specic applications. Bioconjugate methods are created with at least one biologi­cally derived molecule in order to provide targeted drug delivery, reduce off-target effects, and improve therapeutic effectiveness [7]. These bioconjugates are cutting­edge treatment modalities with potential synergistic anticancer effects, and they have the strength to outperform the drawbacks of chemotherapeutics. To get around these problems, researchers have combined different molecules, transport mecha­nisms, and imaging modalities with therapeutic agents or medications [8].

Surface functionalization modies the surface characteristics of 2D materials by adding functional groups or molecules to their surface [24]. To do this, a number of chemical processes may be utilized, including silanization, thiolation, and diazo­nium chemistry. In the case of silanization, for instance, a silane compound reacts with the material’s surface to create covalent connections between the molecules of the silane and the atoms on the surface [25]. The addition of biocompatible poly­mers, such as polyethylene glycol (PEG), can create a hydrophilic and stealth-like surface, reducing protein adsorption and immune response. This introduces new functional groups and changes the surface properties of the 2D material. Functional groups like amino (-NH2) or carboxyl (-COOH) can be introduced, which can serve as reactive sites for further bioconjugation or facilitate interactions with biological molecules [26]. These functional groups can also impart hydrophilicity or hydropho­bicity to the surface, depending on the specic modication. By controlling the type

CVD is a widely used method for the synthesis and growth of thin lms and 2D materials. It involves the building up of a thin lm material onto a substrate by intro­ducing reactive gases into a reaction chamber. Within this chamber, the gases undergo reactions, resulting in the deposition of the desired material onto the sub­strate’s surface [33]. In the CVD process, precursor gases containing the targeted elements are introduced into the reaction chamber, typically maintained at elevated temperatures. These precursor gases can be in the form of vapors, liquids, or solids that vaporize during the process. Inside the chamber, the precursor gases undergo chemical reactions, leading to the formation of volatile by-products and the deposi­tion of the desired material onto the substrate [34].

By enhancing the accumulation of therapeutic chemicals in the intended areas, this tailored administration improves treatment effectiveness while reducing adverse effects on healthy tissues [46]. Au NPs also play a crucial role in theranostics by combining therapeutic and diagnostic functions. Their unique plasmonic properties enable enhanced imaging capabilities. In techniques like dark-eld microscopy and photoacoustic imaging, Au NPs act as contrast agents, enhancing contrast and reso­lution for precise imaging. This imaging aspect allows for real-time monitoring of drug delivery, assessment of treatment response, and visualization of therapeutic efcacy. Furthermore, Au NPs can be utilized in hyperthermia-based therapies [47]. By harnessing the plasmonic properties of Au NPs, localized heating can be achieved when exposed to light, such as NIR laser irradiation. This localized hyper­thermia effect selectively damages cancer cells while sparing healthy tissues, offer­ing a promising approach for targeted cancer treatment. The combination of targeted drug delivery and hyperthermia-based therapies using Au NPs holds great potential in improving treatment outcomes and minimizing adverse effects [48]. Moreover, the stability and biocompatibility of Au NPs, along with their tunability through size and surface modications, make them well-suited for biomedical applications. As we delve into their distinctive capabilities, AuNPs unveil a pathway toward pre­cision medicine, presenting a sophisticated framework for rened therapeutic strat­egies and amplied diagnostic methodologies. These NPs can be engineered to have optimal properties for drug delivery, such as controlled release proles and long circulation times in the body [49]. Researchers, such as Choi etal. and Li etal., have explored the synthesis of Au-based nanostructures like Au@PDA nano worms and GNR@PDA.Choi etal. [50] employed dopamine to synthesize gold nano­worms (AuNWs) encapsulated within a polydopamine (PDA) shell. The process involved the rapid assembly of citrate-capped gold NPs into nanoworm structures within a minute. Subsequently, dopamine initiated self-polymerization over 60min, facilitating the growth of a conformal PDA shell on the outer surface of the AuNWs. This PDA shell signicantly enhances the stability of the internal gold nanoworm structure, resulting in core-shell Au@PDA nanoworms, with each worm possessing around 4–5 gold cores. This synthesis approach not only ensured stability but also precise control over the structure of the resulting Au@PDA nanoworms, rendering them amenable to a range of applications. In another study by Li etal. [51], they concentrated on creating GNR@PDA NPs, in which gold nanorods (GNRs) were created via a seed-mediated technique and then covered with a shell made of poly­dopamine. Figure4.1a shows the form and size of as-prepared GNRs as determined by TEM.High-quality GNRs had an aspect ratio of 3.6 (average width: 22nm; average length: 81nm). The procedure for generating PEGylated gold nanorods (GNRs) encompassed mixing GNRs with mPEG−SH followed by their collection through centrifugation. The PEGylated GNRs were subsequently suspended in a Tris buffer and subjected to sonication prior to the addition of dopamine. Dopamineis self- polymerized and coated onto the surface of the PEGylated GNRs. The resulting GNR@PDA NPs were collected through centrifugation. Figure4.1b, c represents the TEM images of GNR@PDA NPs. The polydopamine shell contributed

imaging capabilities, making them indispensable contrast agents for optical imag­ing techniques. Capitalizing on Ag NPs’ scattering and absorption properties bol­sters image resolution, allowing real-time observation of drug delivery and treatment efcacy. To address oxidation concerns, surface functionalization and size, shape, and aggregation control strategies are employed, safeguarding their stability. By coating Ag NPs with biocompatible materials, their circulation longevity is improved, fostering enhanced therapeutic outcomes. Altogether, the remarkable plasmonic features of Ag NPs open new vistas for precise drug delivery and ther­anostic endeavors, holding the potential to transform biomedical applications [55]. Researchers, such as Mondal etal. and Bose etal., have employed various synthesis methods to create tailored Ag NPs for specic applications. These include the cre­ation of plasmonic silver triangular nanoprisms coated with polyvinyl alcohol for enhanced physicochemical qualities and the manufacture of anisotropic silver NPs with surface alterations for targeted drug administration. Mondal et al. [56] employed a synthesis method to create plasmonic anisotropic silver NPs (AgNPs). The process involved mixing AgNO3 and citrate solutions, the addition of hydrazine hydrate immediately after that careful pH control was maintained throughout the synthesis. Subsequently, folic acid was conjugated to the AgNPs, resulting in folate receptor-targeted AgNPs (FA-AgNPs). Further modication involved quenching quercetin (QRC) onto the surface of the FA-AgNPs, leading to the formation of QRC-FA-AgNPs. In a study by Bose etal. [57], dynamic chemical synthesis of polyvinyl alcohol-coated plasmonic silver triangular nanoprisms (PVA-SNT)was accomplished. The synthesis process involved mixing a polyvinyl alcohol aqueous solution with AgNO3 and sodium citrate, followed by the addition of H2O2 and NaBH4. Color changes in the resulting solution indicated the successful formation of PVA-coated silver triangular nanoprisms. A similar synthesis procedure was employed to synthesize silver triangular NPs (SNT), replacing the PVA solution with deionized water. The synthesized PVA-SNT and SNT NPs underwent charac­terization using various techniques.