Biofouling-Resistant Platinum Bimetallic Alloys

Recent Advances in Bimetallic Nanoporous Gold Electrodes for Electrochemical Sensing

Bimetallic nanocomposites and nanoparticles have received tremendous interest recently because they often exhibit better properties than single-component materials. Improved electron transfer rates and the synergistic interactions between individual metals are two of the most beneficial attributes of these materials. In this review, we focus on bimetallic nanoporous gold (NPG) because of its importance in the field of electrochemical sensing coupled with the ease with which it can be made. NPG is a particularly important scaffold because of its unique properties, including biofouling resistance and ease of modification. In this review, several different methods to synthesize NPG, along with varying modification approaches are described. These include the use of ternary alloys, immersion-reduction (chemical, electrochemical, hybrid), co-electrodeposition-annealing, and under-potential deposition coupled with surface-limited redox replacement of NPG with different metal nanoparticles (e.g., Pt, Cu, Pd, Ni, Co, Fe, etc.). The review also describes the importance of fully characterizing these bimetallic nanocomposites and critically analyzing their structure, surface morphology, surface composition, and application in electrochemical sensing of chemical and biochemical species. The authors attempt to highlight the most recent and advanced techniques for designing non-enzymatic bimetallic electrochemical nanosensors. The review opens up a window for readers to obtain detailed knowledge about the formation and structure of bimetallic electrodes and their applications in electrochemical sensing.

Nanotechnology‐based electrochemical biosensors for monitoring breast cancer biomarkers

Breast cancer is categorized as the most widespread cancer type among women globally. On-time diagnosis can decrease the mortality rate by making the right decision in the therapy procedure. These features lead to a reduction in medication time and socioeconomic burden. The current review article provides a comprehensive assessment for breast cancer diagnosis using nanomaterials and related technologies. Growing use of the nano/biotechnology domain in terms of electrochemical nanobiosensor designing was discussed in detail. In this regard, recent advances in nanomaterial applied for amplified biosensing methodologies were assessed for breast cancer diagnosis by focusing on the advantages and disadvantages of these approaches. We also monitored designing methods, advantages, and the necessity of suitable (nano) materials from a statistical standpoint. The main objective of this review is to classify the applicable biosensors based on breast cancer biomarkers. With numerous nano-sized platforms published for breast cancer diagnosis, this review tried to collect the most suitable methodologies for detecting biomarkers and certain breast cancer cell types.

Microelectrode glucose biosensor based on nanoporous platinum/graphene oxide nanostructure for rapid glucose detection of tomato and cucumber fruits

Microelectrode glucose biosensor based on three-dimensional hybrid nanoporous platinum/graphene oxide nanostructure was developed for rapid glucose detection of tomato and cucumber fruits. The nanostructure was fabricated by a two-step modification method on microelectrode for loading a larger amount of glucose oxidase. The nanoporous structure was prepared on the surface of the platinum microelectrode by electrochemical etching, and then graphene oxide was deposited on the prepared nanoporous electrode by electrochemical deposition. The nanoprorous platinum/graphene oxide nanostructure had the advantage of improving the effective surface area of the electrode and the loading quantity of glucose oxidase. As a result, the biosensor achieved a wide range of 0.1-20.0 mM in glucose detection, which had the ability to accurately detect the glucose content. It was found that the three-dimensional hybrid nanostructure on the electrode surface realized the rapid direct electrochemistry of glucose oxidase. Therefore, the biosensor achieved high glucose detection sensitivity (11.64 μA mM -1cm -2), low detection limit (13 μM) and rapid response time (reaching 95% steady-state response within 3 seconds), when calibrating in glucose standard solution. In agricultural application, the as-prepared biosensor was employed to detect the glucose concentration of tomato and cucumber samples. The results showed that the relative deviation of this method was less than 5% when compared with that of HPLC, implying high accuracy of the presented biosensor in glucose detection in plants.

Environmental aspect and applications of nanotechnology to eliminate COVID-19 epidemiology risk

Herein, we discuss fast development of the new coronavirus disease COVID-19, emerged in late 2019 in Wuhan, Hubei Province, China, the ground zero of the coronavirus pandemic, and associated with relatively high mortality rate. COVID-19 risk originates from its ability to transmit easily from person to person through the respiratory droplets released during sneezing, breathing, talking, singing, or coughing within a range of nearly 1.5–2 m. The review begins with an overview of COVID-19 origin and symptoms that range from common cold to severe respiratory illnesses and death. Then, it sheds light on the role of nanotechnology as an effective tool for fighting COVID-19 via contributions in diagnosis, treatment, and manufacture of protective equipment for people and healthcare workers. Emergency-approved therapeutics for clinical trial and prospective vaccines are discussed. Additionally, the present work addresses the risk of severe acute respiratory syndrome coronavirus transmission via wastewater and means of wastewater treatment and disinfection via nanoscale materials. The review concludes with a brief assessment of the government's efforts and contemporary propositions to minimize COVID-19 hazard and spreading.

Nanobiotechnology as a platform for the diagnosis of COVID-19: a review

A sensitive method for diagnosing coronavirus disease 2019 (COVID-19) is highly required to fight the current and future global health threats due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV 2). However, most of the current methods exhibited high false‐negative rates, resulting in patient misdiagnosis and impeding early treatment. Nanoparticles show promising performance and great potential to serve as a platform for diagnosing viral infection in a short time and with high sensitivity. This review highlighted the potential of nanoparticles as platforms for the diagnosis of COVID-19. Nanoparticles such as gold nanoparticles, magnetic nanoparticles, and graphene (G) were applied to detect SARS-CoV 2. They have been used for molecular-based diagnosis methods and serological methods. Nanoparticles improved specificity and shorten the time required for the diagnosis. They may be implemented into small devices that facilitate the self-diagnosis at home or in places such as airports and shops. Nanoparticles-based methods can be used for the analysis of virus-contaminated samples from a patient, surface, and air. The advantages and challenges were discussed to introduce useful information for designing a sensitive, fast, and low-cost diagnostic method. This review aims to present a helpful survey for the lesson learned from handling this outbreak to prepare ourself for future  pandemic.