Development and Characterization of Highly Sensitive Nanostructured Electrochemical Sensors

Abstract

The paper explores the dynamic growth of electrochemical sensors, with a specific emphasis on glucose biosensors, propelled by a surge in demand. Notably, a significant portion of the biosensor market caters to glucose biosensors, essential for measuring blood sugar levels in diabetic patients. Recent studies have been instrumental in leveraging nanomaterials to overcome the limitations associated with non-enzymatic glucose biosensors utilizing noble and transition metals. The primary objective of this research is to introduce a novel approach for compensating for the constraints of non-enzymatic glucose biosensors. This involves synthesizing and coating a nano-structured material, utilizing multi-layered or spherical nanomaterials deposited on electrode surfaces. The central purpose is to achieve a highly sensitive biosensor with an expanded linear range, facilitated by enlarging the specific surface area of the active sites involved in glucose reactions. A noteworthy aspect of the research involves the development of an electrochemical coating method. This method proves to be effective in synthesizing and coating commercially available sensor electrodes with nanomaterials. The successful application of this method in pH-neutral physiological solutions, such as human serum, underscores its potential for real-life scenarios. In Chapter 1, the paper delves into the fundamental understanding of electrochemical sensors and their mechanisms. It highlights the historical challenges associated with enzyme-based glucose biosensors dating back to 1962. These challenges, including susceptibility to environmental factors, oxygen dependence, and the high cost of glucose oxidase (GOx), prompt the introduction of 4th generation glucose biosensors. This chapter provides a comprehensive overview, emphasizing technological advancements and proposing solutions to address current material constraints. In Chapter 2, the focus shifts to addressing the low stability of existing glucose sensors using transition metal Cu. This chapter introduces a non-enzymatic glucose biosensor manufactured by coating a NiFe-LDHs nanostructure on thermally oxidized copper nanowire through an electrochemical method. The resulting multilayer structure, enriched with anions and cations, facilitates substance transfer. The flower-like appearance of the coated surface significantly enlarges the specific surface area of the active site for glucose oxidation. This innovative approach proves to be cost-effective and simple compared to existing electrodes using precious metals. Crucially, the biosensor demonstrates high recovery for glucose in physiological solutions such as DMEM, PBS, and human serum, showcasing its robust performance. In Chapter 3, a novel strategy is introduced to enhance biosensor performance further. The paper describes the creation of a nano-thick Au layer on a commercially available alloy electrode material, followed by the deposition of an iridium oxide layer with exceptional electrochemical properties and biocompatibility. The nanospherical structure of iridium oxide significantly increases the specific surface area for glucose active sites, expanding the glucose detection range. This result holds particular significance in the context of diabetic patients, where blood sugar concentrations can vary widely. The approach successfully overcomes the limitations of previously reported biosensors employing transition metal oxides, highlighting its potential as a miniaturized sensor. In summary, the research paper navigates through these chapters, presenting a comprehensive exploration of non-enzymatic glucose biosensors. It introduces innovative solutions to historical challenges, emphasizing advancements in technology and materials. The proposed biosensors exhibit promising performance characteristics, offering potential applications in real-world scenarios, especially in the context of continuous glucose monitoring for diabetic.