Tailoring nanocellulose: A comprehensive exploration of functionalisation with small, macro, and inorganic molecules for enhanced sensing and dual-mode biosensing

Abstract

Nanocellulose materials have gained growing interest in the fields of nanotechnology and materials science due to their outstanding qualities, such as tunable surface chemistry, high specific surface area, low toxicity, and ease of availability from various plant sources, animals and bacteria. These versatile materials are used in a variety of applications, e.g., drug delivery, tissue engineering, sensing and biosensing, fire retardation, catalysis, food packaging, and wastewater treatment because they are renewable, durable, biodegradable, and have unique morphological characteristics and chemical capabilities. The properties of nanocellulose are impacted by how it is extracted and functionalised. This entails the modification of cellulosic nanomaterials through the use of small molecules to induce ionic charges and create hydrophobic surfaces. Additionally, macromolecules, such as polymer grafts on the nanocellulose backbone, are employed to expand its potential applications in diverse dimensions. Moreover, the incorporation of inorganic nanoparticles is pivotal in enhancing various characteristics of nanocellulose, including thermal, mechanical, electrical, optical, and catalytic properties. These modifications collectively enhance the properties of cellulosic nanomaterials, making them valuable in sensing and biosensing applications, as well as reinforcing agents in nanocomposites. The main theme of this review is to offer comprehensive guidance for the preparation of functionalized nanocellulose materials using a diverse array of small molecules, macromolecules, and inorganic nanoparticles. Additionally, the review endeavors to evaluate the potential applications of these materials in the realms of sensing and biosensing. Furthermore, the review aims to provide a detailed overview of dual-mode biosensing platforms, highlighting the unique advantages afforded by cellulosic nanomaterials as dual-functional nanohybrids.