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Abstract: Bacterial infections represent one of the leading causes of mortality worldwide, nevertheless the design and development of rapid, cost‐efficient and reliable detection methods for pathogens remains challenging. In recent years, electrochemical sensing methods have gained increasing attention for the detection of pathogenic bacteria, due to their increasingly competitive sensitivity. However, combining sensitivity with cost efficiency, high selectivity and a facile working procedure in a portable device is difficult. The presented review provides a summary of biosensing strategies for bacteria, published since 2015, by covering significant achievements towards custom‐designed portable point‐of‐care devices. Herein, the direct chemical recognition of bacteria via enzyme activity or secretion products, as well as their detection at various electrode surfaces and materials, such as nanomaterials, indium tin oxide or paper‐based immunosensors, is discussed. Furthermore, newly established hyphenated sensing principles, incorporated into lab‐on‐a‐chip and microfluidic devices, are presented and remaining technical challenges and limitations are considered. [ABSTRACT FROM AUTHOR]

The article reports on the use of scanning electrochemical microscopy (SECM) as an analytical technique to monitor electrochemical activity of a surface. The fundamental element of SECM is a small-scale electrode that serves as high spatial resolution, recording alterations in electrochemical potential having remarkable sensitivity and mobile probe. SECM measurements fuse with other biosensing techniques can conduct multiple experiments on a living project.

[Display omitted] • Plant extracts have been successfully used for the green synthesis of nanomaterials. • Vegetal extracts offer a cost-effective route to synthesize nanomaterials. • Biosynthesized nanomaterials can be employed as electrode modifiers. • The analytical features of electrochemical sensors can be greatly enhanced. Green synthesis of nanomaterials, with its application in electrochemical (bio)sensing, is a blooming field of research as it enables the development of sensitive electroanalytical detection devices with a minimized impact on the environment. Combining the outstanding physicochemical properties of nanomaterials with the eco-friendly and cost-effective features of green synthetic routes has proven to be greatly beneficial to the field of Electroanalytical Chemistry. Studies demonstrate the successful use of natural extracts obtained from plant tissues, such as leaves, seeds, roots, barks and fruits, to obtain nanomaterials. Bioactive compounds in plant tissues simultaneously act as reducing, capping and functionalizing agents, enabling nanoparticle synthesis procedures to be completed in a single step. The modification of electrochemical sensing platforms with biosynthesized nanostructures can considerably enhance their detection properties toward several relevant analytes, such as drugs, vitamins, metal ions and emerging pollutants. This review highlights the most recent achievements in terms of green synthesis of nanomaterials for the fabrication of eco-friendly electrochemical sensors and biosensors, with a special focus on zero-valent noble metal nanoparticles (MNPs), metal oxide nanoparticles (MONPs) and carbon-based nanomaterials. [ABSTRACT FROM AUTHOR]

• The most recent achievements in electrochemical biosensing of COVID-19 are reviewed. • Special focus is placed on biosensing strategies and surface chemistry. • Bioelectrochemistry enables the effective detection of diverse COVID-19 biomarkers. • Prospects on the commercialization of electrochemical biosensors are discussed. Electrochemical biosensors are known for their high sensitivity, selectivity, and low cost. Recently, they have gained significant attention and became particularly important as promising tools for the detection of COVID-19 biomarkers, since they offer a rapid and accurate means of diagnosis. Biorecognition strategies are a crucial component of electrochemical biosensors and determine their specificity and sensitivity based on the interaction of biological molecules, such as antibodies, enzymes, and DNA, with target analytes (e.g., viral particles, proteins and genetic material) to create a measurable signal. Different biorecognition strategies have been developed to enhance the performance of electrochemical biosensors, including direct, competitive, and sandwich binding, alongside nucleic acid hybridization mechanisms and gene editing systems. In this review article, we present the different strategies used in electrochemical biosensors to target SARS-CoV-2 and other COVID-19 biomarkers, as well as explore the advantages and disadvantages of each strategy and highlight recent progress in this field. Additionally, we discuss the challenges associated with developing electrochemical biosensors for clinical COVID-19 diagnosis and their widespread commercialization. [ABSTRACT FROM AUTHOR]