Application of biosynthesized metal nanoparticles in electrochemical sensors

J. Serb. Chem. Soc. 87 (4) 401–435 (2022) JSCS–5531 Review Published 12 November 2022 REVIEW Application of biosynthesized metal nanoparticles in electrochemical sensors TOTKA DODEVSKA*, DOBRIN HADZHIEV, IVAN SHTEREV and YANNA LAZAROVA Department of Organic Chemistry and Inorganic Chemistry, University of Food Technology, 26 Maritsa Boulevard, Plovdiv 4002, Bulgaria (Received 21 May, revised 17 August, accepted 1 October 2021) Abstract: Recently, the development of eco-friendly, cost-effective and reliable methods for synthesis of metal nanoparticles has drawn a considerable attention. The so-called green synthesis, using mild reaction conditions and natural resources as plant extracts and microorganisms, has established as a convenient, sustainable, cheap and environmentally safe approach for synthesis of a wide range of nanomaterials. Over the past decade, biosynthesis is regarded as an important tool for reducing the harmful effects of traditional nanoparticle synthesis methods commonly used in laboratories and industry. This review emphasizes the significance of biosynthesized metal nanoparticles in the field of electrochemical sensing. There is increasing evidence that green synthesis of nanoparticles provides a new direction in designing of cost-effective, highly sensitive and selective electrode-catalysts applicable in food, clinical and environmental analysis. The article is based on 157 references and provided a detailed overview on the main approaches for green synthesis of metal nanoparticles and their applications in designing of electrochemical sensor devices. Important operational characteristics including sensitivity, dynamic range, limit of detection, as well as data on stability and reproducibility of sensors have also been covered. Keywords: biosynthesis; green synthesis; nanomaterials; nanotechnology; modified electrodes; review. CONTENTS 1. INTRODUCTION 2. GREEN SYNTHESIS OF METAL/METAL OXIDE NANOPARTICLES USING PLANTS 3. GREEN SYNTHESIS OF METAL/METAL OXIDE NANOPARTICLES USING MICROORGANISMS * Corresponding author. E-mail: https://doi.org/10.2298/JSC200521077D 401 Available on line at www.shd.org.rs/JSCS/ ________________________________________________________________________________________________________________________ (CC) 2022 SCS. 402 DODEVSKA et al. 4. ELECTROCHEMICAL SENSORS BASED ON BIOSYNTHESIZED METAL/METAL OXIDE NANOPARTICLES 4.1. Electrochemical sensors based on biosynthesized AgNPs 4.2. Electrochemical sensors based on biosynthesized AuNPs 4.3. Electrochemical sensors based on other biosynthesized metal and metal oxide nanoparticles 5. CONCLUSIONS AND FUTURE PERSPECTIVES 1. INTRODUCTION Nowadays green nanotechnology has remained at the forefront of scientific research due to its outstanding approaches and applications. Green nanotechnology involves the application of green chemistry principles to the design of valuable and sustainable nanosized materials in a more environmentally benign approach.1 The unique properties of nanomaterials such as catalytic potential,2 optoelectrical properties,3 magnetic behavior4 and biological activity5 are the main factors determining their extremely wide applications in various fields of science, technology and industry. Nanosized materials are widely used as catalysts6 and nanoelectronic components,7 in the composition of antibiotics, antiseptics and disinfectants,8 in drug delivery,9 food and material packaging,10 targeted delivery of pharmaceuticals,11 development of biosensors,12 etc. The main challenge in the development of catalyticaly active nano-sized materials is to prepare nanoparticles that are highly active, selective, stable, robust, and inexpensive. Classical synthesis of metal nanoparticles (MNPs) most commonly involves chemical reduction of metal ions from solutions of their salts in the presence of organic or inorganic reducing agent such as ethylene glycol, dimethylformamide and sodium borohydride (NaBH4), followed by addition of a stabilizing agent.13 The reagents used are usually expensive and toxic substances which could generate hazardous by-products harmful to health and environment.14 Therefore, there is a growing concern to develop new, alternative and sustainable methods for MNPs preparation. Research on the possibilities of using biological systems (plants, bacteria, fungi, algae) to obtain stable MNPs and metal oxide NPs has been particularly intense in recent years. The so-called green synthesis has received more attention as a cost effective and valuable alternative for environmentally safe and energy-efficient production of nanoparticles with desired properties.2,15–19 Unlike chemical and physical processes, bioinspired synthetic methods restrict the use of sophisticated instruments, toxic chemicals and energy (high temperature, pressure, irradiation). Green synthesis of MNPs involves the use of plant extracts or microorganisms for the bioreduction of metal ions into their zero-valent elemental form. Biomolecules such as proteins, sugars, flavonoids, alkaloids, polyphenols, etc. (Fig. 1) act as reducing and capping agents. Regarding the process of metal oxide NPs synthesis in a Available on line at www.shd.org.rs/JSCS/ ________________________________________________________________________________________________________________________ (CC) 2022 SCS. ELECTROCHEMICAL SENSORS BASED ON BIOSYNTHESIZED NANOPARTICLES 403 green way, researchers suggest that specific biomolecules react with the metal ions to reduce or to form complexes. The resulting product is subjected to thermal treatment to get final metal oxide NPs. Therefore, different mechanisms of metal oxide NPs formation were proposed considering the ability of the active compounds in reducing and chelating the metal ions. Fig. 1. Schematic illustration of the natural sources used to synthesize NPs in a green way. Biological systems differ in their capabilities to supply MNPs, hence the production process highly varies depending on the choice of green material. The plant extracts are considered to be more suitable compared to microorganisms for green synthesis of MNPs. Plant extract mediated synthesis of MNPs is preferable due to its economic and ecological effectiveness – easily available plant material, aqueous solvents and normal conditions are used for the synthesis of nanoparticles in a simple one-step procedure. Extensive research shows that the plantassisted synthesis is relatively fast and suitable for large-scale production of stable MNPs. At the same time, delicate, complicated and meticulous preparation steps are required for microbial synthesis of MNPs. Organisms such as bacteria and fungi need to be cultured or propagated in order to obtain sufficient starting materials. Thus, synthesis protocols include prior procedures such as microorganism isolation and identification, growth optimization and culture preparation. Other challenges are the slow reduction process (ranging from hour (...truncated)