- 标题
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- 实验方案
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Dry Magnetic Separation on the Recovery of Metal Fragments from Kerf Slurry Waste Produced during the Manufacture of Photovoltaic Solar Cells
摘要： In the interest of reducing the cost of photovoltaic production while preserving the environment, a sawing rejection treatment was carried out by recovering the metals with an efficiency estimated to be 96%. To achieve this outcome, first, the sawing rejection was washed with acetone to dissolve the polyethylene glycol. It was then dried in an oven at 70 °C to obtain a slurry powder. This later, powder has undergone a dry magnetic separation under different electric current intensity to recover metals. The metal-containing phase has been characterized by the X-ray diffractometer and the scanning electron microscope. Finally, a simulation on the recovery of metal fragments in the slurry generated during the manufacture of photovoltaic briquettes.
关键词： Metals,Slurry,Dry magnetic separation,Photovoltaic cell,Polyethylene glycol (PEG),Scanning electron microscopy (SEM)
更新于2025-09-23 15:19:57
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DNA enzyme mediated ratiometric fluorescence assay for Pb(II) ion using magnetic nanosphere-loaded gold nanoparticles and CdSe/ZnS quantum dots
摘要： Based on the inner filter effect mechanism of quantum dots, a ratiometric fluorescence nanoprobe was constructed for the determination of Pb(II) ion. Green emitting quantum dots conjugated with DNA substrate (DNA2) acted as donors providing green fluorescence, while gold nanoparticles coupled with DNA enzyme (DNA1) as acceptors quench the green fluorescence. Meanwhile, Fe3O4 nanosphere served as magnetic substrates to facilitate separation process and red fluorescence as an “inner rule” to eliminate the background signal. In the presence of Pb(II) ion, the DNA1 specifically recognize and capture Pb(II) ion with enhanced catalytic activity, which can cleave DNA2 and “turn on” the green fluorescence (I540), while the red fluorescence (I630) remained unchanged. In this way, the ratio of I540/I630 reflects the Pb(II) ion in the system, enabling the quantitative and selective determination of Pb(II) ion over nine different metal ions. Under optimal conditions, the ratiometric fluorescence assay showed good linearity (R2 = 0.98) within the range 10 to 100 ng mL?1. The limit of detection (LOD) was calculated to be 1.79 pg mL?1 (S/N = 3, n = 3, ±3.8%). The proposed fluorescence nanoprobe provides better sensitivity and accuracy than non-ratiometric signal evaluation for Pb(II) ion determination.
关键词： Fluorescence nanoprobe,Inner rule,Magnetic separation,Tea sample,Metal ions,Inner filter effect
更新于2025-09-23 15:19:57
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Fe3O4@PDA immune probe-based signal amplification in surface plasmon resonance (SPR) biosensing of human cardiac troponin I
摘要： This work reports immunomagnetic separation technology-assisted surface plasmon resonance (SPR) biosensing for human cardiac troponin-I (cTnI), a well-known diagnostic marker for myocardial damage. Au film modified by Au nanoparticles (AuNPs) and polydopamine (PDA) was employed as the platforms for immobilizing capture antibody (cAb) and SPR sensing. Magnetic immune probe was prepared by attaching detection antibody (dAb) on the surface of Fe3O4 nanoparticles (Fe3O4 NPs) coated by PDA for precise capture, magnetic separation and enrichment of target analyte (cTnI) from samples. This extraction process greatly improves the sensitivity and effectively reduces the nonspecific interference from complex matrixes. The analyte cTnI collected via Fe3O4@PDA-dAb immune probe can be specially recognized by cAb immobilized on the sensing platform. By introducing secondary antibody (Ab2) conjugated with multi-walled carbon nanotube-PDA-AgNPs (MWCNTs-PDA-AgNPs/Ab2) to the sensing system, the residual binding sites of cTnI were occupied, and the SPR response signals were further amplified. The obtained detection limit for cTnI is 3.75 ng mL-1, which is 320-folds lower than that achieved by PDA-based sensing strategy. The present method was applied to the examination of serum samples spiked with cTnI, and the good recoveries demonstrate its future applicability in clinical diagnosis.
关键词： Polydopamine,Human cardiac troponin-I (cTnI),Immune probe,Surface plasmon resonance (SPR),Magnetic separation
更新于2025-09-19 17:15:36
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Calcium ion assisted fluorescence determination of microRNA-167 using carbon dotsa??labeled probe DNA and polydopamine-coated Fe3O4 nanoparticles
摘要： A selective and sensitive fluorescence biosensor is described for determination of microRNA-167 using fluorescent resonant energy transfer (FRET) strategy. The FRET system comprises carbon dots (CDs, donor) labeled with probe DNA (pDNA) and polydopamine (PDA)-coated Fe3O4 nanoparticles (Fe3O4@PDA NPs, acceptor). The CDs-pDNA can be absorbed onto the surface of Fe3O4@PDA NPs because of the strong π interaction between pDNA and PDA. With the enhanced adsorption ability of Fe3O4@PDA NPs by Ca2+, the fluorescence intensity of CDs at 445 nm (excitation at 360 nm) is quenched. In presence of microRNA-167, the hybridized complex of CDs-pDNA-microRNA-167 will be released from the surface of Fe3O4@PDA NPs due to the weak π interaction of the complex and PDA. This results in the fluorescence recovery of CDs. By application of twice-magnetic separation, the biosensor shows a wide linear range of 0.5–100 nM to microRNA-167 with a 76 pM detection limit. The method was applied to the determination of microRNA-167 in samples of total microRNA extractions from A. thaliana seedlings, and the recoveries ranged from 96.4 to 98.3%.
关键词： Fluorescent resonant energy transfer,Twice-magnetic separation,MicroRNA extractions,Hybridized complex,π interaction,Fluorescence biosensor
更新于2025-09-19 17:13:59
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Treatment of Spent LED Light Bulbs for Recycling of Its Components: A Combined Assessment in the Context of LCA and Cost-Benefit Analysis
摘要： Recently, the demand for LED light bulbs is rapidly increasing due to an increasing demand for energy saving lightning options. In this work, the elemental composition of LED light bulbs is first analyzed, and then a flowsheet for recovering LED chips and other valuable metals from spent LED light bulbs is put forward. The suggested flowsheet includes eddy current separation (ECS) and air tabling, in addition to several refining processes. The experimental results indicated that the eddy current separation and the air tabling are useful techniques for sorting components of LED bulbs, enabling the recycling of aluminium, plastics, and precious metals, such as gold and silver. Next, five different scenarios for treatment of spent LED light bulbs were considered and a combined life cycle assessment (LCA) and cost-benefit analysis was carried out to find out the most suitable alternative. The results of the combined assessment suggested that the recycling of mainly Al and plastics from spent LED bulbs is an environmentally friendly and cost-effective alternative.
关键词： Magnetic separation,Density separation,LCA,REE,LED
更新于2025-09-12 10:27:22
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Gold-assembled silica-coated cobalt nanoparticles as efficient magnetic separationunits and surface-enhanced Raman scattering substrate
摘要： Magnetic and optical bifunctional nanoparticles that combine easy separation, preconcentration, and efficient SERS capabilities have been fabricated with high sensitivity and reproducibility through a low-cost method. These gold nanoparticles attached on magnetic silica-coated cobalt nanospheres (Co@SiO 2 /AuNPs) display the advantage of strong resonance absorption due to gaps at nanoscale between neighboring metal nanoparticles bringing large field enhancements, known as “hot spots”. The prepared particles can be controlled by using an external magnetic field, which makes them very promising candidates in biological applications and Raman spectroscopic analysis of dissolved organic species. The magnetic property of the prepared particles lowers the detection limits through preconcentration with solid-phase extraction in SERS analysis. The performance of the prepared nanostructures was evaluated as a SERS substrate using brilliant cresyl blue (BCB) and rhodamine 6G (R6G) as model compounds. The solid-phase affinity extraction of 4-mercapto benzoic acid (4-MBA) using bifunctional Co@SiO 2 /AuNPs nanoparticles followed by magnetic separation and the measurement of the SERS signal on the same magnetic particles without elution were investigated. Approximately 50-fold increase in SERS intensity was achieved through solid-phase extraction of 8.3 × 10 (cid:0)6 M 4-MBA in 10 min.
关键词： surface modification,Bifunctional nanoparticles,preconcentration,surface enhanced Raman scattering,core-shell nanoparticles,magnetic separation
更新于2025-09-11 14:15:04
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Material Identification of Single-Organic Particles Realized by Observing Their Field-Induced Translations
摘要： A method is proposed that can efficiently identify the material of a single-organic particle; the identification is realized by improving an apparatus formerly used to observe the field-induced translations of particles. Using this new setup, the material of an unidenti?ed organic particle can be determined without consuming the sample. Specifically, the diamagnetic susceptibility χDIA of the particle was obtained from its translating velocity induced in a field-gradient produced by an Nd magnetic circuit, and its material was identi?ed by comparing the experimental χDIA value with a list of published values. In principle, the proposed method of identi?cation based on the χDIA value is effective even for micrometersized particles because the mass measurement of the sample is unnecessary. Hence, the method can be used to thoroughly extract and identify a rare material from a mixture of heterogeneous particles without consuming the sample, before performing a re?ned analysis.
关键词： microgravity condition,Nd–Fe–B magnet,magnetic separation,material separation,organic materials
更新于2025-09-10 09:29:36
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Locked Nucleic Acid Nanomicelle with Cell-Penetrating Peptides for Glutathione-Triggered Drug Release and Cell Fluorescence Imaging
摘要： Herein, we constructed a multi-functional spherical nanomicelle drug delivery system to improve the efficiency of cell uptake. The paclitaxel (PTX)-locked nucleic acid (LNA) monomer and the carboxyfluorescein (FAM)-labeled DNA was mixed together to assemble and form a spherical nanomicelle which was functionalized with transactivator of transcription (TAT), a cell-penetrating peptides (CPPs). A bioreductively activated disulfide was used to link the hydrophobic PTX to the LNA, allowing the PTX to be released freely in the presence of glutathione (GSH) upon cell uptake. Based on magnetic separation, synthetic process of PTX-LNA monomers avoid time-consuming and labor-intensive shortcoming. Cellular uptake of PTX-LNA-TAT nanomicelle and the drug release occur rapidly as proved by fluorescence microscopy and flow cytometry. The resulting nanomicelle was greater stability, monodisperse size, and the high therapeutic potential. Furthermore, the system can readily achieve detection of GSH in the cancer cells. The detection limit for commercial GSH determined was 1.0×10-9 M by using PTX/Fluorescein isothiocyanate (FITC)-LNA/ black hole quencher 1 (BHQ-1) as a probe.
关键词： glutathione,delivery system,locked nucleic acid,magnetic separation,transactivator of transcription peptide
更新于2025-09-09 09:28:46