A new electrochemical DNA biosensor for determination of anti-cancer drug chlorambucil based on a polypyrrole/flower-like platinum/NiCo2O4/pencil graphite electrode

In the current study, DNA immobilization was performed on pencil graphite (PG) modified with a polypyrrole (PPy) and flower-like Pt/NiCo₂O₄ (FL-Pt/NiCo₂O₄) nanocomposite, as a new sensitive electrode to detect chlorambucil (CHB). Energy dispersive X-ray (EDX) analysis, X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques were employed to characterize the synthesized FL-Pt/NiCo₂O₄ and PPy/FL-Pt/NiCo₂O₄ nanocomposites. Moreover, differential pulse voltammetry (DPV) was selected to assess the guanine and adenine electrochemical responses on the DNA sensor. The CHB determination was performed using the maximum currents towards adenine and guanine in the acetate buffer solution (ABS). According to the results, ds-DNA/PPy/FL-Pt/NiCo₂O₄/PGE was able to detect the different concentrations of CHB in the range between 0.018 and 200 μM, with a detection limit of (LOD) of 4.0 nM. The new biosensor was also exploited for CHB determination in real samples (serum, urine and drug), the results of which revealed excellent recoveries (97.5% to 103.8%). Furthermore, the interaction between ds-DNA and CHB was studied using electrochemistry, spectrophotometry and docking whose outputs confirmed their effective interaction.

In the current study, DNA immobilization was performed on pencil graphite (PG) modified with a polypyrrole (PPy) and flower-like Pt/NiCo₂O₄ (FL-Pt/NiCo₂O₄) nanocomposite, as a new sensitive electrode to detect chlorambucil (CHB).     

A label-free immunosensor based on PHEMA/graphene oxide nanocomposite for simultaneous electrochemical determination of alpha fetoprotein

An electrochemical immunosensor based on poly(2-hydroxyethyl methacrylate) (PHEMA)/graphene oxide (GO) nanocomposite was designed in a simple way for the ultrasensitive detection of tumor makers (alpha-fetoprotein, AFP as a model). PHEMA with excellent biocompatibility, provides a large number of sites for connecting signal molecules. After modification with signal molecules, the functional PHEMA significantly improved the sensitivity of electrochemical detection. In order to immobilize antibodies, GO was introduced and used to construct a nanocomposite as a substrate. The designed AFP immunosensor showed favorable selectivity and excellent stability. Meanwhile, it has a low detection limit of 0.403 pg mL⁻¹. Furthermore, the immunosensor was used to detect target AFP in human serum, demonstrating the feasibility of clinical diagnosis.

An electrochemical immunosensor based on poly(2-hydroxyethyl methacrylate) (PHEMA)/graphene oxide (GO) nanocomposite was designed in a simple way for the ultrasensitive detection of tumor makers (alpha-fetoprotein, AFP as a model).     

Understanding the role of Cu+/Cu0 sites at Cu2O based catalysts in ethanol production from CO2 electroreduction -A DFT study

Cu₂O based electrocatalysts generally exhibit better selectivity for C₂ products (ethylene or ethanol) in electrochemical carbon dioxide reduction. The surface characteristic of the mixed Cu⁺ and Cu⁰ chemical state is believed to play an essential role that is still unclear. In the present study, density functional theory (DFT) calculations have been performed to understand the role of copper chemical states in selective ethanol formation using a partially reduced Cu₂O surface model consisting of adjacent Cu⁺/Cu⁰ sites. We mapped out the free energy diagram of the reaction pathway from CO intermediate to ethanol and discussed the relation between the formation of critical reduction intermediates and the configuration of Cu⁺/Cu⁰ sites. The results showed that Cu⁺ sites facilitate the adsorption and stabilization of *CO, as well as its further hydrogenation to *CHO. More importantly, as compared to the high reaction energy (1.23 eV) of the dimerization of two *CO on Cu⁺/Cu⁰ sites, the preferable formation of *CHO on the Cu⁺ site makes the C–C coupling reaction with *CO on the Cu⁰ site happen under a relatively lower energy barrier of 0.58 eV. Furthermore, the post C–C coupling steps leading to the formation of the key intermediate *OCHCH₂ to C₂ compound are all thermodynamically favoured. Noteworthily, it is found that *OCHCH₂ inclines to the ethanol formation because the coordinatively unsaturated Cu⁺ site could maintain the C–O bond of *OCHCH₂, and the weak binding between *O and Cu⁺/Cu⁰ sites helps inhibit the pathway toward ethylene. These findings may provide guidelines for the design of CO and CO₂ reduction active sites with enhanced ethanol selectivity.

Cu⁺ site facilitates the adsorption and stabilization of *CO. The preferable formation of *CHO on Cu⁺ makes C–C coupling reaction happen with *CO on the adjacent Cu⁰ under a lower energy barrier. The Cu⁺/Cu⁰ sites favor the pathway toward ethanol.     

Advanced binder-free electrodes based on CoMn2O4@Co3O4 core/shell nanostructures for high-performance supercapacitors

Three-dimensional (3D) hierarchical CoMn₂O₄@Co₃O₄ core/shell nanoneedle/nanosheet arrays for high-performance supercapacitors were designed and synthesized on Ni foam by a two-step hydrothermal route. The hybrid nanostructure exhibits much more excellent capacitive behavior compared with either the pristine CoMn₂O₄ nanoneedle arrays alone or Co₃O₄ nanosheets alone. The formation of an interconnected pore hybrid system is quite beneficial for the facile electrolyte penetration and fast electron transport. The CoMn₂O₄@Co₃O₄ electrode can achieve a high specific capacitance of 1627 F g⁻¹ at 1 A g⁻¹ and 1376 F g⁻¹ at 10 A g⁻¹. In addition, an asymmetric supercapacitor (ASC) was assembled by using the CoMn₂O₄@Co₃O₄ core/shell hybrid nanostructure arrays on Ni foam as a positive electrode and activated carbon as a negative electrode in an aqueous 3 M KOH electrolyte. A specific capacitance of 125.8 F g⁻¹ at 1 A g⁻¹ (89.2% retention after 5000 charge/discharge cycles at a current density of 2 A g⁻¹) and a high energy density of 44.8 W h kg⁻¹ was obtained. The results indicate that the obtained unique integrated CoMn₂O₄@Co₃O₄ nanoarchitecture may show great promise as ASC electrodes for potential applications in energy storage.

CoMn₂O₄@Co₃O₄ core/shell arrays on Ni foam exhibit outstanding electrochemical performance for asymmetric supercapacitors with respect to high specific capacitance and high cycling stability.     

Effects of Cu2+/Zn2+ on the electrochemical performance of polyacrylamide hydrogels as advanced flexible electrode materials

Previously, solid-state electrode materials have been utilized for the fabrication of energy storage devices; however, their application is impeded by their brittle nature and ion mobility problems. To address issues faced in such a modern era where energy saving and utility is of prior importance, a novel approach has been applied for the preparation of electrode materials based on polyacrylamide hydrogels embedded with reduced graphene oxide and transition metals, namely, Cu²⁺ and Zn²⁺. The fabricated hydrogel exhibits high electrical properties and flexibility that make it a favorable candidate to be used in energy storage devices, where both elastic and electrical properties are desired. For the first time, a multi-cross-linked polyacrylamide hydrogel was constructed and compared in the presence of other electro-active materials such as reduced graphene oxide and transition metals. Polyacrylamide hydrogels embedded with reduced graphene oxide demonstrate excellent electrical properties such as specific capacitance, least impedance, low phase angle shift and AC conductivity of 22.92 F g⁻¹, 2115 Ω, 2.88° and 0.67 μδ m⁻¹ respectively as compared to Cu²⁺- and Zn²⁺-loaded hydrogels, which block all available active sites causing an increase in impedance with a parallel decrease in capacitance. The capacitance retention and coulombic efficiency calculated were 88.22% and 77.23% respectively, indicating high stability up to 150 cycles at 0.1 A g⁻¹. Storage moduli obtained were 10.52 kPa, which infers the more elastic nature of the hydrogel loaded with graphene oxide than that of other synthesized hydrogels.

A novel approach has been applied for the preparation of electrode materials based on polyacrylamide hydrogels embedded with reduced graphene oxide and transition metals, Cu²⁺ and Zn²⁺. The fabricated hydrogel exhibits high electrical properties and flexibility.     

Boosting the photocatalytic performance of Cu2O for hydrogen generation by Au nanostructures and rGO nanosheets

As a narrow band-gap semiconductor, cuprous oxide (Cu₂O) has a relatively high conduction band that can exhibit high driving force for the photocatalytic generation of hydrogen under visible light. Besides, its adjustable morphologies and abundant source also make it possible to be employed as a theoretically optimal photocatalyst. However, the low charge migration and poor stability commonly limit its practical application, and various strategies have been explored in previous studies. In this study, we have novelly utilized Au nanorod (NR) and nanobipyramid (NBP) nanocrystallites as well as rGO nanosheets to boost the photocatalytic activity of Cu₂O over hydrogen generation. The ternary rGO wrapped Au@Cu₂O with a yolk–shelled structure (y-Au@Cu₂O/rGO) was synthesized by a handy and controllable method. When excited by solar light (λ > 400 nm), it was found that the H₂ yields of Cu₂O/rGO, y-Au nanoparticle@Cu₂O/rGO, y-Au NR@Cu₂O/rGO, and y-Au NBP@Cu₂O/rGO were increased in the order of 248, 702, 1582 and 1894 μmol g⁻¹ in 4 h. The outstanding photocatalytic performances of y-Au NR@Cu₂O/rGO and y-Au NBP@Cu₂O/rGO could be attributed to the combination function of quick electron transfer of rGO and abundant near-infrared-light-driven hot carriers on Au NRs and NBPs that could inject into Cu₂O and then a quick transfer to rGO to participate in H₂ reduction. Besides the above results, it was also found that Cu₂O maintained good stability after several cycling photocatalysis tests, which could be ascribed to the migration of holes from Cu₂O to Au that prevented the photooxidation of Cu₂O. This study may give a guide to fabricating controllable and effective photocatalysts based on plasmonic metals, semiconductors, or two-dimensional nanosheets, which possess full-solar-light-driven photocatalytic activities in the future.

Au@Cu₂O/rGO exhibited boosting photocatalytic performance due to the yolk–shelled structure, abundant hot charges on Au, and quick charge transfer by rGO.     

An aptasensor for the label-free detection of thrombin based on turn-on fluorescent DNA-templated Cu/Ag nanoclusters

A highly sensitive thrombin aptasensor was constructed based on the alteration of the aptamer conformation induced by the target recognition and the turn-on fluorescence due to the proximity of two darkish DNA-templated copper/silver nanoclusters (DNA-Cu/Ag NCs). Two DNA templates were designed as the functional structures consisting of the Cu/Ag NC-nucleation segment located at two termini or one terminus and the aptamer segment in the middle of a DNA template. Two darkish DNA-Cu/Ag NCs came close to each other when the aptamer combined with the target due to the conformational alteration of the aptamer structure, resulting in an increased fluorescence signal readout. Thrombin was sensitively determined as low as 1.6 nM in the range of 1.6–8.0 nM with a high selectivity. Finally, this sensor succeeded in detecting thrombin in a real fetal bovine serum.

A highly sensitive thrombin aptasensor was constructed based on the alteration of the aptamer conformation induced by the target recognition and the turn-on fluorescence due to the proximity of two darkish DNA-templated copper/silver nanoclusters (DNA-Cu/Ag NCs).     

One-pot synthesis of CoFe2O4/rGO hybrid hydrogels with 3D networks for high capacity electrochemical energy storage devices

CoFe₂O₄/reduced graphene oxide (CoFe₂O₄/rGO) hydrogel was synthesized in situ via a facile one-pot solvothermal approach. The three-dimensional (3D) network structure consists of well-dispersed CoFe₂O₄ nanoparticles on the surfaces of graphene sheets. As a binder-free electrode material for supercapacitors, the electrochemical properties of the CoFe₂O₄/rGO hybrid hydrogel can be easily adjusted by changing the concentration of the graphene oxide (GO) precursor solution. The results indicate that the hybrid material made using 3.5 mg mL⁻¹ GO solution exhibits an outstanding specific capacitance of 356 F g⁻¹ at 0.5 A g⁻¹, 68% higher than the pure CoFe₂O₄ counterpart (111 F g⁻¹ at 0.5 A g⁻¹), owing to the large specific surface area and good electric conductivity. Additionally, an electrochemical energy storage device based on CoFe₂O₄/rGO and rGO was assembled, which exhibits a high energy density of 17.84 W h kg⁻¹ at a power density of 650 W kg⁻¹ and an excellent cycling stability with 87% capacitance retention at 5 A g⁻¹ after 4000 cycles. This work takes one step further towards the development of 3D hybrid hydrogel supercapacitors and highlights their potential application in energy storage devices.

CoFe₂O₄/reduced graphene oxide (CoFe₂O₄/rGO) hydrogel was synthesized in situ via a facile one-pot solvothermal approach.     

The preparation of label-free electrochemical immunosensor based on the Pt-Au alloy nanotube array for detection of human chorionic gonadotrophin

BackgroundHuman chorionic gonadotrophin (hCG) is a secretion of the placenta during pregnancy and gestational trophoblastic diseases. It increases as a consequence of abnormal placental invasion and placental immaturity. So, it is an important diagnostic marker of pregnancy and many diseases such as the hydatidiform mole, the choriocarcinoma, the orchic teratoma, etc.MethodsA novel amperometric immunosensor for determination of hCG was constructed by immobilizing hCG antibody on the Pt–Au alloy nanotube array which was produced by electrodepositing strategy using nanopore polycarbonate (PC) membrane at ? 0.35 V. The vertically aligned Pt -Au alloy nanotube can be considered as an electrode and therefore each of the electrodes is similar to the nanoelectrode. The determination of hCG antigen was based on its obstruction to the electrocatalytic reduction of H₂O₂ by Pt–Au alloys after binding to the surface of electrode through immunoreactions.ResultsThe electrochemical behaviors were characterized with electrochemical impedance, cyclic voltammetry and chronoamperometry. Under the optimum condition, the current response of the immunosensor is in linear relationship with concentration of hCG ranging from 25 to 400 mIU/ml with a detection limit of 12 mIU/ml. Satisfactory results were obtained for determination of hCG in serum samples.ConclusionThis sensor displayed high selectivity, long-term stability and simplicity.     

Detection of toxic choline based on Mn2O3/NiO nanomaterials by an electrochemical method

In this study, a novel in situ choline sensor was assembled by attaching the binary Mn₂O₃/NiO nanoparticles (NPs) onto a glassy carbon electrode (GCE). Initially, Mn₂O₃/NiO NPs were synthesized via a wet-chemical process and fully characterized via XRD, XPS, FESEM, EDS, FTIR and UV-Vis methods. The analytical performances of the choline sensor were evaluated by an electrochemical method in the phosphate buffer phase. The estimated linear dynamic range (LDR) was found to be 0.1 nM to 0.1 mM. The other analytical performances of the choline sensor, such as sensitivity (16.4557 μA μM⁻¹ cm⁻²) and detection limit (5.77 ± 0.29 pM), were also calculated very carefully from the calibration plot. Overall, the choline sensor exhibited a reliable reproducibility, in situ validity, selectivity, interference effect, stability, and intra-day and inter-day performances with high accuracy in a short response time. Moreover, the probe was successfully applied to detect choline in real human, mouse and rabbit serum. This fabrication route would be a novel approach for the detection of selective biochemical sensor in the healthcare and biomedical fields.

In this study, a novel in situ choline sensor was assembled by attached the binary Mn₂O₃/NiO nanoparticles onto glassy carbon electrode, which might be a reliable way to develop of future sensor in the field of biomedical and healthcare fields.     

Phenylphosphonate surface functionalisation of MgMn2O4 with 3D open-channel nanostructures for composite slurry-coated cathodes of rechargeable magnesium batteries operated at room temperature

Spinel-type MgMn₂O₄, prepared by a propylene-oxide-driven sol–gel method, has a high surface area and structured bimodal macro- and mesopores, and exhibits good electrochemical properties as a cathode active material for rechargeable magnesium batteries. However, because of its hydrophilicity and significant water adsorption properties, macroscopic aggregates are formed in composite slurry-coated cathodes when 1-methyl-2-pyrrolidone (NMP) is used as a non-aqueous solvent. Functionalising the surface with phenylphosphonate groups was found to be an easy and effective technique to render the structured MgMn₂O₄ hydrophobic and suppress aggregate formation in NMP-based slurries. This surface functionalisation also reduced side reactions during charging, while maintaining the discharge capacity, and significantly improved the coulombic efficiency. Uniform slurry-coated cathodes with active material fractions as high as 93 wt% can be produced on Al foils by this technique employing carbon nanotubes as an electrically conductive support. A coin-type full cell consisting of this slurry-coated cathode and a magnesium alloy anode delivered an initial discharge capacity of ∼100 mA h g⁻¹ at 25 °C.

Phenylphosphonate functionalisation is an easy, highly effective strategy to fabricate slurry-coated nanostructured MgMn₂O₄ cathodes for rechargeable magnesium batteries at active material fractions up to 93 wt% for rechargeable magnesium batteries cycled at 25 °C.     

A smart fluorescent biosensor for the highly sensitive detection of BRCA1 based on a 3D DNA walker and ESDR cascade amplification

Nucleic acid analysis plays an important role in the diagnosis of diseases. There is a continuous demand to develop rapid and sensitive methods for the specific detection of nucleic acids. Herein, we constructed a highly sensitive and rapid fluorescent biosensor for the detection of BRCA1 by coupling a 3D DNA walker machine with spontaneous entropy-driven strand displacement reactions (ESDRs). In this study, the 3D DNA walker machine was well activated by the target DNA; this resulted in the cyclic utilization of the target DNA and the release of intermediate DNAs. Subsequently, the free intermediate DNAs triggered the circulation process of ESDRs with the help of the assistant probe A, leading to a significant enhancement of the fluorescence intensity. Due to the robust execution of the 3D DNA walker machine and highly efficient amplification capability of ESDRs, the developed biosensing method shows a wide linear range from 0.1 pM to 10 nM with the detection limit as low as 41.44 fM (S/N = 3). Moreover, the constructed biosensor displays superior specificity and has been applied to monitor BRCA1 in complex matrices. Thus, this elaborated cascade amplification biosensing strategy provides a potential platform for the bioassays of nucleic acids and the clinical diagnosis of diseases.

Nucleic acid analysis plays an important role in the diagnosis of diseases.     

A label-free and sensitive photoluminescence sensing platform based on long persistent luminescence nanoparticles for the determination of antibiotics and 2,4,6-trinitrophenol

The rapid detection of pollutants with high sensitivity and selectivity is of considerable significance for security screening, environmental safety, and human health. In this study, we prepared persistent luminescence nanoparticles (PLNPs) and constructed a label-free sensor for sensitive and selective detection of pollutants in real samples and test papers. Following excitation, PLNPs could store absorbed light energy and release it in the form of luminescence. Compared with a fluorescence-based technique, a PLNPs-based measurement could effectively avoid background interference. Under optimal conditions, the limit of detection for TNP was found to be 10 nM, while for an antibiotic it was 5 nM. The nanoprobe was successfully applied for the detection of pollutants in real samples including milk and Dianchi Lake water samples. Due to the long-lasting afterglow nature of PLNPs, the signal-to-noise ratio could be greatly increased in complex real samples. By hand-writing with TNP solution as ink on filter paper, the photoluminescence (PL) of the part stained with TNP was immediately quenched. Moreover, after direct exposure under a UV lamp for 10 min and without further excitation, the luminescence of the test paper was investigated to avoid interferents. This PLNP material could be potentially employed as a multi-responsive luminescent sensor. In addition, these easy-to-use visual techniques could provide a powerful tool for a convenient POC assay of organic pollutants.

A highly sensitive luminescence sensor based on PLNPs for visualized detection of antibiotic and organic explosives was developed, which could eliminate the background interference, allowing low background and therefore high sensitivity.     

A hybrid composite of H2V3O8 and graphene for aqueous lithium-ion batteries with enhanced electrochemical performance

Aqueous rechargeable lithium-ion batteries (ARLBs) are regarded as a competitive challenger for large-scale energy storage systems because of their high safety, modest cost, and green nature. A kind of modified composite material composed of H₂V₃O₈ nanorods and graphene sheets (HVO/G) has been effectively made by a one-step hydrothermal method and following calcination at 523 K. XRD, SEM, TEM, and TG are used to determine the phase structures and morphologies of the composite materials. Owing to the advantage of the layered structure of H₂V₃O₈ nanorods, the excellent conductivity of the graphene sheets, and the 3D network structure of the modified composite, the ARLBs with HVO/G can deliver an adequate specific capacity of 271 mA h g⁻¹ at 200 mA g⁻¹ and have a retention rate of 73.4% after 50 cycles. The average discharge capacity of ARLB with HVO/G as anode has a considerable improvement over that of HVO/CNTs and HVO, whatever the current rate used. Moreover, we find that the diffusion coefficient of lithium-ion increases by an order of magnitude through the theoretical calculation for HVO/G ARLB. The new ARLB with HVO/G electrode is a potential energy storage system with great advantages, such as simple preparation, easy assembly process, excellent safety and low-cost environmental protection.

Aqueous rechargeable lithium-ion batteries (ARLBs) are regarded as a competitive challenger for large-scale energy storage systems because of their high safety, modest cost, and green nature.     

A colorimetric sensing platform for the determination of H2O2 using 2D–1D MoS2-CNT nanozymes

A novel colorimetric platform based on nano-composites of two-dimensional (2D) molybdenum disulfide nanosheets (MoS₂ NSs) and one-dimensional (1D) carbon nanotubes (CNTs), called 2D–1D MoS₂-CNT nanozyme, was fabricated for the selective and sensitive determination of hydrogen peroxide (H₂O₂) in soda water. The MoS₂-CNT nanozyme was synthesized through a one-step solvothermal reduction method. The introduced CNTs could effectively prevent the stacking of MoS₂ nanosheets (NSs) and not only expanded the interlayer distance of MoS₂ NSs from 0.620 nm to 0.710 nm but also improved their specific surface. Under acidic conditions, the as-prepared 2D–1D MoS₂-CNT nanozymes could oxidize the colorless 3,3′,5,5′-tetramethylbenzidine (TMB) to blue-oxidized TMB (oxTMB) in the presence of H₂O₂, resulting in enhanced peroxidase-like (POD-like) activity. The kinetic study showed that MoS₂-CNT nanozyme had stronger catalytic activity than natural horseradish peroxidase (HRP). The linear range for H₂O₂ colorimetric determination was 5.00–500 μmol L⁻¹ with a limit of detection (LOD) of 1.40 μmol L⁻¹. Furthermore, the established determination method was applied to actual samples and the recoveries of H₂O₂ spiked in soda water were in the range of 92.3–107%, showing feasibility for the analysis of food.

A novel colorimetric platform based on 2D–1D MoS₂-CNT nanozymes, was fabricated for the selective and sensitive determination of hydrogen peroxide (H₂O₂) in soda water.     

A novel electrochemical sensor for glyphosate detection based on Ti3C2Tx/Cu-BTC nanocomposite

The copper benzene-1,3,5-tricarboxylate (Cu-BTC) with outstanding chemical and physical properties, is a novel and promising material in the field of electrochemical sensing. However, it has significant limitations for direct application in electrochemical sensing due to the relatively weak conductivity of Cu-BTC. Here, the conductivity of Cu-BTC was improved by loading Cu-BTC onto two-dimensional Ti₃C₂T_x nanosheets with high conductivity. Thanks to the synergistic effect produced by the high conductivity of Ti₃C₂T_x and the unique catalytic activity of Cu-BTC, the Ti₃C₂T_x/Cu-BTC nanocomposite exhibits excellent sensing performance for glyphosate, with a low limit of detection (LOD) of 2.6 × 10⁻¹⁴ M and wider linear sensing range of 1.0 × 10⁻¹³ to 1.0 × 10⁻⁶ M. Moreover, the electrochemical sensor based on Ti₃C₂T_x/Cu-BTC also shows excellent selectivity, good reproducibility and stability.

The Ti₃C₂T_x/Cu-BTC nanocomposite exhibits excellent sensing performance for glyphosate with a low detection limit and wide detection range. Moreover, the electrochemical sensor also shows excellent selectivity, good reproducibility and stability.     

一种基于2D／3D配准的脊柱术中校正方法

背景：脊柱术前三维影像有助于诊断和治疗,术中患者体位变化将引起脊柱形态改变,致使术前影像不能反映术中实际情况,无法确保手术的顺利实施。目的：利用脊髓手术中影像校正术前脊柱模型形态。方法：实验提出了一种基于2D／3D配准的脊枉术中校正方法,借助数字影像重建技术完成术前X射线图像与CT体数据的2D／3D配准,进一步完成术中、术前X射线图像中独立椎段的特征匹配,利用上述配准结果实现术前脊柱CT模型的术中快速校正。结果与结论：采朋附有标记的颈椎标本进行实验,校正后可基本消除术前脊柱模型与术中形态的偏差,其误差可控制在1mm以内,能够满足医学临床要求。     

A comparative electrochemical study of non-enzymatic glucose,ascorbic acid,and albumin detection by using a ternary mesoporous metal oxide (ZrO2, SiO2 and In2O3) modified graphene composite based biosensor

In this study, we present an electrochemical investigation of a ternary mesoporous metal oxide (ZrO₂, SiO₂ and In₂O₃) modified graphene composite for non-enzymatic glucose, ascorbic acid, and albumin detection in urine at physiological pH. Synergetic property of ZrO₂–Ag–G–SiO₂ and In₂O₃–G–SiO₂ were investigated via cyclic voltammetry (CV) using FTO glass and copper-foil electrodes with no prerequisite of solid antacid expansion. The mesoporous ZrO₂–Ag–G–SiO₂ and In₂O₃–G–SiO₂ composites were synthesized and characterized using XRD, SEM, TEM, Raman spectroscopy, XPS, DRS, BET, and photocurrent measurements. Upon increasing the glucose concentration from 0 to 3 mM, CV results indicated two anodic peaks at +0.18 V and +0.42 V versus Ag/AgCl, corresponding to Zr³⁺ and Zr⁴⁺, respectively, considering the presence of glucose in urine. Moreover, the effects of high surface area In₂O₃–G–SiO₂ were observed upon the examination of ZrO₂–Ag–G–SiO₂. In₂O₃–G–SiO₂ demonstrated a decent electrochemical pattern in glucose, ascorbic acid, and albumin sensing. Nevertheless, insignificant synergistic effects were observed in In₂O₃-G, ZrO₂-G, and ZrO₂–G–SiO₂. In₂O₃–G–SiO₂ performed well under a wide range of electrolytes and urine, and showed no activity toward uric acid, suggesting potential for biodetection in urine.

In this study, we present an electrochemical investigation of a ternary mesoporous metal oxide (ZrO₂, SiO₂ and In₂O₃) modified graphene composite for non-enzymatic glucose, ascorbic acid, and albumin detection in urine at physiological pH.     

一种基于2D/3D配准的脊柱术中校正方法

背景:脊柱术前三维影像有助于诊断和治疗,术中患者体位变化将引起脊柱形态改变,致使术前影像不能反映术中实际情况,无法确保手术的顺利实施。目的:利用脊髓手术中影像校正术前脊柱模型形态。方法:实验提出了一种基于2D/3D配准的脊柱术中校正方法,借助数字影像重建技术完成术前X射线图像与CT体数据的2D/3D配准,进一步完成术中、术前X射线图像中独立椎段的特征匹配,利用上述配准结果实现术前脊柱CT模型的术中快速校正。结果与结论:采用附有标记的颈椎标本进行实验,校正后可基本消除术前脊柱模型与术中形态的偏差,其误差可控制在1mm以内,能够满足医学临床要求。     

A facile synthesis of nanostructured CoFe2O4 for the electrochemical sensing of bisphenol A

This work reports a novel, highly sensitive and cost-effective electrochemical sensor for the detection of bisphenol A in environmental water samples. Attractive non-noble transition metal oxide CoFe₂O₄ nanoparticles were successfully synthesized using a sol–gel combustion method and further characterized by X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy. Under optimal conditions, the CoFe₂O₄ nanoparticle modified glassy carbon electrode exhibits high electrochemical activity and good catalytic performance for the detection of bisphenol A. The linear calibration curves are obtained within a wide concentration range from 0.05 μmol L⁻¹ to 10 μmol L⁻¹, and the limit of detection is 3.6 nmol L⁻¹ for bisphenol A. Moreover, this sensor also demonstrates excellent reproducibility, stability, and good anti-interference ability. The sensor was successfully applied to determine bisphenol A in practical samples, and the satisfactory recovery rate was between 95.5% and 102.0%. Based on the great electrochemical properties and practical application results, this electrochemical sensor has broad application prospects in the sensing of bisphenol A.

A new electrochemical sensor for bisphenol A is reported. CoFe₂O₄ nanoparticles were synthesized by a sol–gel combustion method. A nanoparticle-modified glassy carbon electrode exhibited outstanding electrochemical performance for the detection of bisphenol A.