## 1 Introduction  
Cancer is the second leading cause of death worldwide, and was associated with nearly 10 million deaths globally in 2020 [1, 2]. Specifically, ovarian and breast cancer caused 207,252 and 684,996 global deaths, respectively, in 2020 [2]. The complexity of cancer, however, has meant that despite extensive research efforts, the treatments and therapies available are focused on extending survival; the only curative treatment is to surgically remove tumours in early-stage cancers [3]. Current available therapies and treatments that patients can receive include chemotherapy, surgery, radiotherapy, immunotherapy,photodynamic therapy (PDT), and photothermal therapy (PTT). Treatment is highly dependent on the type of cancer and the progression of the disease. One of the most common treatments is chemotherapy, which utilises toxic agents to kill cancerous cells but often consequently induces collateral damages to healthy tissues due to the off-target toxic side effects that are associated with chemotherapy [4]. To eliminate the off-target toxic side effects of chemotherapeutic agents, cancer therapy requires the use of targeted drug delivery platforms. Nanomaterials offer the opportunity to accurately target the site of interest while reducing the dosage required to elicit an effect. Nanoscience is the study and manipulation of materials on a scale of 1-100 nm, which brings together multiple disciplines, including physics, engineering, materials science, biology, and medicine [5]. In the last century nanotechnology has been implemented into a range of different fields, such as food and agriculture, electronics, energy, and cosmetics. The most significant advances, however, have been in biomedicine and healthcare [5; 6]. Nanomedicine is the application of nanotechnology in medicine, with the goal of improving healthcare and current treatments and controlling and preventing diseases through diagnostics, imaging, and therapeutics [7; 8]. Nanomaterials themselves can be defined as manufactured materials with one or more external dimensions in the nanoscale range of 1-100 nm [9; 10]. Nanomaterials offer unique physical characteristics that are often very different from their larger counterparts due to their small size and large surface area to volume ratio. Furthermore, nanomaterials can be engineered to alter their optical, electrical, mechanical, and magnetic properties, as well as their size, shape, and chemical composite to make them most suited for their intended application [10; 11]. These properties offer unique advantages and have been utilised for therapeutics, diagnostics, and imaging within the healthcare field. In addition, many biological mechanisms within the body take place on a nanoscale, meaning that nanomaterials can move freely and have a great opportunity to cross natural barriers, be taken up by cells, interact with biomolecules, and bind receptors [7]. The favourable characteristics of nanoparticles (NPs) have seen the rapid development of nanoparticle-mediated drug delivery systems for use in neurodegenerative, infectious, and autoimmune diseases, as well as in cancer applications; there are currently a host of NPs that have been approved for clinical use by the Food and Drug Administration (FDA). A more detailed account of the FDA-approved therapeutic NPs and those currently in clinical and pre-clinical trials is beyond the scope of this research paper. Readers can be directed to the following papers for more information [12; 13; 14; 15]. Principally, targeted nano-delivery systems are being extensively developed for use in cancer treatments; more than 20% of the therapeutic NPs approved and in pre-clinical or clinical trials have been developed for anti-cancer applications [12]. Among nanomaterials, graphene has recently emerged as a promising agent for use in diagnostic and therapeutic applications. Graphene is a 2D planar carbon structure composed of a one atom-thick sheet of sp\({}^{2}\) hybridised carbon atoms arranged in a hexagonal crystal lattice.