# Expanding Horizons: Taking Advantage of Graphene's Surface Area for Advanced Applications
## 2 Increasing the Surface Area of Graphene
### Functionalization  
A significant increase in the effective surface area of graphene is achieved through the process of functionalization, which involves the covalent or non-covalent bonding of different chemical moieties, molecules, or nanoparticles to its surface [29]. This augmentation of the surface area is of paramount significance in diverse applications for several fundamental reasons. The introduction of these functional entities results in a higher degree of surface coverage, manifesting as an expanded lattice structure replete with additional binding sites. These augmentations of its surface possess the potential to facilitate a plethora of interactions and reactions, consequently amplifying the available surface area. The functional groups or molecules grafted onto its surface invariably exhibit unique chemical reactivity or binding affinities. These entities serve as loci for subsequent chemical reactions, molecular adsorption, or targeted molecule binding. This enhanced chemical reactivity imparts a significant increase in the effective surface area with specific propensities for particular interactions. The chemical diversity brought about by functionalization endows graphene with custom-tailored surface properties. Such tailoring enables the modulation of wettability, hydrophilicity, hydrophobicity, or selective reactivity toward distinct molecular species. Thus, the diversity in surface chemistry extends the range of applications and renders it an adaptable platform for multifarious requirements [30]. Its functionalization can bestow it with multifaceted functionalities, including catalysis, sensing, and controlled drug delivery. This further augments the realm of applications and broadens the potential utility of functionalized graphene. In addition to these benefits, functionalization also affords improvements in dispersion and its stability within solvents or matrices. Such enhancements are crucial for incorporation into composite materials and coatings, thereby ensuring an extended effective surface area for interactions with other materials. The realm of biological and biomedical applications exploits the functionalized ability to interface with biomolecules. This leads to the augmentation of the effective surface area for biological interactions and is instrumental in applications such as biosensors, targeted drug delivery, and tissue engineering. Functionalized graphene finds application in chemical and gas sensing due to the selectively reactive nature of the introduced chemical functional groups. These functional groups instigate chemical interactions with target analytes, thus affording heightened sensitivity and specificity of the sensor, correspondingly expanding the effective surface area dedicated to molecular recognition events. Its functionalization, by covalent or non-covalent means, results in a profound increase in the effective surface area, concomitant with diverse surface properties and functionalities [31; 32]. This augmented surface area is important in rendering it as a versatile and indispensable material in a wide array of scientific, industrial, and technological domains.