Wei Zhang

Per- and polyfluoroalkyl substances (PFAS) are now regulated at ultra-trace levels in drinking water, with guideline values in the low ng L ⁻¹ (ppt) range in many jurisdictions, demanding highly sensitive, robust, and cost-effective monitoring tools.

Screening the amount of DNA closely related to early diagnosis of diseases or decoding information in target DNA sequences for biological medicine, infectious identification, or forensic analysis are highly essential in our daily life. This review provides clear understanding of nanostructured sensors (i.e., functionalized electrode-based sensors and nanopores) working for electrochemical assessment of DNA, along with their recent advances and unaddressed issues. Crucial constituents for sensor functionalization, electrochemical techniques, and electrodes, used in functionalized electrode-based sensors are briefly introduced, followed by analysis of using this type of sensors for DNA determination and the comparison of performances such as dynamic ranges and detection limits with other similar works. Subsequently, nanopore sensors including porin-based and solid-state nanopores applied for DNA sequencing are the other interests of discussion in the review. Beyond the achievement of high-resolution DNA sequencing based on porins coupled with enzymatic components, commonly used methods to solid-state nanopore creation, practical use of solid-state nanopores in DNA analysis, and computational modeling for nucleobase pore-threading simulation are depicted in more detail. Finally, conclusions in relation to recent advances and future developments are described. This work offers a powerful guideline for electrochemical assessment of DNA using either functionalized electrode-based sensors or nanopores, enabling scientific groups to have an entire picture upon electrochemical nanodevices used for DNA characterization.

Four indispensable constituents of electrochemical biosensors for EDCs detection in water: effective signal transduction pathways, highly conductive electrodes, various functional additives for surface modification, and biorecognition elements.

Coffee industry produces more than eight million tons of waste coffee grounds (WCG) annually. These WCG contain caffeine, tannins, and polyphenols and can be of great environmental concern if not properly disposed of. On the other hand, components of WCG are mainly macromolecular cellulose and lignocellulose, which can be utilized as cheap carbon precursors. Accordingly, various forms of carbon materials have been reportedly synthesized from WCG, including activated carbon, mesoporous carbon, carbon nanosheets, carbon nanotubes, graphene sheet fibers (i.e., graphenated carbon nanotubes), and particle‐like graphene. Upcycling of various biomass and/or waste into value‐added functional materials is of growing significance to offer more sustainable solutions and enable circular economy. In this context, this review offers timely insight on the recent advances of WCG derived carbon as value‐added electrode materials. As electrodes, they have shown to possess excellent electrochemical properties and found applications in capacitor/supercapacitor, batteries, electrochemical sensors, owing to their low cost, high electrical conductivity, polarization, and chemical stability. Collectively, these efforts could represent an environmentally friendly and circular economy approach, which could not only help solve the food waste issue, but also generate high performance carbon‐based materials for many electrochemical applications.