Electrochemical detection of carbendazim using molecularly imprinted poly(3,4-ethylenedioxythiophene) on Co,N co-doped hollow carbon nanocage@CNTs-modified electrode.

Precisely detecting trace pesticides and their residues in food products is crucial for ensuring food safety. Herein, a high-performance electrochemical sensing platform was developed for the detection of carbendazim (CBZ) using Co,N co-doped hollow carbon nanocage@carbon nanotubes (Co,N-HC@CNTs) obtained from core-shell ZIF-8@ZIF-67 combined with a poly(3,4-ethylenedioxythiophene) (PEDOT) molecularly imprinted polymer (MIP). The Co,N-HC@CNTs exhibited excellent electrocatalytic performance, benefitting from the synergistic effect of CNTs that provide a large specific surface area and excellent electrical conductivity, Co,N co-doped carbon nanocages that offer high electrocatalytic activity and hollow nanocage structures that ensure rapid diffusion kinetics. The conductive PEDOT-MIP provided specific binding sites for CBZ detection and significantly amplified the detection signal. The sensor showed superior selectivity for CBZ with an extremely low detection limit of 1.67 pmol L-1. Moreover, the method was successfully applied to detect CBZ in tomato, orange and apple samples, achieving satisfactory recovery and accuracy, thus demonstrating its practical feasibility.

Portable electrochemical sensing platform based on amidated GO-MOF and PEDOT:PSS for high-efficient detection of ponceau 4R.

A promising electrochemical sensing platform for the detection of ponceau 4R in food has been fabricated based on the carboxylated graphene oxide (GO-COOH), metal-organic framework (MOF) UIO-66-NH2, and poly (3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). To this end GO-COOH was covalently coupled with UIO-66-NH2 through amide reaction, endowing the material (GO-CONH-UIO-66) unique hierarchical pores and high chemical stability and as a result improving the conductivity of MOF and the dispersion of GO. After the addition of PEDOT:PSS into GO-CONH-UIO-66, the continuity and conductivity of the composite (PEDOT:PSS/GO-CONH-UIO-66) have been further enhanced, due to the high conductivity, favorable film-forming, and hydrophilic properties of PEDOT:PSS. Systematic electrochemical experiments confirm that the PEDOT:PSS/GO-CONH-UIO-66/GCE shows satisfactory electrochemical sensing properties towards the detection of ponceau 4R, with a wide linear detection range of 0.01-30 µM, a low limit of detection of 3.33 nM, and a high sensitivity of 0.606 µA µM-1 cm-2. The PEDOT:PSS/GO-CONH-UIO-66 sensing platform was successfully used to detect ponceau 4R in beverage, and the detection results were compared with  high-performance liquid chromatography. As a result, the PEDOT:PSS/GO-CONH-UIO-66 composite shows a promising application prospect for rapid detection of ponceau 4R in food and will play significant role in food safety detection and supervision.

Design, synthesis, anti-infective potency and mechanism study of novel Ru-based complexes containing substituted adamantane as antibacterial agents.

Infections caused by Staphylococcus aureus (S. aureus) are increasing difficult to treat because this pathogen is easily resistant to antibiotics. However, the development of novel antibacterial agents with high antimicrobial activity and low frequency of resistance remains a huge challenge. Here, building on the coupling strategy, an adamantane moiety was linked to the membrane-active Ru-based structure and then developed three novel metalloantibiotics: [Ru(bpy)2(L)](PF6)2 (Ru1) (bpy = 2,2-bipyridine, L = amantadine modified ligand), [Ru(dmb)2(L)](PF6)2 (Ru2) (dmb = 4,4'-dimethyl-2,2'-bipyridine) and [Ru(dpa)2(L)](PF6)2 (Ru3), (dpa = 2,2'-dipyridylamine). Notably, complex Ru1 was identified to be the best candidate agent, showing greater efficacy against S. aureus than most of clinical antibiotics and low resistance frequencies. Mechanism studies demonstrated that Ru1 could not only increase the permeability of bacterial cell membrane and then caused the leakage of bacterial contents, but also promoted the production of reactive oxygen species (ROS) in bacteria. Importantly, complex Ru1 inhibited the biofilm formation, exotoxin secretion and increased the potency of some clinical used antibiotics. In addition, Ru1 showed low toxic in vivo and excellent anti-infective efficacy in two animal infection model. Thus, Ru-based metalloantibiotic bearing adamantane moiety are promising antibacterial agents, providing a certain research basis for the future antibiotics research.

Recent advances in metal-organic framework (MOF)-based agricultural sensors for metal ions: a review.

Metal ions have great significance for agricultural development, food safety, and human health. In turn, there exists an imperative need for the development of novel, sensitive, and reliable sensing techniques for various metal ions. Agricultural sensors for the diagnosis of both agricultural safety and nutritional health can establish quality and safety traceability systems of both agro-products and food to guarantee human health, even life safety. Metal-organic frameworks (MOFs) are utilized widely for the design of diversified sensors due to their distinctive structural characteristics and extraordinary optical and electrical properties. To serve agricultural sensors better, this review is dedicated to providing a brief overview of the synthesis of MOFs, the modification of MOFs, the fabrication of MOF-based film electrodes, the applications of MOF-based agricultural sensors for metal ions, which are centered on electrochemical sensors and optical sensors, and current challenges of MOF-based agricultural sensors. In addition, this review also provides potential future opportunities for the development and practical application of agricultural sensors.

Metal-ruthenium complex based on dipyridylamine group as membrane-active antibacterial agent effectively decrease the development of drug-resistance on Staphylococcus aureus.

Staphylococcus aureus (S. aureus), one of the Gram-positive bacteria, is easily to develop drug-resistance. Drug-resistant S. aureus infection leads to high morbidity and mortality. The complexes, namely [Ru(dpa)2(PSPIP)](PF6)2 (Ru1), [Ru(dpa)2(TSPIP)](PF6)2 (Ru2), and [Ru(dpa)2(TBPIP)](PF6)2 (Ru3), were synthesized using 2, 2'-dipyridylamine as an auxiliary ligand and three main ligands PSPIP, TSPIP, TBPIP. In vitro studies demonstrated that the Ru1-3 exhibited excellent antibacterial activity against S. aureus while showing low hemolytic toxicity to rabbit red blood cells. Notably, Ru3 was found to disrupt the bacterial cell membrane and alter its permeability through fluorescence staining and scanning electron microscopy (SEM) analysis. Furthermore, Ru3 displayed low toxicity in G. mellonella Larvae. Ru3 exhibited good activity against S. aureus in G. mellonella Larvae infection model and mouse skin infection model.To some extent, Ru3 inhibited biofilm formation on S. aureus as well as hemolytic toxin production, thereby attenuating the development of drug resistance without cross-resistance with other antibiotics. In addition, complex Ru3 exhibited a synergistic effect when combined with antibiotics amikacin, kanamycin, tobramycin and chloramphenicol, making it a valuable antibiotics adjuvant.

Coumarin-modified ruthenium complexes by disrupting bacterial membrane to combat Gram-positive bacterial infection.

Antibiotic abuse has caused the generation of drug-resistant bacteria and a series of infections induced by multidrug-resistant bacteria have become a threat to human health. Facing the failure of traditional antibiotics, antibacterial drugs with new molecular and action modes urgently need to be developed. In this study, ruthenium complexes containing coumarin were designed and synthesized. By altering the structure of the ancillary ligand, we explored the biological activities of four ruthenium complexes against Staphylococcus aureus. Among them, Ru(II)-1 with the best antibacterial activity (minimum inhibitory concentration: 1.56 µg mL-1) was used for further investigations. Surprisingly, Ru(II)-1 could significantly inhibit the formation of biofilm and hinder the development of drug-resistant bacteria. Besides, Ru(II)-1 also exhibited excellent biocompatibility. Antibacterial mechanism studies suggested that Ru(II)-1 could target the bacterial cell membrane and combine with the phospholipid component of the membrane (phosphatidylglycerol and phosphatidylethanolamine) and generate reactive oxygen species to induce an oxidative stress response, which resulted in the damage of membrane integrity, finally leading bacteria death. Moreover, antibacterial tests in G. mellonella larvae and mice in vivo model indicated that Ru(II)-1 had the potential to combat S. aureus infection. Therefore, all the above results showed that ruthenium complexes modified with coumarin could be a promising antibacterial agent to tackle bacterial infection problems.

Ruthenium polypyridine complexes containing prenyl groups as antibacterial agents against Staphylococcus aureus through a membrane-disruption mechanism.

Four new ruthenium polypyridyl complexes with prenyl groups, [Ru(bpy)2 (MHIP)](PF6 )2 (Ru(II)-1), [Ru(dtb)2 (MHIP)](PF6 )2 (Ru(II)-2), [Ru(dmb)2 (MHIP)](PF6 )2 (Ru(II)-3), and [Ru(dmob)2 (MHIP)](PF6 )2 (Ru(II)-4) (bpy = 2,2'-bipyridine, dtb = 4,4'-di-tert-butyl-2,2'-bipyridine, dmb = 4,4'-dimethyl-2,2'-bipyridine, dmob = 4,4'-dimethoxy-2,2'-bipyridine, and MHIP = 2-(2,6-dimethylhepta-1,5-dien-1-yl)-1H-imidazo[4,f][1,10]phenanthroline), were synthesized and characterized. Their antibacterial activities against Staphylococcus aureus were assessed, and the minimum inhibition concentration (MIC) value of Ru(II)-2 against S. aureus was only 0.5 µg/mL, showing the best antibacterial activity among them. S. aureus could be quickly killed by Ru(II)-2 in 30 min and Ru(II)-2 displayed an obvious inhibitive effect on the formation of a biofilm, which was essential to avoid the development of drug-resistance. Meanwhile, Ru(II)-2 exhibited a stable MIC value against antibiotic-resistant bacteria. The antibacterial mechanism of Ru(II)-2 was probably related to depolarization of the cell membrane, and a change of permeability was associated with the formation of reactive oxygen species, leading to leakage of nucleic acid and bacterial death. Furthermore, Ru(II)-2 hardly showed toxicity to mammalian cells and the Galleria mellonella worm. Finally, murine infection studies also illustrated that Ru(II)-2 was highly effective against S. aureus in vivo.

Synthesis and biological evaluation of ruthenium complexes bearing the 1,2,4-triazole group as potential membrane-targeting antibacterial agents towards Staphylococcus aureus.

Bacterial infection is one of the most serious public health problems, being harmful to human health and expensive. Nowadays, the misuse and overuse of antibiotics have led to the emergence of drug resistance. Therefore, it is an urgent need to develop new antimicrobial agents to address the current situation. In this study, four 1,2,4-triazole ruthenium polypyridine complexes [Ru(bpy)2(TPIP)](PF6)2 (Ru1), [Ru(dmb)2(TPIP)](PF6)2 (Ru2), [Ru(dtb)2(TPIP)](PF6)2 (Ru3) and [Ru(dmob)2(TPIP)](PF6)2 (Ru4) (bpy = 2,2'-bipyridine, dmb = 4,4'-dimethyl-2,2'-bipyridine, dtb = 4,4'-di-tert-butyl-2,2'-bipyridine, dmob = 4,4'-dimethoxy-2,2'-bipyridine and TPIP = 2-(4-(1H-1,2,4-triazol-1-yl)phenyl)-1H-imidazo[4,5-f][1,10]phenanthroline) were synthesized and evaluated for antibacterial activity. Results showed that the minimum inhibitory concentration (MIC) value of Ru3 against Staphylococcus aureus (S. aureus) was only 0.78 µg mL-1, showing the best antimicrobial activity in vitro. Besides, Ru3 showed low hemolytic activity and good biocompatibility. Due to its ability to damage the cell membrane of Staphylococcus bacteria, Ru3 was able to kill bacteria in a short time. Importantly, by inhibiting bacterial toxins and the formation of biofilm, Ru3 was not susceptible to the development of drug resistance. Moreover, Ru3 revealed excellent therapeutic effects in vivo and showed no irritation to the skin of mice. In conclusion, the four obtained 1,2,4-triazole ruthenium polypyridine complexes show strong antibacterial activity and satisfactory biocompatibility with excellent potential for antibacterial treatment, and provide a new solution for the current antibacterial crisis.

Multi-target antibacterial mechanism of ruthenium polypyridine complexes with anthraquinone groups against Staphylococcus aureus.

Three new Ru(ii) complexes, [Ru(dtb)2PPAD](PF6)2 (Ru-1), [Ru(dmob)2PPAD](PF6)2 (Ru-2) and [Ru(bpy)2PPAD](PF6)2 (Ru-3) (dtb = 4,4'-di-tert-butyl-2,2'-bipyridine, dmob = 4,4'-dimethyl-2,2'-bipyridine, bpy = 2,2'-bipyridine and PPAD = 2-(pyridine-3-yl)-1H-imidazo[4,5f][1.10]phenanthracene-9,10-dione), were synthesized and characterized by 1H NMR and 13C NMR spectroscopy, HRMS and HPLC. Among them, Ru-1 showed excellent antimicrobial activity against Gram-positive bacteria Staphylococcus aureus (minimum inhibitory concentration (MIC) = 1 µg mL-1) and low hemolytic and cytotoxic activity. In addition, Ru-1 showed obviously rapid bactericidal activity, low resistance rate, bacterial biofilm destroying activity and high biosafety in vivo. Moreover, skin infection models and a mouse model of sepsis indicated that the anti-infective efficacy of Ru-1 was comparable to that of vancomycin. Mechanism exploration results showed that the antibacterial behavior is probably related with targeting of the bacterial cell membrane and inhibiting topoisomerase I.

TiO2-MXene/PEDOT:PSS Composite as a Novel Electrochemical Sensing Platform for Sensitive Detection of Baicalein.

In this work, TiO2-MXene/poly (3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) composite was utilized as an electrode material for the sensitive electrochemical detection of baicalein. The in-situ growth of TiO2 nanoparticles on the surface of MXene nanosheets can effectively prevent their aggregation, thus presenting a significantly large specific surface area and abundant active sites. However, the partial oxidation of MXene after calcination could reduce its conductivity. To address this issue, herein, PEDOT:PSS films were introduced to disperse the TiO2-MXene materials. The uniform and dense films of PEDOT:PSS not only improved the conductivity and dispersion of TiO2-MXene but also enhanced its stability and electrocatalytic activity. With the advantages of a composite material, TiO2-MXene/PEDOT:PSS as an electrode material demonstrated excellent electrochemical sensing ability for baicalein determination, with a wide linear response ranging from 0.007 to 10.0 µM and a lower limit of detection of 2.33 nM. Furthermore, the prepared sensor displayed good repeatability, reproducibility, stability and selectivity, and presented satisfactory results for the determination of baicalein in human urine sample analysis.

Derivation of copper water quality criteria in Bohai Bay for the protection of local aquatic life and the ecological risk assessment.

Developing effective marine water quality criteria (WQC) is crucial for controlling marine contamination and protecting marine life. The WQC for copper is urgently needed due to the toxicity and widespread of copper contamination. In this work, both short-term water quality criteria (SWQC) and long-term water quality criteria (LWQC) under 10 % effect endpoints were derived by using the model averaging of species sensitivity distribution (SSD10) method for Bohai Bay. The WQC values were obtained directly from the hazardous concentration for 5 % of species (HC5) values, which removes the influence of arbitrary assessment factor (AF). Modifications to the acute-chronic ratio (ACR) strategies and the inclusion of the test toxicity data of local species also improved the accuracy and applicability of the WQC values. The derived SWQC and LWQC were 2.21 and 0.45 µg/L, respectively. Furthermore, the overall risk level of copper in Bohai Bay was evaluated by using the risk quotient (RQ) method, and the results showed it was at a moderate-low level. This study provides a new approach for the derivation of the WQC for Cu and the risk assessment of Bohai Bay, which is essential for the protection of local aquatic life and provides guidance to the establishment of the national WQC.

Inhibition mechanism of MRTX1133 on KRASG12D: a molecular dynamics simulation and Markov state model study.

The mutant KRAS was considered as an "undruggable" target for decades, especially KRASG12D. It is a great challenge to develop the inhibitors for KRASG12D which lacks the thiol group for covalently binding ligands. The discovery of MRTX1133 solved the dilemma. Interestingly, MRTX1133 can bind to both the inactive and active states of KRASG12D. The binding mechanism of MRTX1133 with KRASG12D, especially how MRTX1133 could bind the active state KRASG12D without triggering the active function of KRASG12D, has not been fully understood. Here, we used a combination of all-atom molecular dynamics simulations and Markov state model (MSM) to understand the inhibition mechanism of MRTX1133 and its analogs. The stationary probabilities derived from MSM show that MRTX1133 and its analogs can stabilize the inactive or active states of KRASG12D into different conformations. More remarkably, by scrutinizing the conformational differences, MRTX1133 and its analogs were hydrogen bonded to Gly60 to stabilize the switch II region and left switch I region in a dynamically inactive conformation, thus achieving an inhibitory effect. Our simulation and analysis provide detailed inhibition mechanism of KRASG12D induced by MRTX1133 and its analogs. This study will provide guidance for future design of novel small molecule inhibitors of KRASG12D.

Electrochemical determination of benomyl using MWCNTs interspersed graphdiyne as enhanced electrocatalyst.

Graphdiyne (GDY) has attracted a lot of interest in electrochemical sensing application with the advantages of a large conjugation system, porous structure, and high structure defects. Herein, to further improve the sensing effect of GDY, conductive MWCNTs were chosen as the signal accelerator. To get a stable composite material, polydopamine (PDA) was employed as connecting bridge between GDY and MWCNTs-NH2, where DA was firstly polymerized onto GDY, followed by covalently linking MWCNTs-NH2 with PDA through Michael-type reaction. The formed GDY@PDA/MWCNTs-NH2 composite was then explored as an electrochemical sensor for benomyl (Ben) determination. GDY assists the adsorption and accumulation of Ben molecules to the sensing surface, while MWCNTs-NH2 can enhance the electrical conductivity and electrocatalytic activity, all of which contributing to the significantly improved performance. The proposed sensor displays an obvious oxidation peak at 0.72 V (vs. Hg|Hg2Cl2) and reveals a wide linear range from 0.007 to 10.0 µM and a low limit of detection (LOD) of 1.8 nM (S/N = 3) toward Ben detection. In addition, the sensor shows high stability, repeatability, reproducibility, and selectivity. The feasibility of this sensor was demonstrated by detecting Ben in apple and cucumber samples with a recovery of 94-106% and relative standard deviations (RSDs) less than 2.3% (n = 5). A sensitive electrochemical sensing platform was reported for benomyl (Ben) determination based on a highly stable GDY@PDA/MWCNTs-NH2 composite.

2D Leaf-Like Structured ZIF-L Embedded Electrochemically Reduced Graphene Oxide Composite as an Electrochemical Sensing Platform for Sensitively Detecting Benomyl.

In this work, a two-dimensional leaf-like framework-L embedded electrochemically reduced graphene oxide (ERGO@ZIF-L) was proposed as an outstanding electrode material for the sensitive electrochemical sensing of benomyl (BM). ZIF-L is surrounded by ERGO, which could effectively ensure the stability and dispersion of ZIF-L. With this unique combination, the prepared ERGO@ZIF-L displayed excellent synergistic characteristics with a large surface area, excellent conductivity, plentiful active sites, and high electrocatalytic properties, thus endowing it with high sensitivity for BM determination. The experimental parameters, such as solution pH, material volume, and accumulation time, were optimized. Under optimal conditions, the BM sensor showed a wide linear range (0.009-10.0 µM) and low-limit detection (3.0 nM). Moreover, the sensor displayed excellent stability, repeatability, and reproducibility, and good anti-interference capability. The method was successfully applied to detect BM in real-world samples.

Ruthenium polypyridine complexes with triphenylamine groups as antibacterial agents against Staphylococcus aureus with membrane-disruptive mechanism.

Due to the emergence and wide spread of methicillin-resistant Staphylococcus aureus, the treatment of this kind of infection becomes more and more difficult. To solve the problem of drug resistance, it is urgent to develop new antibiotics to avoid the most serious situation of no drug available. Three new Ru complexes [Ru (dmob)2PMA] (PF6)2 (Ru-1) [Ru (bpy)2PMA] (PF6)2 (Ru-2) and [Ru (dmb)2PMA] (PF6)2 (Ru-3) (dmob = 4,4'-dimethoxy-2,2'-bipyridine, bpy = 2,2'-bipyridine, dmb = 4,4'-dimethyl-2,2'-bipyridine and PMA = N-(4-(1H-imidazo [4,5-f] [1,10] phenanthrolin-2-yl) -4-methyl-N-(p-tolyl) aniline) were synthesized and characterized by 1H NMR, 13C NMR and HRMS. The detailed molecular structure of Ru-3 was determined by single crystal X-ray diffraction. Their antibacterial activities against Staphylococcus aureus (Staphylococcus aureus) were obvious and Ru-3 showed the best antibacterial effect with the minimum inhibitory concentration value of 4 µg ml-1. Therefore, further study on its biological activity showed that Ru-3 can effectively inhibit the formation of biofilm and destroy cell membrane. In vitro hemolysis test showed that Ru-3 has almost negligible cytotoxicity to mammalian red blood cells. In the toxicity test of wax moth insect model, Ru-3 exhibited low toxicity in vivo. These results, combined with histopathological studies, strongly suggest that Ru-3 was almost non-toxic. In addition, the synergistic effect of Ru-3 with common antibiotics such as ampicillin, chloramphenicol, tetracycline, kanamycin and gentamicin on Staphylococcus aureus was detected by chessboard method. Finally, in vivo results revealed that Ru-3 could obviously promote the wound healing of Staphylococcus aureus infected mice.

Ruthenium(II) complexes targeting membrane as biofilm disruptors and resistance breakers in Staphylococcus aureus bacteria.

The development of ruthenium-based complexes or antimicrobial peptides are identified as a promising strategy for combating drug-resistant bacteria. In this work, four biphenyl-based antibacterial ruthenium complexes by targeting membrane integrity, which act as antimicrobial peptides mimics, were designed and synthesized. In vitro antimicrobial screening demonstrated that four complexes could absolutely inhibit the growth of Staphylococcus aureus (S. aureus) with MIC values ranging from 15.6 to 100 µg/mL. The most active complex Ru(Ⅱ)-1 (MIC = 15.6 µg/mL) could kill S. aureus through targeting the membrane integrity without detectably resistance frequencies. Further investigation including bacteria biofilm formation, hemolysin activity and checkerboard assay were performed as well. The results revealed that Ru(Ⅱ)-1 could inhibit the biofilm formation and α-hemolysis secretion in S. aureus at subinhibitory concentration. More interestingly, the combination use of Ru(Ⅱ)-1 and five traditional antibiotics showing synergistic effect. Finally, based on the mouse model of S. aureus skin infection, Ru(Ⅱ)-1 showed important antibacterial efficacy against S. aureus in vivo, and almost non-toxic against mouse tissue. Our study indicates that introducing membrane targeting ligands onto ruthenium complexes may be an underappreciated strategy for developing antibacterial agents.

Amplified electrochemical determination of niclosamide in food based on carbon nanohorn@MWCNT composite.

In this work, carbon nanohorn (CNH)-decorated multi-walled carbon nanotube (MWCNT) (CNH@MWCNT) composite was prepared and used to modify glass carbon electrode (GCE) as sensitive electrochemical sensor for niclosamide (NA) determination. Herein, the decoration of CNHs induces higher dispersibility for MWCNTs, and endows the composite with better conductivity, larger surface area, and higher catalytic activity, which leads to significantly enhanced electrochemical behavior toward NA oxidation. The parameters such as mass ratios of CNHs and MWCHTs, the amount of composite materials, the accumulation time, and the solution pH are systematically optimized. Under optimized conditions, the developed electrochemical sensor exhibits a low detection limit of 2.0 nM with a wide linear range of 7.0 nM-10.0 µM and high anti-interference ability. In addition, the sensor displays good stability, repeatability, and reproducibility. The feasibility of the assay was verified by testing NA in brown rice and rice field water samples.

Lotus seedpods biochar decorated molybdenum disulfide for portable, flexible, outdoor and inexpensive sensing of hyperin.

Biomass waste, a good candidate for advanced carbon materials for sustainable electrodes, is receiving more and more attention for high value-added materials because of its promising contribution to economic growth and sustainable development. We proposed a green co-hydrothermal approach to prepare lotus seedpods biochar (BC) decorated molybdenum disulfide (MoS2) from waste lotus seedpods and precursors of MoS2, and a portable, flexible, outdoor and inexpensive sensing platform for hyperin on the integrated flexible three-electrode using U-disk potentiostat with smartphone was successfully developed. Structure and properties of MoS2-BC were characterized, it was proved that BC improves microstructure and morphology, electronic conductivity, electrode stability and electrocatalytic properties of MoS2. Attributing to these impressive features, the detection signal of hyperin was significantly amplified by the MoS2-BC modified glass carbon electrode (GCE) in detection range of 0.01-21 µΜ with detection limit (LOD) of 5 nM. It was worth mentioning that the MoS2-BC modified screen-printed electrode (SPE) performs hyperin detection in range of 100 nM - 3 µM with LOD 50 nM (S/N = 3). The practicability of the proposed method confirmed that the portable, on-site, low-cost, and outdoor detection of hyperin was feasible and practical in comparison with traditional both electrochemical sensing and HPLC methods.

Green synthesis of kudzu vine biochar decorated graphene-like MoSe2 with the oxidase-like activity as intelligent nanozyme sensing platform for hesperetin.

It is an urgent need to exploit a potentially green, cost efficient and eco-friendly strategy for the utilization of waste kudzu vine. We developed a one-step green preparation of kudzu vine biochar (BC) decorated graphene-like molybdenum selenide (MoSe2) with the oxidase-like activity as intelligent nanozyme sensing platform for voltametric detection of hesperetin (HP) in orange peel using the in-situ hydrothermal synthesis method. The structure and properties of MoSe2-BC was characterized, and found that BC significantly improved electrochemical cycle stability, electronic conductivity, electrochemical active area, and electrocatalytic activity of MoSe2. The oxidase-like activity of MoSe2-BC was confirmed by the oxidization of the colorless substrate 3,3',5,5'-tetramethylbenzidine (TMB) to form blue products and the change of absorbance intensity of UV-vis absorption spectra. The MoSe2-BC exhibited excellent electrochemical sensing performance for the detection of HP in wide linear ranges from 10 nM to 9.5 µM with a low limit of detection of 2 nM using differential pulse voltammetric method. An emerging machine learning technique is used to realize the intelligent sensing of HP, and the performance evaluation of regression analysis was selected to evaluate this technique. This work will provide a guidance for the preparation and application of biochar decorated graphene-like nanomaterials with the oxidase-like activity and the development of intelligent nanozyme sensing platform.

Crystalline lens thickness change is associated with axial length elongation and myopia progression in orthokeratology.

AIMS: Considering individual variability in regards to the effects of orthokeratology (ortho-k) on myopia progression and controversies regarding the precise underlying mechanism, the aim of this study was to investigate several ocular measurements associated with axial length (AL) growth in children wearing ortho-k lenses. METHODS: In this retrospective chart review, medical records of 53 Chinese children who wore ortho-k lenses over the course of 12 months were reviewed. Baseline variables included age at initiation of ortho-k wear, refractive error (spherical equivalent, SE), central corneal thickness (CCT), and flat and steep keratometry of corneal principal meridians. The change of anterior chamber depth (ACD) and the change of crystalline lens thickness (CLT) between baseline and the 12-month follow-up were also analyzed. The contributions of all analyzed variables to AL change were assessed using univariate and multivariate regression analyses. RESULTS: Initially, the results of paired t-test showed that CLT and AL were significantly increased after 12 months of ortho-k wear compared with that at baseline (P = 0.001 and < 0.001). The ACD did not change significantly after 12 months compared with that at baseline (P = 0.491). Subsequently, univariate analyses showed that a reduced rate of AL elongation was found in children who were older age at initiation of ortho-k wear (P = 0.028), had greater SE (higher degree of myopia) at baseline (p = 0.006), had thicker CCT at baseline (P = 0.04), and had greater increase of CLT (P = 0.001) in 12 months. At last, only greater SE (higher degree of myopia) and greater increase of CLT were associated with smaller increases of AL in multivariable analyses, (P = 0.003 and 0.001). CONCLUSIONS: Both CLT and AL were significantly increased in children with overnight ortho-k wear after 12 months of follow-up. Greater baseline SE and greater increase of CLT were associated with less increase in AL during ortho-k wear in children with myopia.