Appl. Nano, Volume 3, Issue 2 (June 2022) – 3 articles

Glioblastoma multiforme is an aggressive, invasive, fatal primary heterogenic brain tumor. New treatments have not significantly improved the dismal survival rate. Low-level laser therapy reports indicate different tumor cells respond distinctly to low-level laser therapy based on laser dose (J/cm²) or with nanotherapeutics. We investigated the effects of pairing two optical property-driven treatment agents—a low-level laser on glioblastoma multiforme (U251) using an He-Ne laser (632.8 nm) with 18.8 nm spherical Ag-PMMA-PAA nanoparticles, with an absorbance peak at 400 nm with a broad shoulder to 700 nm. The He-Ne treatment parameters were power (14.87 ± 0.3 mW), beam diameter (0.68 cm), and exposure time 5 min leading to a 12.28 J/cm² dose. A dose of 12.28 J/cm² was applied to Ag-PMMA-PAA nanoparticle concentrations (110–225 μM). An amount of 110 μM Ag-PMMA-PAA nanoparticles combined with an He-Ne dose at 18 h yielded 23% U251 death compared to He-Ne alone which yielded 8% U251 death. A 225 μM Ag-PMMA-PAA nanoparticle He-Ne combination resulted in an earlier, more significant, U251 death of 38% at 6 h compared to 30% with 225 μM alone at 18 h. Both treatment agents possess inherent physical and functional properties capable of redesign to enhance the observed cell death effects. Our results provide evidence supporting next-step studies to test “the redesign hypothesis” that these paired optical-driven agents provide a tunable platform that can generate significant U251 cell death increase. Full article

Coinage metal nanoparticles (NPs) are well-known for the phenomenon of localized surface plasmon resonance (LSPR), which is widely utilized for enhanced sensing and detection. LSPR stability over time is an important issue for the practical application of nanoparticle matrices. Some metals, and copper among those, are chemically reactive in ambient atmospheric conditions that leads to degradation of plasmonic functionality. This work reports on the formation of Cu NP matrices utilizing magnetron-sputtering gas-phase aggregation, size-selection and soft-landing on a substrate. This method provides monocrystalline NPs with high purity, thus, improving chemical inertness towards ambient gases, for example, oxygen. Additionally, a simple approach of UV-ozone treatment is shown to form an oxide shell protecting the metallic core against reactions with environmental species and stabilizing the plasmonic properties for a period of over 150 days. The suggested methodology is promising to improve the competitiveness of Cu nano-matrices with those of Au and Ag in plasmonic sensing and detection. Full article

Mycotoxins are secondary metabolic products of fungi. They are poisonous, carcinogenic, and mutagenic in nature and pose a serious health threat to both humans and animals, causing severe illnesses and even death. Rapid, simple and low-cost methods of detection of mycotoxins are of immense importance and in great demand in the food and beverage industry, as well as in agriculture and environmental monitoring, and, for this purpose, lateral flow immunochromatographic strips (ICSTs) have been widely used in food safety and environmental monitoring. The literature to date describing the development of ICSTs for the detection of different types of mycotoxins using different nanomaterials, nanoparticle size, and replicates was reviewed in an attempt to identify the most important determinants of the limit of detection (LOD). It is found that the particle size and type of materials contribute significantly to determining the LOD. The nanoparticle sizes used in most studies have been in the range 15–45 nm and gold nanoparticle-based ICSTs have been shown to exhibit the lowest LOD. Perspectives for potential future development to reduce the LODs of ICSTs are also discussed. Full article