Substrate Pretreatment Research Articles

Surface modifications of zirconia with plasma pretreatment and polydopamine coating to enhance the bond strength and durability between zirconia and titanium.

The aim of this study was to assess the shear bond strength and durability between plasma-pretreated and polydopamine (PDA)-coated zirconia and titanium. Four groups were prepared according to the different surface treatments (untreated ZrO2, plasma-pretreated ZrO2, PDA-coated ZrO2, and plasma-pretreated and PDA-coated ZrO2 (PP+PDA-ZrO2). The surface topography and roughness, contact angle, and elemental analysis of the coatings of the four groups were investigated, and the bond strength and durability of the specimens were evaluated based on shear bond strength and thermocycle tests. Physical and chemical characterization results confirmed that PDA coatings can be successfully formed on zirconia substrates. The roughness and hydrophilicity were significantly higher in the PP+PDA-ZrO2 group, which demonstrated better shear bond strength and durability between zirconia and titanium. The plasma pretreatment of zirconia substrates can enhance the stability of the PDA coating layer, and hybrid surface modifications can provide several bonding advantages for clinical use.

Cane Pretreatment by Deep Eutectic Solvents to Increase its Reactivity During Enzymatic Hydrolysis with Cellulases

Cane was pretreated with a number of deep eutectic solvents (DESs) based on choline chloride (ChCl) as a hydrogen bond acceptor. Among hydrogen bond donors, lactic (LA) and oxalic (OA) acids were the most effective. Substrate pretreatment conditions (ratio of DES-components, temperature and exposure time) were optimized, which resulted in the highest yield of reducing sugars (RS) and glucose during subsequent enzymatic hydrolysis with cellulase preparation based on Penicillium verruculosum. It was established that in the case of a mixture of ChCl with LA (the molar ratio of components was 1 : 5) pretreatment should be carried out at 80°C for 24 hours, and in the case of a mixture of ChCl with OA (1 : 1), optimal conditions were 80°C and 6 hours. The degree of conversion of the pretreated substrate after 48 hours of hydrolysis in the presence of the enzyme preparation (EP) B537 was 80 and 86% by absolutely dry substances for selected mixtures of ChCl/LA and ChCl/OA, respectively.

Effect of NaOH-catalyzed organosolv pretreatment on the co-production of ethanol and xylose from poplar

NaOH-catalyzed organosolv pretreatment was proposed to degrade lignin, retain cellulose and hemicellulose in poplar, and the pretreated substrates was used to produce ethanol and xylose simultaneously. After the organosolv pretreatment conducted at 205 ºC for 20 min with 1.2% NaOH, the optimal ethanol concentration and xylose yield reached 30.1 g/L and 10.3 g/100 g raw material after 48 h, respectively, and the xylose yield was positively correlated with the ethanol concentration (R2 =0.934). The alteration in chemical composition and structure enhanced the ethanol concentration and xylose yield, which was revealed by Scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform-infrared spectrum (FT-IR), Thermogravimetric (TG), and correlation analysis. In addition, their capacity for generating ethanol and xylose during three fermentation processes was comprehensively compared. The results indicated that SSF was beneficial to improve ethanol concentration, and SHF was in favour of enhancing xylose and ethanol yields to 95.4% and 85.3% based on retained xylan after pretreatment and the fermentable glucose, respectively. The NaOH enhanced organosolv pretreatment exhibited excellent performance in converting poplar into energy and chemicals, which presented a new idea for biomass refining.

Influence of 3-aminopropyltriethoxysilane/tetraethylorthosilicate mixture pretreatment on the microstructure and corrosion resistance of zeolite coating

ABSTRACT The influence of silane pretreatment with five different volume ratios (100/0, 75/25, 50/50, 25/75, and 0/100) of 3-aminopropyltriethoxysilane (APTES)/tetraethylorthosilicate (TEOS) on microstructure and corrosion resistance of the hydrothermal synthesized zeolite coatings on the H13 steel substrates was investigated. The surface of the zeolite coatings on the 100/0, 75/25, and 50/50 mixture of the APTES/TEOS pretreated substrates was composed of intergrown rectangular particles. Additionally, pores were observed. A 25/75 mixture of APTES/TEOS pretreatment smoothed the edges and angles of zeolite particles with gel-like materials filled in the pores. In pure TEOS pretreatment, microcracks, and much gel-like materials were observed on the zeolite coating. The electrochemical test revealed that the zeolite coating on a 50/50 mixture of the APTES/TEOS pretreated substrate exhibited the highest corrosion resistance in 3.5 wt-% NaCl solution. This was because a 50/50 mixture of APTES/TEOS pretreatment advantageously promoted development of a dense and thick gel layer, which enhanced the intergrowth of zeolite particles.

Cane Pretreatment by Deep Eutetic Solvents to Increase its Reactivity During Enzymatic Hydrolysis with Cellulases

Cane was pretreated with a number of deep eutectic solvents (DES) based on choline chloride (ChCl) as a hydrogen bond acceptor; among hydrogen bond donors, lactic and oxalic acids (LacA and OxA, respectively) were the most effective. Substrate pretreatment conditions (ratio of DES-components, temperature and exposure time) were optimized, leading to the highest yield of reducing sugars (RS) and glucose during subsequent enzymatic hydrolysis with cellulase preparation based on Penicillium verruculosum. It was been established that in the case of a mixture of ChCl with LacA (the molar ratio of components is 1 : 5) pretreatment should be carried out at 80°С for 24 h, and in the case of a mixture of ChCl with OxA (1 : 1) – at 80°С for 6 hours. The degree of conversion of the pretreated substrate after 48 hours of hydrolysis in the presence of the enzyme preparation (EP) B537 was 80 and 86% by absolutely dry substances for selected mixtures of ChCl/LacA and ChCl/OxA, respectively.

Production of the Cellulase Enzyme System by Locally Isolated Trichoderma and Aspergillus Species Cultivated on Banana Pseudostem during Solid-State Fermentation

The production cost of cellulases is regarded as a limiting factor in the cellulosic ethanol production chain. Trichoderma and Aspergillus species were used to produce cellulases through solid-state fermentation (SSF) utilizing banana pseudostem (BPS) as a carbon source. The production of cellulases was investigated at various substrate moisture contents (65–80%), incubation temperatures (30–40 °C), substrate pre-treatment methods (3% w/v NaOH, 5% v/v H2SO4, and water), and with different co-culturing of microorganisms. Trichoderma longibrachiatum LMLSAUL 14-1 produced the maximum total cellulase (75 FPU/g d.s), endoglucanase (11.35 U/g d.s), and β-glucosidase (235.83 U/g d.s) activities at a 75% moisture content of the untreated BPS at 30 °C in static culture. Pre-treatment of BPS improved the production of specific enzymes. Aspergillus fumigatus LMLPS 13-4 produced more β-glucosidase (259.8 U/g d.s) when grown on acid-pre-treated BPS, whereas T. harzianum LMLBP07 13-5 produced the highest β-glucosidase activity (319.5 U/g d.s) on alkali-pre-treated BPS. Co-culturing of T. harzianum LMLBP07 13-5 and A. fumigatus LMLPS 13-4 improved the production of endoglucanase. These results suggest that banana pseudostem, a waste product of the banana industry, could be a potentially cheaper and abundant substrate for the production of the cellulase enzymes.

Transition Metal β-Diketonate Adhesion Promoters in Epoxy-Anhydride Resin.

Epoxy to copper adhesion supports the reliability of numerous structures in electronic packaging. Compared to substrate pre-treatment, processing and cost considerations are in favor of adhesion promoters loaded in epoxy formulations. In this work, first row transition metal β-diketonates present such a compelling case when added in epoxy/anhydride resins: over 30% (before moisture aging) and 50% (after moisture aging) enhancement in lap shear strength are found using Co(II) and Ni(II) hexafluoroacetylacetonate. From extensive X-ray photoelectron spectroscopy (XPS) analyses on the adhesively failed sample surfaces, increased population of oxygen-containing functional groups, especially esters, is linked to the adhesion improvement. Assisted by XPS depth profile on the fractured epoxy side and in situ Fourier-transform infrared spectroscopy (FTIR), the previously discovered latent cure characteristics endowed by the metal chelates interacting with phosphine catalysts are regarded pivotal for pacing the anhydride consumption and allowing interfacial esterification reactions to occur. Further examinations on the XPS binding energy shifts and dielectric properties of the doped epoxy also reveal metal-polymer coordination that contribute to the adhesion and moisture resistance properties. These findings should stimulate future research of functional additives targeting at cure kinetics control and polar group coordination ideas for more robust epoxy-Cu joints.

Effect of pretreatment severity on the inhibitory behaviors of larch lignins in enzymatic hydrolysis

To explore the underlying reasons for the decreased enzymatic hydrolysis yields of the acid pretreated softwood under the higher pretreatment severity, the residual bulk lignins, as one type lignin fraction with stronger inhibition, were isolated from larch (softwood) pretreated with different pretreatment severity in this study. The lignin structure changes during the pretreatment were comprehensively investigated by nuclear magnetic resonance (NMR) analysis. The larch lignins addition decreased the enzymatic hydrolysis of Avicel from 68.43% to 25.9–39.3%. The pretreatment intensified the inhibition of isolated lignins on enzymatic hydrolysis of Avicel. Furthermore, quartz crystal microbalance (QCM) analysis was applied to investigate the interaction between enzyme and lignins, distinguishing the reversible and irreversible enzyme adsorption. It demonstrated that the obviously higher irreversible adsorption of enzyme was observed on lignins from pretreated substrates with the higher severity. Additionally, the correlation between structure and inhibition of residual lignins in the enzymatic hydrolysis was then investigated with Pearson’s correlation heatmap. The findings can be used to develop theoretical guidelines for alleviating the residual lignin inhibition in the enzymatic hydrolysis of acidic pretreated softwood.

Distinct lignocellulolytic enzymes produced by Trichoderma harzianum in response to different pretreated substrates

In order to optimize the composition of enzyme cocktail for improving the hydrolytic efficiency of lignocellulose, different substrates were tested as inducers for producing lignocellulolytic enzymes by Trichoderma harzianum EM0925 in this study. As results, ultrafine grinding or steam explosion pretreated substrates can induce T. harzianum EM0925 to secret holo lignocellulolytic enzymes; acid treated substrate can induce cellobiohydrolase; while alkali or sodium chlorite treated substrates can induce β-xylosidase specifically. Furthermore, the combination of enzyme cocktails with different hydrolysis characteristics can further improve the hydrolysis efficiency, since 100% yields of glucose and xylose were obtained simultaneously from ultrafine grinding treated corn stover at low enzyme dosage (1.2 mg proteins/g substrate). This study for the first time demonstrated an effective solution that specific-pretreated substrates can be used as inducers for specific enzyme production by T. harzianum, which provided new idea and potential strategy for the construction of highly-efficient lignocellulolytic enzyme cocktails.

Thermophilic biohydrogen production from optimized enzymatic pretreatment of palm oil mill effluent via box-behnken design

The demand for energy is increasing continuously due to the vast developments in many ways of life. Palm oil mill effluent (POME) seems to be a good carbon feedstock for hydrogen generation in fermentation processes. A biological pretreatment was applied to degrade the lignocellulose biomass in the anaerobic digestion process and improve the bioenergy production yield; one of the techniques is to use enzymes. In this study, enzymatic pretreatment was applied to POME to determine the optimum process parameters for producing reducing sugars (RS) to be used as a substrate in biohydrogen production. The Box-Behnken design (BBD) was used to construct an experiment to optimize the pretreatment variables, such as reaction time (h), enzyme concentration (% w/v), and pH. The optimum experimental conditions were found to be 12 hr of reaction time, an enzyme concentration of 3.76% w/v, and pH 5. The result showed that POME treated with the optimal enzymatic pretreatment increased the RS content by 182%. Next, thermophilic biohydrogen production using a pretreated substrate was carried out at a temperature of 55 °C, mixing speed of 150 rpm, Chemical Oxygen Demand (COD) concentration of 29,100 mg/L, seed content of 18.2%, and initial pH 7.14. The biohydrogen production potential (Hmax) was significantly increased by 145% (177 mL H2/g reducing sugar) by using enzymatically pretreated POME as a substrate. This result indicated that the recovery of RS from recalcitrant POME via enzymatic pretreatment could enhance biohydrogen production. Hence, it is a useful proposal for further application in bioenergy conversion from organic waste.

Delignification of Halophyte Atriplex crassifolia by Green Recyclable Deep Eutectic Solvents for Enhanced Production of Biogas

Deep eutectic solvents (DESs) have upgraded the practices of valorizing lignocellulosic feedstock by lessening biomass recalcitrance through delignification in precise and economical manner. In this study, the influence of a series of deep eutectic mixtures was evaluated on the halophyte Atriplex crassifolia for achieving elevated biogas production. Initially, the biomass was pretreated via several DESs with varying hydrogen bond donors (HBDs) including carboxylic acids, amine/amide, and polyols/glycols. DES composed of choline chloride (ChCl) and lactic acid (LA) evidenced as the most effective solvent in achieving high lignin removal rates and was further optimized by evaluating the parameters of molar ratio of DES components, solid-to-liquid ratio, and solvent addition. A maximum delignification value of 89.5% was achieved by 15% diluted ChCl: LA (1:2) DES at a biomass loading of 1:15. The solubilization rate of diluted ChCl: LA was also raised up to 38%. FT-IR analysis revealed significant lignin elimination from ChCl: LA pretreated substrates. Moreover, ≥88% of ChCl: LA DES was recovered after up to three pretreatment cycles, retaining ≥85% delignification efficiency. Fresh DES-pretreated Atriplex crassifolia recorded 32.2 mL/g of biogas production yield due to increased cellulosic content. The findings validated Atriplex crassifolia as an efficient feedstock for biogas production and confirmed the affectivity of ChCl: LA pretreatment in eliminating the lignin barrier, ultimately making cellulosic sugars readily biodegradable and highly accessible for anaerobic microorganisms.

Effect of substrate pretreatments on the structure and properties of AlTiN coatings deposited on TiCN-based cermets

Four different pretreatments (mirror polishing, grinding, sandblasting and acid washing) were performed on TiCN-based cermets substrates. Subsequently, AlTiN coatings were deposited on the four differently pretreated substrates by means of arc ion plating. The microstructure of AlTiN coatings were studied by scanning electron microscope and X-ray diffractometer. The results showed that the AlTiN coatings on differently pretreated substrates exhibited columnar structure with (200) preferred orientation. The columnar crystal of coatings coarsened with the increase of substrate surface roughness under the four pretreatments, and the thickness of the coatings increased. Scratch test showed that the adhesion strength of the AlTiN coating on the pickled substrate increased by 46.8% in comparison with that on the polished substrate. Wear test showed that the average friction coefficient of AlTiN coatings increased gradually with the increase of substrate surface roughness under the four substrate pretreatments. The AlTiN coating on the pickled substrate had the largest grain size and many voids. Therefore, the hardness was low and the wear resistance was poor. The AlTiN coating on the sandblasted substrate had the smallest grain size, and accordingly had high hardness and the best wear resistance.

Osteogenic and anti-inflammatory effects of SLA titanium substrates doped with chitosan-stabilized selenium nanoparticles via a covalent coupling strategy

Osseointegration is a prerequisite for the function of dental implants, and macrophage-dominated immune responses triggered by implantation determine the outcome of ultimate bone healing mediated by osteogenic cells. The present study aimed to develop a modified titanium (Ti) surface by covalently immobilizing chitosan-stabilized selenium nanoparticles (CS-SeNPs) to sandblasted, large grit, and acid-etched (SLA) Ti substrates and further explore its surface characteristics as well as osteogenic and anti-inflammatory activities in vitro. CS-SeNPs were successfully prepared by chemical synthesis and characterized their morphology, elemental composition, particle size, and Zeta potential. Subsequently, three different concentrations of CS-SeNPs were loaded to SLA Ti substrates (Ti-Se1, Ti-Se5, and Ti-Se10) using a covalent coupling strategy, and the SLA Ti surface (Ti-SLA) was used as a control. Scanning electron microscopy images revealed different amounts of CS-SeNPs, and the roughness and wettability of Ti surfaces were less susceptible to Ti substrate pretreatment and CS-SeNP immobilization. Besides, X-ray photoelectron spectroscopy analysis showed that CS-SeNPs were successfully anchored to Ti surfaces. The results of in vitro study showed that the four as-prepared Ti surfaces exhibited good biocompatibility, with Ti-Se1 and Ti-Se5 groups showing enhanced adhesion and differentiation of MC3T3-E1 cells compared with the Ti-SLA group. In addition, Ti-Se1, Ti-Se5, and Ti-Se10 surfaces modulated the secretion of pro-/anti-inflammatory cytokines by inhibiting the nuclear factor kappa B pathway in Raw 264.7 cells. In conclusion, doping SLA Ti substrates with a modest amount of CS-SeNPs (1–5 mM) may be a promising strategy to improve the osteogenic and anti-inflammatory activities of Ti implants.

Effects of enzymatic hydrolysis and physicochemical properties of lignocellulose waste through different choline based deep eutectic solvents (DESs) pretreatment

DESs are promising green solvents in lignocellulose pretreatment. In this work, four choline chloride based DESs were synthesized and their physicochemical properties were evaluated. Herbaceous lignocellulose (wheat straw, sorghum straw) and woody lignocellulose biomass (poplar wood, pine wood) were selected as pretreated substrates. In order to reveal the mechanism that pretreatment can improve the efficiency of enzymatic hydrolysis, the pretreated lignocellulose and lignin were analyzed. SEM, FT-IR and XRD characterization revealed the microstructural changes of pretreated lignocellulose, including the increase of surface roughness and pore erosion, changes of polysaccharide/lignin chemical groups, the increase of CrI. The efficient delignification increased the accessibility of enzyme to cellulose, the lignin content negatively affected enzymatic hydrolysis conversion. Furthermore, GPC analysis showed that the polydispersity of sulfonated lignin was reduced after pretreatment, lignin had more homogeneous molecular structures. The degree of unsaturation was calculated according to the elemental composition of sorghum straw and lignin. The unsaturation of pretreated sorghum straw decreased, that may be due to the removal of partial lignin. The elemental composition of acid insoluble lignin (separated from sorghum straw) reflects the increase of unsaturation of lignin after pretreatment.

Distinctive Effects of Surface Roughness and Ions Release on the Bacterial Adhesion and Inactivation of Textured Copper Oxide Surfaces

In this manuscript, we studied the effect of additive manufacturing pretreatment on bacterial adhesion and inactivation on copper-based interfaces. Sandblasting, mirror polishing and Surface Mechanical Attrition Treatment (SMAT) at high or low energies have been employed to modify the substrate’s (316L stainless steel) roughness. The pretreated substrates were coated with thin copper films using magnetron sputtering. The thin copper films’ composition and antibacterial activities were first optimized by being deposited on an Si wafer. We showed that the surface roughness profile influenced bacterial adhesion in the dark. Bacterial inactivation was monitored under indoor light. Stereomicroscopy imaging showed live/dead bacterial cells on the coated substrates. Scanning electron microscopy (SEM) showed homogeneous coating growths of copper with a columnar texture. The chemical composition of the deposited Cu thin films was carried out by Energy Dispersive X-ray Spectroscopy (EDX) and showed a uniform distribution of copper and oxygen, revealing the formation of copper oxides (CuxO). The oxygen content of the sputtered films varied from 7.8 to 25%, justifying the semi-conductor behavior of the thin films under indoor light. The crystallographic structure of the sputtered thin films was investigated using X-ray diffraction (XRD), showing the cubic Cu peaks and characteristic peaks of Cu2O. The Cu peaks at 2θ values of 43.28°, 50.40° and 74.81° were attributed to the (111), (200) and (220) planes, respectively. The use of genetically modified bacteria (without porins) allowed the rationalization of the predominant effect of the extracellular bacterial inactivation compared to that of intracellular bacterial inactivation through ion release and diffusion.

Adhesion of batch hot-dip galvanized components

Structural bonding of batch hot-dip galvanized components poses a particular challenge against the background of the build-up of the zinc coating in the form of different zinc-iron phases. As part of a research project, parameters influencing the zinc coating, the pre-treatment of the zinc substrate, and the adhesive were investigated with regard to the load-bearing capacity of a bonded joint. The variation of the zinc coatings was achieved by using four different steel grades in combination with four batch galvanizing processes. Therefore, small-scale, thick shear tensile specimens were uniformly fabricated, galvanized, bonded in pairs, and mechanically tested. A second series of tests was aimed at the feasibility of an adhesive bond of batch galvanized, medium-scale components under realistic boundary conditions. The test specimens were produced by varying the surface preparation and the adhesive and tested mechanically to shear failure. The results of both test series show that zinc-coated components can be adhesively bonded well and reliably, and, by this, a high load-bearing capacity can be achieved in the bonded joint. The small-scale tests clearly show that the type of zinc coating and its structure obviously have a significant influence on the load-bearing capacity. In summary, it can be stated that the relevant material and process-related influences on the shear load-bearing behavior of bonded joints of batch hot-dip galvanized components were demonstrated by means of the two test series, and the basis for implementing such joints on real load-bearing structures was laid. The presented procedure (small-scale tests and component tests) can be used as a suggestion for a later application in practice.

Study of Single and Multipass f-rGO Inkjet-Printed Structures with Various Concentrations: Electrical and Thermal Evaluation.

Reduced graphene oxide (rGO) is a derivative of graphene, which has been widely used as the conductive pigment of many water-based inks and is recognized as one of the most promising graphene-based materials for large-scale and low-cost production processes. In this work, we evaluate a custom functionalised reduced graphene oxide ink (f-rGO) via inkjet-printing technology. Test line structures were designed and fabricated by the inkjet printing process using the f-rGO ink on a pretreated polyimide substrate. For the electrical characterisation of these devices, two-point (2P) and four-point (4P) probe measurements were implemented. The results showed a major effect of the number of printed passes on the resulting resistance for all ink concentrations in both 2P and 4P cases. Interesting results can be extracted by comparing the obtained multipass resistance values that results to similar effective concentration with less passes. These measurements can provide the ground to grasp the variation in resistance values due to the different ink concentrations, and printing passes and can provide a useful guide in achieving specific resistance values with adequate precision. Accompanying topography measurements have been conducted with white-light interferometry. Furthermore, thermal characterisation was carried out to evaluate the operation of the devices as temperature sensors and heaters. It has been found that ink concentration and printing passes directly influence the performance of both the temperature sensors and heaters.

Solid Ink Laser Patterning for High‐Resolution Information Labels with Supervised Learning Readout

AbstractTagging, tracking, or validation of products are often facilitated by inkjet‐printed optical information labels. However, this requires thorough substrate pretreatment, ink optimization, and often lacks in printing precision/resolution. Herein, a printing method based on laser‐driven deposition of solid polymer ink that allows for printing on various substrates without pretreatment is demonstrated. Since the deposition process has a precision of <1 µm, it can introduce the concept of sub‐positions with overlapping spots. This enables high‐resolution fluorescent labels with comparable spot‐to‐spot distance of down to 15 µm (444,444 spots cm−2) and rapid machine learning‐supported readout based on low‐resolution fluorescence imaging. Furthermore, the defined thickness of the printed polymer ink spots can be used to fabricate multi‐channel information labels. Additional information can be stored in different fluorescence channels or in a hidden topography channel of the label that is independent of the fluorescence.

Bioactive Synthetic Polymer-Based Polyelectrolyte LbL Coating Assembly on Surface Treated AZ31-Mg Alloys

Polyelectrolyte layer-by-layer (LbL) films on pretreated Mg containing 3 wt.% Al and 1 wt.% Zn (MgAZ31) alloy surfaces were prepared under physiological conditions offering improved bioresponse and corrosive protection. Pretreatments of the model MgAZ31 substrate surfaces were performed by alkaline and fluoride coating methods. The anti-corrosion and cytocompatibility behavior of pretreated substrates were evaluated. The LbL film assembly consisted of an initial layer of polyethyleneimine (PEI), followed by alternate layers of poly (lactic-co-glycolic acid) (PLGA) and poly (allylamine hydrochloride) (PAH), which self-arrange via electrostatic interactions on the pretreated MgAZ31 alloy substrate surface. The physicochemical characterization, surface morphologies, and microstructures of the LbL films were investigated using Fourier-transformed infrared spectroscopy (FTIR), atomic force microscopy (AFM), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The in vitro stability studies related to the LbL coatings confirmed that the surface treatments are imperative to achieve the lasting stability of PLGA/PAH layers. Electrochemical impedance spectroscopy measurements demonstrated that pretreated and LbL multilayered coated substrates enhanced the corrosion resistance of the bare MgAZ31 alloy. Cytocompatibility studies using human mesenchymal stem cells seeded directly over the substrates showed that the pretreated and LbL-generated surfaces were more cytocompatible, displaying reduced cytotoxicity than the bare MgAZ31. The release of bovine serum albumin protein from the LbL films was also studied. The initial data presented cooperatively demonstrate the promise of creating LbL layers on Mg-related bioresorbable scaffolds to obtain improved surface bio-related activity.

Development of boron doped diamond electrodes material for heavy metal ion sensor with high sensitivity and durability

We report on the optimized substrate pretreatment and deposition process conditions for boron-doped diamond (BDD) electrodes fabricated by hot-filament chemical vapor deposition (HFCVD). The optimized BDD electrode with a doping concentration of 8000 ppm showed high accuracy and precision in detecting Cd(II), Pb(II), and Cu(II) ions. In addition, this demonstrates excellent selectivity against external metal ions under the optimized stripping voltammetry measurement conditions. The detection limits of the target ions of Cd(II), Pb(II), and Cu(II) were 0.55 (±0.05), 0.43 (±0.04), and 0.74 (±0.06) μg/L (S/N = 3), respectively. In real samples spiked with 100 μg/L Cd(II), Pb(II), and Cu(II), both the accuracy and precision of the BDD electrode were within 5%; the interference with organic matter was also negligible. The excellent selectivity and long-term stability indicate that the BDD electrode developed in this study are potentially useful for online water environment monitoring systems.