The optical properties and electric field enhancement of gold nanorods for different cases were investigated in this study. The numerical analysis was carried out to understand the functionality and working of gold nanorods, while the experimental portion of the work was focused on the efficiency of gold nanorods for targeted drug delivery. COMSOL Multiphysics was used for numerical analysis. The theoretical results suggest the use of gold nanorods (AuNRs) for anticancer applications. The resonance peaks for gold nanorods of 10 nm diameter were observed at 560 nm. The resonance peaks shifted towards longer wavelengths with an increase in nanorod size. The resonance peaks showed a shift of 140 nm with a change in nanorod length from 25 to 45 nm. On the experimental side, 22 nm, 35 nm and 47 nm long gold nanorods were produced using the seed-mediated growth method. The surface morphology of the nanorods, as well as their optical characteristics, were characterized. Later, gold nanorods were applied to the targeted delivery of the doxorubicin drug. Gold nanorods showed better efficiency for doxorubicin drug loading time, release time, loading temperature, and release temperature. These results reveal that AuNRs@DA possess good ability to load and deliver the drug directly to the tumorous cells since these cells show high temperature and acidity.

The finite element analysis technique was used to investigate the suitability of silver nanorods, spheres, ellipsoids and core–shell structures for the hyperthermia treatment of cancer. The temperature of the silver nanostructures was raised from 42 to 46 °C, in order to kill the cancerous cells. The time taken by the nanostructures to attain this temperature, with external source heating, was also estimated. The heat transfer module in COMSOL Multiphysics was used for the finite element analysis of hyperthermia, based on silver nanostructures. The thermal response of different shapes of silver nanostructures was evaluated by placing them inside the spherical domain of the tumor tissue. The proposed geometries were heated at different time intervals. Optimization of the geometries was performed to achieve the best treatment temperature. It was observed that silver nanorods quickly attain the desired temperature, as compared to other shapes. The silver nanorods achieved the highest temperature of 44.3 °C among all the analyzed geometries. Moreover, the central volume, used to identify the thermal response, was the maximum for the silver nano-ellipsoids. Thermal equilibrium in the treatment region was attained after $0.5 \mathsf{\mu }\mathrm{s}$ of heating, which made these structures suitable for hyperthermia treatment.

Understanding the atomic structure of a material provides the foundation for explaining its macroscopic behavior and predicting its properties. This chapter describes copper’s atomic structure as the basis for its individual characteristics that have made it essential throughout human history. Copper’s electronic configuration (3d¹⁰4s¹) is also explored, highlighting how its single valence electron in the 4 s orbital enables exceptional electron mobility within its face-centered cubic (FCC) crystal structure. The chapter describes copper’s metallic bonding, characterized by delocalized electrons forming a “sea” around positively charged ions, and demonstrates how this arrangement directly enables its outstanding electrical and thermal conductivity. Various structural defects, including vacancies, dislocations, and grain boundaries, are analyzed for their influence on mechanical properties, particularly copper’s remarkable ductility and malleability. Advanced computational models simulating electron movement and atomic interactions at different temperatures provide further insights into structure-property relationships. Through a comprehensive examination of these structural features, the chapter establishes clear connections between atomic-level phenomena and macroscopic properties, offering a theoretical framework essential for understanding copper’s technological applications and developing novel copper-based materials with improved performance characteristics.

The development of efficient and chemically stable photocatalysts with improved charge separation is critical for the remediation of dye-contaminated wastewater. In this study, graphene oxide–magnesium oxide (GO/MgO) nanocomposites with ultralow GO loadings (0–0.05 wt.%) were synthesized through a co-precipitation route and evaluated for ultraviolet (UV)-driven methylene blue (MB) degradation. X-ray diffraction (XRD) results were consistent with the retention of the cubic MgO phase (JCPDS 45-0946) with crystallite refinement from 20.26 to 13.26 nm, while the slight peak-position variations were more consistent with interfacial strain than definitive lattice substitution. UV–visible diffuse reflectance spectra revealed a red shift and bandgap reduction from 5.11 to 4.71 eV. Fourier transform infrared (FTIR) and Raman spectra showed GO-related functional signatures and a decrease in the ID/IG ratio (0.886 → 0.830), suggesting strengthened interfacial interactions with increasing GO loading. The optimized 0.05 wt.% GO/MgO sample achieved 91.6% MB degradation within 180 min and exhibited a 5.24-fold enhancement in the apparent pseudo-first-order rate constant (k = 0.00290 min−1) relative to pristine MgO (0.01518 min−1). Photocatalytic efficiency was maximized at pH 7–9 with a catalyst dosage of 0.75 g L−1, and post-reaction XRD/FTIR analysis indicated good structural stability. The enhancement is attributed to crystallite refinement and GO–MgO interfacial charge-transfer pathways inferred from consistent structural/optical–kinetic correlations.

This study theoretically analyzed the optical properties and electric field enhancement of gold nanospheres. Based on numerical analysis, the gold nanospheres were coated experimentally with diallyldimethylammonium chloride (C₈H₁₆ClN) for targeted drug delivery. Numerically, a resonance peak for 10 nm nanospheres was observed at 510 nm. As the radius increased from 10 nm to 100 nm, the resonance peak shifted from 510 nm to 605 nm. The nanosphere radius also affected the extinction cross-section. The resonance peaks showed a red shift as the radius of the nanosphere increased. For experiment analysis, gold nanospheres were synthesized using a seed-mediated technique and then coated with different concentrations of C₈H₁₆ClN. The UV absorbance by the nanospheres increased with an increase in the concentration of C₈H₁₆ClN from 10 mg ml⁻¹ to 20 mg ml^–1. UV–vis spectrum confirmed a rise in resonance peaks with increasing coating concentration. The coated gold nanospheres were used to deliver the doxorubicin-HCl (DOX-HCl) drug. Maximum drug release was observed when the temperature was set at 50 °C. It was concluded that the nanospheres, coated with 20 mg ml^–1 of C₈H₁₆ClN, are excellent candidates for drug delivery applications. The gold nanospheres with a radius of 50 nm were best for target drug delivery, and the particles above 50 nm were best for thermal therapies for cancer treatment.