Nanoscale Advances最新文献

Composites of carbon dots (CDs) and metal-organic frameworks (CDs@MOFs) have emerged as a novel class of hybrid nanomaterials that integrate the high porosity and structural versatility of MOFs with the outstanding optical properties and biocompatibility of CDs. Although relatively new, these materials have attracted growing interest as multifunctional platforms for applications in biosensing of bioactive molecules, drugs, and biomarkers, as well as in cancer diagnosis and treatment and antibacterial activity, thereby expanding their potential in biomedicine. The promising performance demonstrated in these areas underscores the need to review and analyze recent advances, along with the benefits and challenges associated with this new class of materials. This review aims to provide a summary of the progress made in the synthesis of CDs@MOFs, including the methodologies and precursors employed, and highlights how the synthesis approach directly influences material properties and guides the selection of the appropriate CDs@MOFs hybrid material based on the desired application. Subsequently, the applications of CDs@MOFs in biosensors for the detection of bioactive molecules, drugs, and biomarkers are discussed, emphasizing advances in detection mechanisms, analytical performance, and stability. Their emerging applications in cancer diagnosis and treatment, antibacterial activity, and wound therapy are also reviewed. Finally, current challenges are discussed, including the control of CD distribution within MOF structures, stability in physiological media, and the need for sustainable and cost-effective synthesis methods, along with an overview of future research and development opportunities.

Promoting cell growth is required in life science and medical applications. Thus far, microdevice researchers have been developing microperfusion systems for simulating in vivo conditions that are suited for cell growth. For advancing cell growth technology further, we applied plasma technology. Plasma is the fourth state of matter after solid, liquid, and gas. When plasma is generated under atmospheric conditions, it reacts with ambient air, producing reactive oxygen and nitrogen species (RONS), which affect cells. These RONS can be used as triggers for promoting cell growth. In this study, we achieved the delivery of RONS to the cells in a microperfusion system using simple methods. We evaluated plasma effects on cell growth and analyzed RONS propagation in a liquid medium for cells under microperfusion.

In this project, a novel hybrid nanostructure l-arginine-modified magnetic zeolite-NaY (Arg@zeolite-Y-Fe₃O₄) was successfully designed and synthesized. It was further characterized using standard analytical techniques including FT-IR, FE-SEM, EDX, BET, TEM, XRD, VSM and TGA. The resulting magnetic mesoporous material was employed as a highly active organocatalyst for the synthesis of chromene analogues via a one-pot, three-component reaction between aldehydes, malononitrile and either phenols or active methylene reagents (e.g., dimedone) under aqueous conditions. This nanocatalyst offers several notable advantages: facile and cost-effective synthesis, environmentally friendly reaction conditions, excellent catalytic performance, and easy magnetic separation. Moreover, it demonstrates remarkable recyclability with minimal loss of activity over multiple cycles. The use of water as a green solvent, along with high product yields and benign operational conditions, highlights the sustainable and practical nature of this catalytic system.

A wide range of methods currently exist for testing the presence of malaria, each with its own advantages and disadvantages. New technologies are urgently needed to develop more effective diagnosis tools to fight and eradicate malaria. Optical biosensors that employ surface plasmon resonance (SPR) techniques are a promising category of devices for detecting malaria biomarkers. One such biomarker is plasmodium lactate dehydrogenase (pLDH), a protein produced during the life cycle of the malaria parasite, which is a metabolic enzyme found in all plasmodium species, including the most widespread falciparum. This work reports on the design, probing, and experimental performance of an optical biosensor for detecting pLDH based on SPR and extraordinary optical transmission. The biosensor is composed of an aluminum metasurface made from an array of nanoholes. The sensor operates in the visible spectral region and achieves label-free sensing of plasmodium falciparum LDH (pfLDH) spiked in phosphate-buffered saline. The sensor has a spectral sensitivity of 360 nm per RIU and an LOD of 1.3 nM, equivalent to 45.6 ng mL^-1 of pfLDH. This type of optical biosensor may offer a cost-effective and high sensitivity method for active infection diagnosis.

Over the past decade, substantial research has focused on identifying cancer biomarkers using Raman spectroscopy. However, no commercial Raman-based diagnostic tests are currently available. A major barrier is the need to amplify the inherently weak Raman signal, typically achieved through Surface-Enhanced Raman Spectroscopy (SERS). Because SERS relies on nanostructured substrates, its clinical translation has been hindered primarily by poor reproducibility, which undermines data reliability and prevents regulatory approval. In this pilot study, we evaluate an improved SERS substrate based on Ag/Ni/NiO nanowires, previously reported by our group, which significantly enhances sensitivity, specificity, detection limits, and critically substrate reproducibility. We further strengthen analytical performance by incorporating machine learning methods for spectral interpretation. Using this optimized platform, we analyzed SERS spectra from tissue samples of 31 breast cancer patients and compared them with matched healthy controls. Our results demonstrate a clear spectral distinction between cancerous and non-cancerous tissue. More importantly, we showed that SERS combined with machine learning, can differentiate major breast cancer subtypes, including luminal A (LUMA), luminal B (LUMB), HER2-enriched (HER2), and triple-negative breast cancer (TNBC). PCA-LDA modeling yielded exceptional diagnostic metrics, achieving up to 99% accuracy, sensitivity, and specificity across multiple classification tasks. Although this pilot study includes a limited number of samples, the findings demonstrate that improved SERS substrates paired with machine-learning analysis can generate a unique molecular fingerprint of breast cancer and its subtypes. This work opens a pathway for developing assays, potentially using blood or saliva, to enable early detection and subtype identification based on SERS-derived cancer fingerprints.

Zinc sulfide (ZnS) quantum dots (QDs) were synthesized using a series of substituted thioureas as single-source sulfur precursors in a high-temperature 1-octadecene medium. The hot-injection method offered excellent reproducibility and enabled straightforward scale-up to multigram quantities without compromising particle size or optical characteristics. The as-prepared ZnS QDs exhibited a high organic content (∼46 wt%), originating from in situ-generated surface ligands, which was quantitatively determined through acid digestion. This surface composition provided a versatile platform for subsequent ligand exchange. Functional ligands, including 2-mercaptopropionic acid (2-MPA), bis[2-(methacryloyloxy)ethyl] phosphate (BMEP), and 10-(phosphonooxy)decyl methacrylate (PODM), were successfully introduced, yielding hydrophilic, hydrophobic, and polymer-reactive ZnS QDs. Structural analysis (XRD, STEM, EDS, FTIR, XPS) confirmed the formation of cubic ZnS QDs with uniform particle sizes (6-8 nm) and verified the incorporation of the new ligands without altering the ZnS core. Optical measurements revealed size-dependent absorption and emission properties across the thiourea series, as well as pronounced ligand-dependent modulation of photoluminescence intensity and decay kinetics. Finally, pristine and functionalized QDs were incorporated into PMMA, PVK, PEG, and methacrylate-based copolymers to form uniform emissive thin films, with AFM demonstrating smooth surface morphology for most systems. These results establish substituted thioureas as effective precursors for scalable ZnS QD synthesis and highlight ligand engineering as a powerful tool for tuning surface chemistry and enabling direct polymer integration.

Retraction of ‘Investigating new bilosomes for ex vivo skin deposition, in vitro characterization, and transdermal delivery of nimodipine’ by Ananda Kumar Chettupalli et al., Nanoscale Adv., 2024, Accepted Manuscript, https://doi.org/10.1039/d4na00510d.

Pt-Ru alloys have shown promising catalytic activity toward the hydrogen evolution reaction (HER) in acidic media; however, their stability remains a critical challenge due to the oxidation and dissolution of Ru species in 0.5 M H₂SO₄. Herein, the synthesis and comparative assessment of a series of electrocatalysts based on a carbon xerogel loaded with platinum and ruthenium, Pt-Ru, specifically a pure carbon xerogel (CX), 5 wt% platinum-loaded CX (Pt5/CX), 5 wt% platinum and 2.5 wt% ruthenium co-loaded CX (Pt5:Ru2.5/CX), and 5 wt% platinum and 5 wt% ruthenium co-loaded CX (Pt5:Ru5/CX) were evaluated for the HER. The carbon xerogel served as a high-surface-area, porous, and conductive substrate, promoting uniform distribution of the metallic nanoparticles, mitigating Ru leaching, and improving charge transfer during the HER. The Pt5:Ru2.5/CX composite displayed superior catalytic activity, achieving the lowest overpotential (39 mV, at 10 mA cm^-2), minimal Tafel slope (29 mV dec^-1), and maximal double-layer capacitance (C _dl of 52.68 mF cm^-2) in 0.5 M H₂SO₄. The improved HER activity is ascribed to the synergistic interaction between Pt and Ru, together with reduced charge transfer resistance (R _ct, 0.4 Ω) and active site accessibility afforded by the carbon xerogel matrix.

All-metal halide perovskite quantum dots (QDs), such as CsPbBr₃ (CPB), exhibit outstanding optoelectronic properties, but their poor thermal stability limits practical applications. In this work, CPB QDs were embedded into mesoporous SBA-15 silica matrices functionalized with amino (NH₂) and sulfonic acid (SO₃H) groups to enhance stability. The SBA-15 host, synthesized hydrothermally and post-functionalized, offers high thermal and chemical resilience. CPB QDs prepared via hot-injection retained their optical features upon incorporation, with consistent photoluminescence and absorption spectra. Structural analysis confirmed uniform QD loading (∼17 nm) within the pores. Among all supports, SO₃H-functionalized SBA-15 provided the greatest stability improvement, attributed to strong interactions with surface ligands. This approach presents a viable pathway for stabilizing perovskite QDs in optoelectronic applications.

We present the first demonstration of atomic force microscopy-based photothermal-induced resonance (PTIR) measurements of hydrated polymers under aqueous conditions, utilizing microfluidic cells with a graphene layer as an atomically thin IR-transparent window. Our findings show that polymer swelling can be successfully detected through changes in the PTIR spectrum.