Exploring novel function of Gpx5 antioxidant activity: Assisting epididymal cells secrete functional extracellular vesicles.

Glutathione peroxisomal-5 (Gpx5) promotes the elimination of H2O2 or organic hydrogen peroxide, and plays an important role in the physiological process of resistance to oxidative stress (OS). To directly and better understand the protection of Gpx5 against OS in epididymal cells and sperm, we studied its mechanism of antioxidant protection from multiple aspects. To more directly investigate the role of Gpx5 in combating oxidative damage, we started with epididymal tissue morphology and Gpx5 expression profiles in combination with the mouse epididymal epithelial cell line PC1 (proximal caput 1) expressing recombinant Gpx5. The Gpx5 is highly expressed in adult male epididymal caput, and its protein signal can be detected in the sperm of the whole epididymis. Gpx5 has been shown to alleviate OS damage induced by 3-Nitropropionic Acid (3-NPA), including enhancing antioxidant activity, reducing mitochondrial damage, and suppressing cell apoptosis. Gpx5 reduces OS damage in PC1 and maintains the well-functioning extracellular vesicles (EVs) secreted by PC1, and the additional epididymal EVs play a role in the response of sperm to OS damage, including reducing plasma membrane oxidation and death, and increasing sperm motility and sperm-egg binding ability. Our study suggests that GPX5 plays an important role as an antioxidant in the antioxidant processes of epididymal cells and sperm, including plasma membrane oxidation, mitochondrial oxidation, apoptosis, sperm motility, and sperm-egg binding ability.

Maslinic acid supplementation prevents di(2-ethylhexyl) phthalate-induced apoptosis via PRDX6 in peritubular myoid cells of Chinese forest musk deer.

Chinese forest musk deer (FMD), an endangered species, have exhibited low reproductive rates even in captivity due to stress conditions. Investigation revealed the presence of di(2-ethylhexyl) phthalate (DEHP), an environmental endocrine disruptor, in the serum and skin of captive FMDs. Feeding FMDs with maslinic acid (MA) has been observed to alleviate the stress response and improve reproductive rates, although the precise molecular mechanisms remain unclear. Therefore, this study aims to investigate the molecular mechanisms underlying the alleviation of DEHP-induced oxidative stress and cell apoptosis in primary peritubular myoid cells (PMCs) through MA intake. Primary PMCs were isolated and exposed to DEHP in vitro. The results demonstrated that DEHP significantly suppressed antioxidant levels and promoted cell apoptosis in primary PMCs. Moreover, interfering with the expression of PRDX6 was found to induce excessive reactive oxygen species (ROS) production and cell apoptosis in primary PMCs. Supplementation with MA significantly upregulated the expression of PRDX6, thereby attenuating DEHP-induced oxidative stress and cell apoptosis in primary PMCs. These findings provide a theoretical foundation for mitigating stress levels and enhancing reproductive capacity of in captive FMDs.

Exosomes from porcine serum as endogenous additive maintain function of boar sperm during liquid preservation at 17 °C in vitro.

The supplementation of sperm culture media with serum is quite common, and improves both sperm survival and motility. However, the link between serum and sperm remains poorly understood. The present study is the first investigation of the effects on sperm quality and function of endogenous porcine serum exosomes in medium used for culturing boar sperm. Scanning electron microscopy (SEM) confirmed that serum-derived exosomes from both castrated boars (cbsExos) and sows (ssExos) exhibited typical nanostructural morphology and expressed CD63, CD9, and Alix, as shown by Western blotting. At 17 °C, the progressive motility and membrane integrity of sperm were significantly increased after incubation of fresh boar semen for 7 days with cbsExos-4 (8 × 1010 particles/mL) or ssExos-16 (32 × 1010 particles/mL). Moreover, cbsExos-4 and ssExos-16 were found to be effective sperm additives, improving mitochondrial transmembrane potential (ΔΨm) and adenosine triphosphate (ATP) content, total antioxidant activity (T-AOC), superoxide dismutase (SOD) activity, and glutathione peroxidase (GPx) activity while reducing reactive oxygen species (ROS) levels, and malondialdehyde (MDA) content following preservation at 17 °C after a 5-day incubation. Both fluorescence and SEM showed that the serum exosomes bound directly to the sperm membrane, suggesting an interaction that could influence sperm-zona pellucida binding. Overall, this study provides new insights into the potential benefits of adding cbsExos and ssExos to enhance the quality of boar sperm during ambient temperature preservation, which may lead to advancements in sperm preservation strategies.

Inversely engineered biomimetic flexible network scaffolds for soft tissue regeneration.

Graft-host mechanical mismatch has been a longstanding issue in clinical applications of synthetic scaffolds for soft tissue regeneration. Although numerous efforts have been devoted to resolve this grand challenge, the regenerative performance of existing synthetic scaffolds remains limited by slow tissue growth (comparing to autograft) and mechanical failures. We demonstrate a class of rationally designed flexible network scaffolds that can precisely replicate nonlinear mechanical responses of soft tissues and enhance tissue regeneration via reduced graft-host mechanical mismatch. Such flexible network scaffold includes a tubular network frame containing inversely engineered curved microstructures to produce desired mechanical properties, with an electrospun ultrathin film wrapped around the network to offer a proper microenvironment for cell growth. Using rat models with sciatic nerve defects or Achilles tendon injuries, our network scaffolds show regenerative performances evidently superior to that of clinically approved electrospun conduit scaffolds and achieve similar outcomes to autologous nerve transplantation in prevention of target organ atrophy and recovery of static sciatic index.

Genetic and histological relationship between pheromone-secreting tissues of the musk gland and skin of juvenile Chinese forest musk deer (Moschus berezovskii Flerov, 1929). / 中国幼年林麝（Moschus berezovskii Flerov, 1929ï¼‰é¦™è ºå’Œçš®è‚¤åˆ†æ³Œä¿¡æ¯ç´ çš„é—ä¼ å’Œç»„ç»‡å­¦å ³ç³».

BACKGROUND: The musk glands of adult male Chinese forest musk deer (Moschus berezovskii Flerov, 1929) (FMD), which are considered as special skin glands, secrete a mixture of sebum, lipids, and proteins into the musk pod. Together, these components form musk, which plays an important role in attracting females during the breeding season. However, the relationship between the musk glands and skin of Chinese FMD remains undiscovered. Here, the musk gland and skin of Chinese FMD were examined using histological analysis and RNA sequencing (RNA-seq), and the expression of key regulatory genes was evaluated to determine whether the musk gland is derived from the skin. METHODS: A comparative analysis of musk gland anatomy between juvenile and adult Chinese FMD was conducted. Then, based on the anatomical structure of the musk gland, skin tissues from the abdomen and back as well as musk gland tissues were obtained from three juvenile FMD. These tissues were used for RNA-seq, hematoxylin-eosin (HE) staining, immunohistochemistry (IHC), western blot (WB), and quantitative real-time polymerase chain reaction (qRT-PCR) experiments. RESULTS: Anatomical analysis showed that only adult male FMD had a complete glandular organ and musk pod, while juvenile FMD did not have any well-developed musk pods. Transcriptomic data revealed that 88.24% of genes were co-expressed in the skin and musk gland tissues. Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathway analysis found that the genes co-expressed in the abdomen skin, back skin, and musk gland were enriched in biological development, endocrine system, lipid metabolism, and other pathways. Gene Ontology (GO) enrichment analysis indicated that the genes expressed in these tissues were enriched in biological processes such as multicellular development and cell division. Moreover, the Metascape predictive analysis tool demonstrated that genes expressed in musk glands were skin tissue-specific. qRT-PCR and WB revealed that sex-determining region Y-box protein 9 (Sox9),Caveolin-1 (Cav-1), andandrogen receptor (AR) were expressed in all three tissues, although the expression levels differed among the tissues. According to the IHC results, Sox9 and AR were expressed in the nuclei of sebaceous gland, hair follicle, and musk gland cells, whereas Cav-1 was expressed in the cell membrane. CONCLUSIONS: The musk gland of Chinese FMD may be a derivative of skin tissue, and Sox9, Cav-1, and AR may play significant roles in musk gland development.

Well-defined surface catalytic sites for solar CO2 reduction: heterogenized molecular catalysts and single atom catalysts.

Exciting progress has been made in the area of solar fuel generation by CO2 reduction. New photocatalytic materials containing well-defined surface catalytic sites have emerged in recent years, including heterogenized molecular catalysts and single atom catalysts. This Feature Article summarizes our recent research in this area, together with brief discussions of relevant literature. In our effort to obtain heterogenized molecular catalysts, a diimine-tricarbonyl Re(I) complex and a tetraaza macrocyclic Co(III) compound were covalently attached to different surfaces, and the effects of ligand derivatization and surface characteristics on their structures and photocatalytic activities were investigated. Single atom catalysts combine the advantages of homogeneous and heterogeneous catalysis. A single-site cobalt catalyst was prepared on graphitic carbon nitride, which demonstrated excellent activity in selective CO2 reduction under visible-light irradiation. Doping carbon nitride with carbon was found to have profound effects on the structure and activity of the single-site cobalt catalyst. Our research achievements are presented to emphasize how spectroscopic techniques, including infrared, UV-visible, electron paramagnetic resonance, and X-ray absorption spectroscopies, could be combined with catalyst synthesis and computation modeling to understand the structures and properties of well-defined surface catalytic sites at the molecular level. This article also highlights challenges and opportunities in the broad context of solar CO2 reduction.

Metformin improves fish sperm quality by regulating glucose uptake capacity during in vitro storage.

A suitable additive for fish sperm storage in vitro is necessary for artificial reproduction. In this study, we evaluated the effects of different concentrations (100, 200, 400, and 800 µmol/L) of metformin (Met) on Schizothorax prenanti and Onychostoma macrolepis sperm under storage in vitro for 72 h. Compared with the control group, 400 µmol/L Met was more effective at improving the quality and fertilization capacity of S. prenanti sperm by increasing the adenosine triphosphate (ATP) content within the sperm. Further study found that Met stabilized the ATP level by enhancing the glucose uptake in S. prenanti sperm, and this effect might be associated with the activation of AMP-activated protein kinase (AMPK) in sperm. In this study, we also found that glucose could be absorbed by the sperm of S. prenanti, which was mainly accumulated in the midpiece of S. prenanti sperm, where mitochondria were located. In addition, Compound C significantly inhibited the beneficial effects of Met on the quality and glucose uptake capacity of S. prenanti sperm by inhibiting AMPK phosphorylation. These results revealed that AMPK played an important role in vitro sperm storage, and Met maintained ATP content and increased the storage time of S. prenanti sperm in vitro for 72 h, possibly due to Met enhanced glucose uptake capacity of sperm by activating AMPK. Similarly, the beneficial effects of Met on S. prenanti sperm were also found in O. macrolepis sperm, suggesting that Met may hold great promise for the practice of storing fish in vitro.

Generally, what matters most to fish sperm is a good storage condition in vitro that can both ensure its high motility after fresh water activation and avoid the damage of the nonactivated state. An appropriate additive can provide suitable storage conditions for sperm. Therefore, a suitable additive of fish sperm is necessary for fish to promote effective artificial reproduction. In this study, we evaluated the effects of different concentrations of metformin (Met) on fish sperm under storage in vitro. Compared with the control group, Met was more effective at improving the quality and fertilization capacity of fish by increasing the adenosine triphosphate (ATP) content within the sperm. Further study found that Met stabilized the ATP level by enhancing the glucose uptake in fish sperm, and this effect might be associated with the activation of AMP-activated protein kinase (AMPK) in sperm. The beneficial effects of Met on fish sperm suggest that Met may hold great promise for the practice of storing fish in future vitro storage.

Programming 3D curved mesosurfaces using microlattice designs.

Cellular microstructures form naturally in many living organisms (e.g., flowers and leaves) to provide vital functions in synthesis, transport of nutrients, and regulation of growth. Although heterogeneous cellular microstructures are believed to play pivotal roles in their three-dimensional (3D) shape formation, programming 3D curved mesosurfaces with cellular designs remains elusive in man-made systems. We report a rational microlattice design that allows transformation of 2D films into programmable 3D curved mesosurfaces through mechanically guided assembly. Analytical modeling and a machine learning-based computational approach serve as the basis for shape programming and determine the heterogeneous 2D microlattice patterns required for target 3D curved surfaces. About 30 geometries are presented, including both regular and biological mesosurfaces. Demonstrations include a conformable cardiac electronic device, a stingray-like dual mode actuator, and a 3D electronic cell scaffold.

A soft microrobot with highly deformable 3D actuators for climbing and transitioning complex surfaces.

The climbing microrobots have attracted growing attention due to their promising applications in exploration and monitoring of complex, unstructured environments. Soft climbing microrobots based on muscle-like actuators could offer excellent flexibility, adaptability, and mechanical robustness. Despite the remarkable progress in this area, the development of soft microrobots capable of climbing on flat/curved surfaces and transitioning between two different surfaces remains elusive, especially in open spaces. In this study, we address these challenges by developing voltage-driven soft small-scale actuators with customized 3D configurations and active stiffness adjusting. Combination of programmed strain distributions in liquid crystal elastomers (LCEs) and buckling-driven 3D assembly, guided by mechanics modeling, allows for voltage-driven, complex 3D-to-3D shape morphing (bending angle > 200°) at millimeter scales (from 1 to 10 mm), which is unachievable previously. These soft actuators enable development of morphable electroadhesive footpads that can conform to different curved surfaces and stiffness-variable smart joints that allow different locomotion gaits in a single microrobot. By integrating such morphable footpads and smart joints with a deformable body, we report a multigait, soft microrobot (length from 6 to 90 mm, and mass from 0.2 to 3 g) capable of climbing on surfaces with diverse shapes (e.g., flat plane, cylinder, wavy surface, wedge-shaped groove, and sphere) and transitioning between two distinct surfaces. We demonstrate that the microrobot could navigate from one surface to another, recording two corresponding ceilings when carrying an integrated microcamera. The developed soft microrobot can also flip over a barrier, survive extreme compression, and climb bamboo and leaf.

Assembly of complex 3D structures and electronics on curved surfaces.

Electronic devices with engineered three-dimensional (3D) architectures are indispensable for frictional-force sensing, wide-field optical imaging, and flow velocity measurement. Recent advances in mechanically guided assembly established deterministic routes to 3D structures in high-performance materials, through controlled rolling/folding/buckling deformations. The resulting 3D structures are, however, mostly formed on planar substrates and cannot be transferred directly onto another curved substrate. Here, we introduce an ordered assembly strategy to allow transformation of 2D thin films into sophisticated 3D structures on diverse curved surfaces. The strategy leverages predefined mechanical loadings that deform curved elastomer substrates into flat/cylindrical configurations, followed by an additional uniaxial/biaxial prestretch to drive buckling-guided assembly. Release of predefined loadings results in an ordered assembly that can be accurately captured by mechanics modeling, as illustrated by dozens of complex 3D structures assembled on curved substrates. Demonstrated applications include tunable dipole antennas, flow sensors inside a tube, and integrated electronic systems capable of conformal integration with the heart.

Comparative transcriptome provides insights into differentially expressed genes between testis and ovary of Onychostoma macrolepis in reproduction period.

The Onychostoma macrolepis (O. macrolepis) is a rare and endangered fishery species inhabiting the river of Qinling Mountains and some flowing freshwaters in China. The declining population of O. macrolepis caused by asynchrony of male and female development prompted us to focus on genetic regulation of its reproduction. In this study, high-throughput RNA-sequencing technology was applied to assemble and annotate the transcriptome of O. macrolepis testis and ovary. The results showed that a number of 338089335 (ovary:163216500, testis:174872835) raw sequences were obtained. After non-redundant analysis, a number of 207826065 (ovary:102334008, testis:105492057) high quality reads were obtained and predicted as unigenes, in which 201,038,682 unigenes were annotated with multiple databases. Taking the ovarian transcriptome as a control, comparative transcriptome analysis showed that 9918 differentially expressed genes (DEGs) up-regulated in the testis and 13,095 DEGs down-regulated. Many DEGs were involved with sex-related GO terms and KEGG pathways, such as oocyte maturation, gonadal development, steroid biosynthesis pathways, MAPK signaling pathway and Wnt signaling pathway. Finally, the expression patterns of 19 unigenes were validated by using quantitative real-time polymerase chain reaction (qRT-PCR). This study illustrates a potential molecular mechanism on the unsynchronized male and female development of the O. macrolepis during the reproduction period in June and provides a theoretical basis for future artificial reproduction.

Submillimeter-scale multimaterial terrestrial robots.

Robots with submillimeter dimensions are of interest for applications that range from tools for minimally invasive surgical procedures in clinical medicine to vehicles for manipulating cells/tissues in biology research. The limited classes of structures and materials that can be used in such robots, however, create challenges in achieving desired performance parameters and modes of operation. Here, we introduce approaches in manufacturing and actuation that address these constraints to enable untethered, terrestrial robots with complex, three-dimensional (3D) geometries and heterogeneous material construction. The manufacturing procedure exploits controlled mechanical buckling to create 3D multimaterial structures in layouts that range from arrays of filaments and origami constructs to biomimetic configurations and others. A balance of forces associated with a one-way shape memory alloy and the elastic resilience of an encapsulating shell provides the basis for reversible deformations of these structures. Modes of locomotion and manipulation span from bending, twisting, and expansion upon global heating to linear/curvilinear crawling, walking, turning, and jumping upon laser-induced local thermal actuation. Photonic structures such as retroreflectors and colorimetric sensing materials support simple forms of wireless monitoring and localization. These collective advances in materials, manufacturing, actuation, and sensing add to a growing body of capabilities in this emerging field of technology.

An Anti-Fatigue Design Strategy for 3D Ribbon-Shaped Flexible Electronics.

Three-dimensional (3D) flexible electronics represent an emerging area of intensive attention in recent years, owing to their broad-ranging applications in wearable electronics, flexible robots, tissue/cell scaffolds, among others. The widely adopted 3D conductive mesostructures in the functional device systems would inevitably undergo repetitive out-of-plane compressions during practical operations, and thus, anti-fatigue design strategies are of great significance to improve the reliability of 3D flexible electronics. Previous studies mainly focused on the fatigue failure behavior of planar ribbon-shaped geometries, while anti-fatigue design strategies and predictive failure criteria addressing 3D ribbon-shaped mesostructures are still lacking. This work demonstrates an anti-fatigue strategy to significantly prolong the fatigue life of 3D ribbon-shaped flexible electronics by switching the metal-dominated failure to desired polymer-dominated failure. Combined in situ measurements and computational studies allow the establishment of a failure criterion capable of accurately predicting fatigue lives under out-of-plane compressions, thereby providing useful guidelines for the design of anti-fatigue mesostructures with diverse 3D geometries. Two mechanically reliable 3D devices, including a resistance-type vibration sensor and a janus sensor capable of decoupled temperature measurements, serve as two demonstrative examples to highlight potential applications in long-term health monitoring and human-like robotic perception, respectively.

Palmitoylated GLB1L4 transfers via exosomes to maintain sperm function in rat epididymis.

Epididymal specific proteins play a crucial role in sperm maturation. Some of the post-translational modified proteins are transported from the caput to the cauda of the epididymis through exosomes which regulate the function of sperm in cauda epididymis. Rat beta-galactosidase-1-like protein 4 (GLB1L4) expressed specifically in the caput epididymis, localizes on the sperm; however, the regulatory ways in which GLB1L4 protein interacts with sperm to maintain sperm function are unclear. In this study, knockdown of rat GLB1L4 could inhibit in vitro capacitation of sperm in cauda epididymis and reduce the fertility of the male rats by injection of special lentivirus-shRNA into caput epididymis. Moreover, a considerable proportion of GLB1L4 proteins from rat caput epididymis were loaded on exosomes. The exosomes loaded GLB1L4 from in vitro primary rat caput epididymal epithelial cells could bind with spermatozoa in cauda epididymis. Further, the palmitoylation status of cysteine residues at the 12th and 15th sites of the protein molecule could significantly affect cellular localization of GLB1L4 protein. It was identified that most of GLB1L4 was palmitoylated in the presence of exosomes from primary caput epididymal cells and the level of palmitoylated GLB1L4 in the exosomes could be inhibited by 2-bromopalmitate (2-BP). These results suggested that the palmitoylated GLB1L4 from rat caput epididymis could be transported to the cauda epididymis to regulate the sperm function by exosomes.

Bioinspired design and assembly of a multilayer cage-shaped sensor capable of multistage load bearing and collapse prevention.

Flexible bioinspired mesostructures and electronic devices have recently attracted intense attention because of their widespread application in microelectromechanical systems (MEMS), reconfigurable electronics, health-monitoring systems, etc. Among various geometric constructions, 3D flexible bioinspired architectures are of particular interest, since they can provide new functions and capabilities, compared to their 2D counterparts. However, 3D electronic device systems usually undergo complicated mechanical loading in practical operation, resulting in complex deformation modes and elusive failure mechanisms. The development of mechanically robust flexible 3D electronics that can undergo extreme compression without irreversible collapse or fracture remains a challenge. Here, inspired by the multilayer mesostructure of Enhydra lutris fur, we introduce the design and assembly of multilayer cage architectures capable of multistage load bearing and collapse prevention under large out-of-plane compression. Combined in situ experiments and mechanical modeling show that the multistage mechanical responses of the developed bionic architectures can be fine-tuned by tailoring the microstructural geometries. The integration of functional layers of gold and piezoelectric polymer allows the development of a flexible multifunctional sensor that can simultaneously achieve the dynamic sensing of compressive forces and temperatures. The demonstrated capabilities and performances of fast response speed, tunable measurement range, excellent flexibility, and reliability suggest potential uses in MEMS, robotics and biointegrated electronics.

Single-site binding of pyrene to poly(ester-imide)s incorporating long spacer-units: prediction of NMR resonance-patterns from a fractal model.

Co-polycondensation of the diimide-based diols N,N'-bis(2-hydroxyethyl)hexafluoroisopropylidene-diphthalimide, (HFDI), and N,N'-bis(2-hydroxy-ethyl)naphthalene-1,4,5,8-tetracarboxylic-diimide, (NDI), with aliphatic diacyl chlorides ClOC(CH2) x COCl (x = 5 to 8) affords linear copoly(ester-imide)s. Such copolymers interact with pyrene via supramolecular binding of the polycyclic aromatic at NDI residues. This interaction results in upfield complexation shifts and sequence-related splittings of the NDI 1H NMR resonances, but gives a very different final resonance-pattern from the copolymer where x = 2. Computational modelling of the polymer with x = 5 suggests that each pyrene molecule binds to just a single NDI residue rather than by intercalation between a pair of NDI's at a tight chain-fold, as was found for x = 2. The new single-site binding model enables the pattern of 1H NMR resonances for copolymers with longer spacers (x = 5 to 8) to be reproduced and assigned by simulation from sequence-specific shielding factors based on a type of fractal known as the last-fraction Cantor set. As this type of fractal also enables an understanding of pairwise binding systems, it evidently provides a general numerical framework for supramolecular sequence-analysis in binary copolymers.

Voltammetric immunoassay of human IgG based on the release of cadmium(II) from CdS nanocrystals deposited on mesoporous silica nanospheres.

The authors describe a nanocomposite that was obtained by in-situ deposition of CdS nanocrystals on mesoporous silica nanospheres (MSNs), and its use in an electrochemical immunoassay of human immunoglobulin G (HIgG). The MCN/CdS nanocomposite was covalently modified with the antibodies against HIgG and then employed in a voltammetric immunoassay at antibody-functionalized magnetic beads. Through sandwich immunoreaction, the MCN/CdS nanoprobes are quantitatively captured onto the magnetic beads where numerous Cd(II) ions are released in an acidic solution. The Cd(II) can be detected by anodic stripping voltammetry at a typical working potential of -0.78 V (vs. Ag/AgCl). In combination with the high loading of CdS on MSNs, the use of the stripping voltammetric analysis renders the method high sensitivity. A wide linear range varying from 0.01 to 100 ng mL-1 is obtained for HIgG detection with a lower detection limit at 2.9 pg mL-1. In addition, the preparation of the nanoprobe is inexpensive. The magnetic bead-based assay does not require complex manipulations. Therefore, this method is deemed to possess a wide scope in that it may be applied to other immunoassays. Graphical abstract Graphical Abstract contains poor quality and small text inside the artwork. Please do not re-use the file that we have rejected or attempt to increase its resolution and re-save. It is originally poor, therefore, increasing the resolution will not solve the quality problem. We suggest that you provide us the original format. We prefer replacement figures containing vector/editable objects rather than embedded images. Preferred file formats are eps, ai, tiff and pdf.A TIFF file at 900 dpi resolution of the Graphical Abstract has been attached via this online system. Schematic presentation of the preparation of the mesoporous silica nanosphere (MSN)/CdS nanocomposite for the electrochemical immunoassay of human IgG at magnetic beads. The high decoration of CdS on MSN and the stripping voltammetric analysis of Cd(II) ions render the method high sensitivity.