 100-fold concentrations relative to UA did not strongly interfere with the response of the sensor to UA. The FexOy/UNC electrochemical sensor has high sensitivity and selectivity for uric acid in human urine samples and can be used for actual clinical testing of UA in urine.

Quantitative analysis of receptor protein expression is essential to give new insights into tumor-related research. Benefitting from their high sensitivity and low background, photoelectrochemical (PEC) platforms are considered as powerful tools for evaluating the expression of receptor proteins. Herein, to reduce the cytotoxicity and facilitate the subsequent assembly, l-cysteine-modified Ag-ZnIn

In the cathodic electrochemiluminescence (ECL) field, most reported luminophores produced ECL emission at high potentials (more than −1.3 V vs. Ag/AgCl), which was adverse for both fundamental studies and practical application. It was important to screen novel ECL luminophores and coreactants for the development of ECL. In this work, N,N′-dimethyl-3,4,9,10-perylenedicarboximide (PDI-CH3) is reported to produce ECL at −0.47 V using K2S2O8 as a coreactant in an aqueous system. In addition, the ECL wavelength was 689 nm, which was interpreted with the emission of excited PDI-CH3 dimers. Finally, this low-triggering-potential ECL system was used to construct sandwiched immunosensors to detect carcinoembryonic antigen (CEA) with the potential range from 0 to −0.8 V. In this immunosensor, PDI-CH3 and gold nanoparticles (AuNPs) reduced by citrate were grafted onto graphite oxide (GO) to label secondary antibodies (Ab2). This immunosensor could sensitively detect CEA with the linear response range between 1 fg mL−1 and 1 μg mL−1 and detection limit 0.29 fg mL−1. In addition, this immunosensor showed good feasibility in various cancer serum samples.

Four-terminal poly-Si thin-film transistors (TFTs), with a counter-doped body terminal connected to the floating channel, can suppress both dc and dynamic hot-carrier (HC) degradation of TFTs. With 3-D TCAD simulation, we clarify the underlying mechanisms of the suppression effect and analyze its dependence on the position and width of the body terminal. Under dc HC condition, a wider body terminal or that closer to the drain collects more holes generated from impact ionization in the drain depletion region and suppresses the parasitic bipolar junction transistor effect, subsequently reduces the kink current more effectively. Under dynamic HC condition, the body terminal injects holes at the end of the falling time of the gate pulse, partially removes the non-equilibrium state, significantly relieves the transient maximum electric field in the drain depletion region, thus suppresses the dynamic HC degradation. A wider body terminal can inject more holes and the holes injected by that closer to the drain diffuse to drain depletion region first, thus suppress the dynamic HC degradation better.

Flexible and rechargeable zinc–air batteries with high energy density and stable output voltage are promising energy sources for wearable electronics and implantable medical devices. The development of efficient bi-functional catalysts with low-cost and environmentally friendly properties has become the focus of research on rechargeable zinc–air batteries. Herein, we present the in situ growth of manganese oxide (MnOx) on carbon cloth (MnOx-CC) by incorporating a simple chemical bath deposition method with the phase transformation of MnOx driven by thermal treatment for improving the bifunctional catalytic activities for the ORR and OER. With bifunctional catalytic activities, the carbon cloth supported MnOx electrode without an additional nonconductive binder has been used to assemble an all-solid-state rechargeable zinc–air battery. The solid-state battery shows a high open circuit voltage (1.47 V), superior round-trip efficiency (62.4% after 120 cycles), long cycling life (45 h over an operating voltage of 1.2 V), and high capacity (728 mA h g−1), which is superior to those of the Pt/C and RuO2 based battery. The battery also demonstrated excellent mechanical flexibility and cycling stability without obvious performance degradation. The present work provides an efficient approach to prepare advanced bifunctional electrocatalysts for the fabrication of all-solid-state zinc–air batteries, which would meet the demand for flexible and wearable devices.

The tough challenges for the convenient and quantitative determination of circulating miRNAs (cmiRNAs) in the peripheral blood are low abundance, high interference and lack of direct digital readout. Here, we developed dual-enhanced magnetobiosensors based on cascaded nucleic acid circuits, which integrate catalyzed hairpin assembly (CHA) with the hybridization chain reaction (HCR), for sensitive, portable and digital quantitative detection of circulating miRNAs in serum by a personal glucose meter (PGM).

A sensitive and enzyme-free electrochemical aptasensor was constructed for the sensing of 8-hydroxy-2′-deoxyguanosine (8-OH-dG). In the process of constructing the aptasensor, triple signal amplification strategies were introduced to enhance the sensitivity. First, every aptamer/pDNA complex immobilized on magnetic beads could release three kinds of pDNAs when 8-OH-dG was introduced, which caused three-fold magnification of the target. Second, the released three kinds of pDNAs initiated catalyzed hairpin assembly between two hairpin DNAs (HP1 and HP2) on a gold electrode. Meanwhile, the three kinds of pDNAs were released again by a strand displacement reaction to obtain the next catalyzed hairpin assembly. Third, the emerging toehold of HP2 further induced a hybridization chain reaction (HCR) between two hairpin DNAs (HP3 and HP4), forming a long double-stranded DNA concatemer on the surface of the electrode. Finally, [Ru(NH3)6]3+, an electroactive cation, was adsorbed onto the long dsDNA concatemer by electrostatic interactions and consequently, an electrochemical signal was generated. Under this triple signal amplification, a low detection limit down to 24.34 fM has been obtained for 8-OH-dG determination, which is superior to those of most previously reported methods.

As phosphate is one of the key causes of water eutrophication, its removal from aquatic ecosystems is essential. Adsorption methods have been widely used to remove phosphate from water bodies. However, most of the adsorbents are unstable and difficult to separate from solution. In this paper, we used a simple electrospinning method to prepare a new, well-dispersed, lanthanum (La)-based porous polyacrylonitrile nanofiber (LPS) with more active sites, which improve its phosphate removal efficiency. The maximum phosphate adsorption capacity on LPS was 218.5 mg P/g (La) (50.4 mg P/g). After complete adsorption, the P/La molar ratio on LPS was 0.98. After 48 h of oscillation, the leakage of La from LPS in deionized water was only 74 μg/L, effectively ruling out secondary pollution of the water-body. Moreover, unlike most adsorbents, LPS has the advantage that it can be readily isolated from water. After treatment with LPS, the total phosphorus (TP) of a water sample from Yangzonghai Lake (Yunnan, China) was reduced to 4.2 μg/L, a value lower than the concentration threshold of eutrophication (10 μg/L) set by the United States Environmental Protection Agency (USEPA) and the first category of the surface water environmental quality standard (10 μg/L) set by China for lakes and reservoirs.

Environmental pollution is one of the largest sources responsible for human diseases and premature death worldwide. However, the methodological development of a spatiotemporally controllable and high-throughput investigation of the environmental pollution-induced biological injury events is still being explored. In this study, we describe a chemical gradient generator-aided microfluidic cell system for the dynamic study of representative environmental pollutant-induced bronchial epithelium injury in a throughput manner. We demonstrated the stability and reliability of operation-optimized microfluidic system for precise and long-term chemical gradient production. We also performed a microenvironment-controlled microfluidic bronchial epithelium construction with high viability and structure integration. Moreover, on-chip investigation of bronchial epithelium injury by benzopyrene stimulation with various concentrations can be carried out in the single device. The varying bronchial inflammatory and cytotoxic responses were temporally monitored and measured based on the well-established system. The benzopyrene directionally led the bronchial epithelium to present observable cell shrinkage, cytoskeleton disintegration, Caspase-3 activation, overproduction of reactive oxygen species, and various inflammatory cytokine (TNF-α, IL-6, and IL-8) secretion, suggesting its significant inflammatory and cytotoxic effects on respiratory system. We believe the microfluidic advancement has potential applications in the fields of environmental monitoring, tissue engineering, and pharmaceutical development.

Recently, the early screening of the genotoxicity of new chemicals and drugs calls for the envelope of micro-/nanoreactors for metabolic study. Herein, a novel light-driven enzymatic bionanoreactor is designed with the gold nanoparticle (NP)-modified carbon nanocage (Au@CNC) as a nanoreactor and meso-tetrakis(4-carboxyphenyl)porphyrin (TCPP) as a photosensitizer for cytochrome P450-mediated drug metabolism. By confining the cytochrome P450 3A4 (CYP3A4) enzyme and TCPP inside the pores of Au@CNC, a high metabolic activity is achieved by using 7-ethoxytrifluoromethyl coumarin as the substrate because of the three-dimensional hierarchical porous structure, large surface area, and fast electron transfer capacity of Au@CNC. It is noted that owing to the presence of AuNPs inside CNC, the surface hydrophilicity of CNC is much improved, which further promotes the catalytic activity of the CYP3A4 enzyme. To our knowledge, this is the first attempt to apply CNC as a bionanoreactor for NADPH-free and light-driven in vitro drug metabolism. In addition, the presented bionanoreactor exhibits a variety of advantages in terms of fast response, short assay time (10 min), high sensitivity, and good selectivity, which are expected to expedite drug screening and render potential advances in drug discovery and development.

The present work reported a simple, lable-free and sensitive electrochemical method for the detection of protein kinase A (PKA) activity. This method was based on the specific recognition of aptamer and the aptamer-induced hybridization chain reaction (HCR) amplification strategy. The aptasensor was constructed by immobilizing capture probe on a gold electrode via an Au–S bond. When adenosine triphosphate (ATP) aptamer was introduced, its one terminus hybridized with capture probe and the other hybridized with the complementary region of an auxiliary probe, which other region triggered HCR between two hairpin DNA (H1 and H2) to form a long DNA concatamer. At last a large number of electroactive methyle blue (MB) molecules were assembled on the dsDNA concatamer, which generated a significantly amplified electrochemical signal. In the presence of ATP, the HCR would not be performed because the aptamer specifically bond to ATP and the electrochemical response would decrease. However, when ATP and PKA coexisted, the electrochemical response would recovery because that ATP had been translated into ADP by PKA. So the activity of PKA could be effectively monitored according to the change of electrochemical signal. Based on the HCR amplification strategy, the aptasensor showed a wide linear range (4 − 4 ×105 U L−1) and a low detection limit (1.5 U L−1) for the detection of PKA. Furthermore, the method was applied to study the inhibitory effect of H-89 on PKA activity. The developed aptasensor was also used to the analysis of drug-induced PKA activity in cell lysates, indicating the potential application of the developed method in the fields of clinical diagnostics and discovery of new targeted drugs.

A unique and versatile ratiometric electrochemical DNA biosensor was designed for the first time by integration of homogeneous exonuclease III-assisted target recycling amplification and one-step triggered dual-signal output. The presence of the target DNA would hybridize with the specifically designed ferrocene-labeled hairpin probe (Fc-P1) and initiate homogeneous exonuclease III-assisted target recycling amplification, which led to the decrease of the local concentration of Fc-P1. The target DNA dependent amount of remaining Fc-P1 could be conveniently monitored by hybridize the remaining Fc-P1 with the methylene blue-labeled hairpin probe ((MB-PP1) on the sensor electrode to trigger the MB tags away from while the Fc tags close to the sensing interface. Therefore, such recognition event can be translated into the homogeneous amplification coupled with one-step triggered dual-signal ratiometric electrochemical readout. The proposed biosensor achieves a detection limit of 12.8 fM within a linear range of 0.02 pM to 2 nM for target DNA species related to oral cancer over expressed 1, along with a favorable specificity. More importantly, the biosensor had been applied in detection of target DNA in artificial saliva sample and provided significant potential application in clinical analysis. This strategy possessed good capacity to integrate the nuclease amplification techniques with ratiometric output modes, and would open new opportunities for sensitive detection of other biorecognition events.

Liver cancer is one of the factors that threaten human life. Highly up-regulated in liver cancer (HULC), a kind of long non-coding RNA (lncRNA), is regarded as a favorable noninvasive biomarker for the early diagnosis of hepatocellular carcinoma (HCC). So a strategy focused on improving the sensitivity of HULC detection is urgently desired. In this work, a highly sensitive electrochemiluminescent (ECL) sensor was constructed using Au@Ag core-shell nanoparticles/graphene quantum dots (Au@Ag/GQDs) as a signal indicator to detect HULC. Compared with the individual gold or silver nanoparticles, Au@Ag core-shell nanoparticles exhibited large specific surface area, better catalysis and excellent electronic transmission capacity due to the synergistic effect between Au and Ag. Thus, the ECL performance of GQDs could be greatly promoted by Au@Ag core-shell nanoparticles. Under the optimal conditions, this proposed ECL sensor exhibited ultrahigh sensitivity for quantitative detection of HULC with a wide linear range from 1 fM to 5 nM and a low detection limit of 0.3 fM (S/N = 3). These results showed that the sensor was promising for the sensitive detection of lncRNA in clinical application.

The electrochemistry of UBr3 was studied on W working electrodes in LiBr-KBr-CsBr eutectic salt at 623 K. The U(III)/U (0) redox reaction was evaluated with respect to its electrochemical behavior, diffusion and electrocrystallization properties. According to cyclic voltammetry and square wave voltammetry, the reduction of U(III) ions to U (0) metal is a one-step three-electron reaction and the oxidation of U(III) ions is an one-electron transferred reaction. Cyclic voltammograms at varied scan rates show that U(III)/U (0) redox reactions are quasi-reversible. Chronopotentiometry and Sand's equation were used to determine the diffusion coefficients of U(III) ions. The nucleation mechanisms of uranium metal deposited on W substrates with different UBr3 concentrations were predicted by using Scharifker-Hill model, which shows that the nucleation and growth mode changes from progressive mechanism to instantaneous mechanism with an increasing concentration of UBr3 in the salt. At 623 K, potentiostatic electrodeposition was conducted to prepare mass uranium. The current-time evolution curve indicates that the actual surface area of electrodeposits keeps stable. Furthermore, the macroscopic appearance and microcosmic morphology show compact structure, rather than dendrites. Bulk uranium metal was further analyzed by inductive coupled plasma atomic emission spectrometer and X-ray diffraction, which indicate that the compact uranium is high-purity metal.

Under near-infrared (NIR) light of 810 nm wavelength for irradiation, a very simple and highly sensitive photoelectrochemical (PEC) biosensing platform has been established using the localized surface plasmon resonance effect of Au nanoparticles (NPs) as signal amplification for the nondestructive analysis of living cells. The water-dispersible Ag2S quantum dots (QDs) synthesized by a one pot method were employed as photoelectrochemically active species, and they exhibited excellent PEC properties irradiated with NIR light which was chosen due to the obvious absorption and fluorescent emission in the NIR light region. After the incorporation of Au NPs on the Ag2S QDs modified ITO electrode, the photoelectric conversion efficiency was greatly increased, at ∼2.5 times that of the pure Ag2S QDs modified electrode. Additionally, 4-mercaptophenylboronic acid (MPBA) molecules, as recognition elements, self-assembled on the electrode surface through Au–S bonds. On the basis of the chemical reaction between siali...

Mechanical reliability of flexible amorphous indium–gallium–zinc–oxide (a-IGZO) thin-film transistors (TFTs) is investigated by monitoring the electrical characteristic of TFTs before and after the dynamic stretch stress up to 300k cycles. With increasing the stretch cycles degradation features in a decrease in the on-state current, an increase in the off-state current, but almost no change in the subthreshold region or the threshold voltage. An approximately linear dependence between the on-state current degradation and the stretch force is observed, from which the critical fracture strain of a-IGZO thin film is determined to be 0.42%. It is proposed that a very few number of nanoscaled mechanical-stress-induced cracks, which originate from the interface between the channel and the gate insulator, and develop into both layers, but introduce only insignificant amount of interface defects, can fully explain the observed degradation.

It is important to design a nice electrochemiluminescence (ECL) biological nanomaterial for fabricating sensitive ECL immunosensor to detect tumor markers. Most reported ECL nanomaterial was decorated by a number of mono-luminophore. Here, we report a novel ECL nanomaterial assembled by dual luminophores perylenetetracarboxylic acid (PTCA) and carbon quantum dots (CQDs). In the ECL nanomaterial, graphene was chosen as nanocarrier. Significant ECL intensity increases are seen in the ECL nanomaterial, which was interpreted with the proposed synergistic promotion ECL meachanism of PTCA and CQDs. Furthermore, this ECL nanomaterial was used to label secondary antibody and fabricate a sandwiched carcinoembryonic antigen (CEA) immunosensor. The CEA immunosensor exhibits high sensitivity and the linear semilogarithmical range was from 0.001fgmL-1 to 1ngmL-1 with low detection limit 0.00026fgmL-1. And the CEA immunosensor is also suitable for various cancers' sample detection providing potential specific applications in diagnostics.

As an important biomarker for early Alzheimer’s disease (AD) diagnostics and a valuable therapeutic target, amyloid β peptide (Aβ) in blood has attracted extensive attention concerning its detection and monitoring. The tough challenges for monitoring subtle changes of Aβ in blood are low expression and high interference from environmental factors. Here, we constructed a ratiometric sensor based on dual-emission luminescent lanthanide metal–organic coordination polymer (DE-LMOCP) as fluorescence probe for simple, sensitive and accurate detection of Aβ. The DE-LMOCP (luminol-Tb-GMP-Cu) fluorescent probe was composed of terbium ion(Tb3+) as the center metal ions, cupric ion(Cu2+) as a cofactor for Tb3+ fluorescence silence, guanine monophosphate (GMP) as a bridging ligand can strengthen the fluorescence of Tb3+, and luminol as an auxiliary ligand. In the DE-LMOCP fluorescent probe, the fluorescence of the GMP-Tb is quite weak because the existing cofactor Cu2+ prevents the energy transfer of intramolecular between GMP and Tb3+ and results in the quench of GMP-Tb fluorescence. The fluorescence of luminol acts as inner reference. In the presence of Aβ, the high binding affinity of Aβ for Cu2+ causes a remarkable emission enhancement of GMP-Tb and suppresses the quenching effect. However, the fluorescence emission of luminol remains constant as inner reference. Hence, sensitive and accurate determination of Aβ were performed by the ratio of the fluorescence of luminol (F430) to the Tb3+(F547). With this ratiometric probe, Aβ was determined with sensitivity down to 20 pM. Moreover, the ratiometric probe was successfully used to the detection of Aβ in human plasma with satisfactory results due to its capability to eliminate auto-fluorescence. Significantly, it exhibited sound specificity and selectivity to recognize Aβ1−40, and successfully applied to visual detection of Aβ, which validates the potential on-site application. Given the analytical characteristics with high sensitivity, specificity, and accuracy, the ratiometric fluorescence sensor may have great potential in applications of Aβ1−40 detection and the early diagnosis of Alzheimer’s disease, as well as point-of-care tests.

Detection of tumor biomarker plays a crucial role in the early diagnosis and treatment of cancer. Herein, hollow polymeric nanospheres with a high loading efficiency of ferrocene molecules (Fc-HPNs) were prepared by self-assembly route between polyethylenimine-Fc (PEI-Fc) and poly acrylic acid (PAA) on SiO2 nanoparticles. Using Fc-HPNs as an efficient electrochemical tag and combining dual-enzyme assisted target amplification strategy, an ultrasensitive electrochemical biosensor for the detection of circulating tumor DNA (ctDNA) was developed. The electrochemical signals were greatly enhanced due to the high loading of Fc tags on the hollow polymeric nanospheres and the catalytic effect of ascorbic acid on the reduction reaction of Fc. Furthermore, the use of the magnetic electrode avoided the tedious and complex modification process of the traditional electrode, which made the fabrication of the electrochemical biosensor facile and time-saving. The developed biosensor exhibited a fine linear response to ctDNA concentrations from 10 fM to 10 nM with a low detection limit of 1.6 fM, which shows great potential in early-stage diagnosis and treatment of cancer.

Positron annihilation lifetime (PAL) spectroscopy is widely used in the characterization of material microstructures. It has a very high sensitivity to the material defects. This paper describes how we developed a digital PAL spectrometer with two barium fluoride (Ba F 2 ) detectors and reading the data with a fast digital oscilloscope. We achieved better time performance for the digital PAL spectrometer using a multi-parameter discrimination method and various pulse smoothing algorithms. With two Ba F 2 detectors in the coincidence mode, we achieved a time resolution of 160 ps for 0.511 MeV annihilation gamma rays. The multi-parameter discrimination method implemented can remove incorrect events more effectively than the conventional energy discrimination method. With this enhancement in event discrimination, the digital PAL spectrometer’s time performance has improved, which results in more accurate PAL characterization. In a lifetime measurement, the PAL spectrometer’s time resolution is about 130 ps, which is much better than most PAL spectrometers. With the multi-parameter discrimination method, the resolution component from the incorrect events decreases drastically, and the leading edge distortion of the PAL spectrum is significantly improved.

Various fluorescent sensing systems for miRNA detection have been developed, but they mostly contain enzymatic amplification reactions and label procedures. The strict reaction conditions of tool enzymes and the high cost of labeling limit their potential applications, especially in complex biological matrices. Here, we have addressed the difficult problems and report a strategy for label-free fluorescent DNA dendrimers based on enzyme-free nonlinear hybridization chain reaction (HCR)-mediated multiple G-quadruplex for simple, sensitive, and selective detection of miRNAs with low-background signal. In the strategy, a split G-quadruplex (3:1) sequence is ingeniously designed at both ends of two double-stranded DNAs, which is exploited as building blocks for nonlinear HCR assembly, thereby acquiring a low background signal. A hairpin switch probe (HSP) was employed as recognition and transduction element. Upon sensing the target miRNA, the nonlinear HCR assembly of two blocks (blocks-A and blocks-B) was initiated with the help of two single-stranded DNA assistants, resulting in chain-branching growth of DNA dendrimers with multiple G-quadruplex incorporation. With the zinc(II)-protoporphyrin IX (ZnPPIX) selectively intercalated into the multiple G-quadruplexes, fluorescent DNA dendrimers were obtained, leading to an exponential fluorescence intensity increase. Benefiting from excellent performances of nonlinear HCR and low background signal, this strategy possesses the characteristics of a simplified reaction operation process, as well as high sensitivity. Moreover, the proposed fluorescent sensing strategy also shows preferable selectivity, and can be implemented without modified DNA blocks. Importantly, the strategy has also been tested for miRNA quantification with high confidence in breast cancer cells. Thus, this proposed strategy for label-free fluorescent DNA dendrimers based on a nonlinear HCR-mediated multiple G-quadruplex will be turned into an alternative approach for simple, sensitive, and selective miRNA quantification.

A simple and novel one-step triggered ratiometric electrochemical biosensor was designed for lead (Pb2+) based on the highly specific lead-dependent DNAzyme and dual-signal output mode. The biosensor consists of a thiolated methylene blue-labeled DNA (MB-P1) as catalytic probe and “signal-on” readout, and a complementary strand modified with ferrocene (Fc-P2) as substrate probe and “signal-off” output. The presence of Pb2+ could activate the DNAzyme and cleave the sessile phosphodiester of the Fc-P2 into two fragments, which lead to the departure of Fc from the sensing interface along with the single stranded MB-P1 near the electrode surface. Therefore, the Pb2+ recognition event resulted in both the “signal-on” of MB and the “signal-off” of Fc for dual-signal ratiometric electrochemical readout. Combined with the efficient recognition capacity of the designed DNAzyme and the dual-signal amplification strategy, the proposed biosensor showed a wide detection range from 0.1 nM to 5 μM with a detection limit of 45.8 pM (S/N = 3). Meanwhile, this DNAzyme-based Pb2+ biosensor exhibits reasonable selectivity, fast analytical speed, acceptable fabrication reproducibility, and operational convenience. More importantly, the system is capable of detecting Pb2+ in biological fluid such as serum, suggesting promising applications of this biosensor in on-site and real-time clinical Pb2+ detection.

In the present work a highly sensitive and selective aptasensor was developed for the determination of 8-hydroxy-2'-deoxyguanosine (8-OH-dG) based on the hybridization chain reaction (HCR) signal amplification. It was observed that the aptamer of 8-OH-dG could hybridize with the capture DNA immobilized on the gold electrode with a sticky tail left, which initiated the HCR and led to the formation of extended dsDNA structure on the electrode surface. Then the electroactive species ([Ru(NH3)6]3+, RuHex) intercalated into the dsDNA grooves to generate the amplified signal. However, in the presence of 8-OH-dG, the aptamer containing G-rich nucleic acid sequences would be induced to form a G-quadruplex structure, which made it impossible to continue the HCR. So the detection signal will significantly decrease. Under the optimal conditions, the peak current of RuHex was linear with the logarithm of 8-OH-dG concentration in the range from 10pM to 100μM with the detection limit of 2.5pM. By integrating the merits of enzyme-free amplification power of the HCR and the inherent high sensitivity of the electrochemical technique, the prepared aptasensor not only showed high sensitivity for the detection of 8-OH-dG, but also exhibited good selectivity against to the uric acid, an important interferent in the urine sample. Particularly, the aptasensor was applied to detect 8-OH-dG in urine samples with satisfactory results.

Instability of a-InGaZnO thin-film transistors is experimentally investigated under synchronized ${V}_{g}$ and ${V}_{d}$ pulses’ stress. Degradation of the transfer characteristic in the forward measurement mode is much smaller than that in the reverse mode, if a typical drain bias of 5 V is applied. The degradation is found to depend on the equivalent dc stress time rather than the pulse transition edge. Larger pulse period and/or duty ratio of the voltage pulses cause more severe degradation. The degradation is affected by the recovery phenomenon, which occurs transiently when the pulsed stress is in the “OFF” phase, and enhanced by Joule heating-induced channel temperature rise. A degradation model is proposed, in which electrons’ trapping occurs at the channel/gate oxide interface, while extra electrons’ injection via thermal-assisted tunneling and interface defects’ generation occurs within a narrow region near the drain, forming a potential barrier therein. The model explains the observed degradation satisfactorily, and the result is verified by a 2-D simulation.

The evolution of He from Zr-tritides was investigated for aging times up to about 6.5 years using analytical thermal helium desorption spectrometry (THDS). Zr films were deposited onto Mo substrates and then converted into Zr-tritides (ZrT 1.70∼1.95 ) inside a tritiding apparatus loaded with pure tritium gas. During aging, there are at least five forms of He in Zr-tritides, and more than 99% of He atoms are in the form of He bubbles. The isolated He bubbles in lattices begin to link with each other when the He/Zr atom ratio reaches about 0.21, and are connected to grain boundaries or dislocation networks at He concentration of He/Zr ≈ 0.26. An interconnected system of channels decorated by bubbles evolves from the network dislocations, dislocation loops and internal boundaries. These He filled networks are formed completely when the He/Zr atom ratio is about 0.38. Once the He/Zr reached about 0.45, the networks of He bubble penetrate to the film surface and He begins an “accelerated release”. This critical ratio of He to Zr for He accelerated release is much greater than that found previously for Ti-tritides (0.23–0.30). The difference of He retention in Zr-tritides and Ti-tritides was also discussed in this paper.

A new type of degradation phenomena featured with increased subthreshold swing and threshold voltage after negative gate bias stress (NBS) is observed for amorphous InGaZnO (a-IGZO) thin-film transistors (TFTs), which can recover in a short time. After comparing with the degradation phenomena under negative bias illumination stress (NBIS), positive bias stress (PBS), and positive bias illumination stress (PBIS), degradation mechanisms under NBS is proposed to be the generation of singly charged oxygen vacancies ( V o + ) in addition to the commonly reported doubly charged oxygen vacancies ( V o 2 + ). Furthermore, the NBS degradation phenomena can only be observed when the transfer curves after NBS are measured from the negative gate bias to the positive gate bias direction due to the fast recovery of V o + under positive gate bias. The proposed degradation mechanisms are verified by TCAD simulation.

The active region of organic thin film transistors (OTFTs) is usually sensitive to moisture and O2 in the air ambient, which hinders their practical applications. In this study, the effects of air ambient on characteristics of unpassivated 2,8-difluoro-5,11-bis (triethylsilylethynyl) anthradithiophene (dif-TES-ADT) OTFTs are clarified. The device is much more sensitive to H2O vapor than O2, although both of which cause TFT instability. To improve the environmental stability, inkjet-printed passivation of the fluoropolymer CYTOP and UV curing adhesive are compared. It is found that the CYTOP passivation is well compatible with the organic channel while the UV curing adhesive has excellent barrier ability to both H2O vapor and O2. Then CYTOP/UV adhesive bilayer passivation combining advantages of both materials is introduced to achieve stable operation of OTFTs, which can resist saturated H2O vapor and O2 for 25 days.

As a new type of nano-catalytic material, copper nanoclusters (Cu NCs) have received more and more attention in various fields such as biosensors and catalysis. In this work, an electrochemical stripping chemiluminescent (ESCL) aptamer sensor based on Cu NCs was constructed for the detection of carcinoembryonic antigen (CEA). The Cu NCs were generated using DNA duplex (the CEA aptamer and its complementary strand) as template. During the ESCL detection process, Cu NCs catalyzed the reduction of H2O2 and were gradually electrochemically oxidized to Cu2+, which both promoted the decomposition of H2O2 and thus greatly improved the ECL of luminol. CEA could specifically bind with its aptamer, so the DNA duplex was damaged, causing a decrease of Cu NCs and lower ECL signals. Under the optimized conditions, the sensor achieved a high sensitivity detection of CEA with a linear range of 0.2 fg mL−1 to 1 ng mL−1 and a detection limit of 66.67 ag mL−1 (S/N = 3). In addition, the sensor exhibited good specificity, stability and reproducibility, and the detection of actual samples obtained satisfactory results, indicating that the provided strategy has potential application prospects in clinical detection.

In this brief, a negative bias stress (NBS) induced degradation in n-type multigate polycrystalline silicon (poly-Si) thin-film transistor (TFT) is investigated. It is observed that after NBS the transfer characteristic curves shift to the negative gate bias direction and multigate TFTs degrade more than the single-gate TFTs with the same effective channel length. The observed degradation phenomenon is explained with short channel effect that is resulted from the diffusion and distribution of hole carriers in the channel, which are generated in the source/drain depletion region and swept into the channel when the junctions are reversely biased during NBS. Pronounced NBS degradation caused by increased hole carriers in the channel is also verified in NBS experiment with light illumination.

Reactive oxygen species (ROS) involved anodic charge transfer and electrochemiluminescence (ECL) of all-inorganic halide perovskite CsPbBr3 nanocrystals (NCs) were investigated in an aqueous medium with hydrogen peroxide (H2O2) as the model. CsPbBr3 NCs could be electrochemically oxidized to positively charged states by injecting holes onto the highest occupied molecular orbitals and could be chemically reduced to negatively charged states by injecting electrons onto the lowest unoccupied molecular orbitals by ROS. The charge transfer between CsPbBr3 NCs of oxidative and reductive states could bring out monochromatic ECL with onset around +0.8 V, maximum emission around 519 nm, and a full width at half-maximum around 20 nm. H2O2 could selectively enhance the anodic ECL of CsPbBr3 NCs, which not only opened a way to design a bioprocess-involved photovoltaic device with CsPbBr3 NCs but also was promising for color-selective ECL biosensing.

A novel dual-signal ratiometric electrochemical aptasensor for highly sensitive and selective detection of thrombin has been designed on the basis of signal-on and signal-off strategy. Ferrocene labeled hairpin probe (Fc-HP), thrombin aptamer and methyl blue labeled bio-bar-coded AuNPs (MB-P3-AuNPs) were rationally introduced for the construction of the assay platform, which combined the advantages of the recognition of aptamer, the amplification of bio-bar-coded nanoprobe, and the ratiometric signaling readout. In the presence of thrombin, the interaction between thrombin and the aptamer leads to the departure of MB-P3-AuNPs from the sensing interface, and the conformation of the single stranded Fc-HP to a hairpin structure to take the Fc confined near the electrode surface. Such conformational changes resulted in the oxidation current of Fc increased and that of MB decreased. Therefore, the recognition event of the target can be dual-signal ratiometric electrochemical readout in both the “signal-off” of MB and the “signal-on” of Fc. The proposed strategy showed a wide linear detection range from 0.003 to 30 nM with a detection limit of 1.1 pM. Moreover, it exhibits good performance of excellent selectivity, good stability, and acceptable fabrication reproducibility. By changing the recognition probe, this protocol could be easily expanded into the detection of other targets, showing promising potential applications in disease diagnostics and bioanalysis.

The exploration of non-noble metal catalysts for the oxygen reduction reaction (ORR) is of great significance in energy conversion devices, such as fuel cells and metal-air batteries. In this work, a hybrid catalyst composed of MnO/Ni nanoparticles anchored on porous branched nitrogen-doped carbons (MnO/Ni@BNCs) were prepared by direct pyrolyzing melamine foams containing Mn(II) and Ni (II) ions at 800 °C under N2 atmosphere. On the basis of electrochemical tests, it was found that the MnO/Ni@BNCs hybrid catalyst showed a high efficient four-electron catalytic pathway towards ORR and gave a low yield of H2O2 (< 7.53 %). It also exhibited a good catalytic stability and methanol tolerance, exceeding the commercial Pt/C catalyst. The excellent catalytic performance was attributed to the synergetic effect between high catalytic activity of MnO and high electrical conductivity of Ni. Furthermore, the high surface area and porous structure characters of carbon support, which partially inherited the microstructure of melamine foam, also benefited the electron transfer and reactive species transformation during ORR process.