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Abstract In fighting against infectious diseases such as COVID‐19, simple‐to‐use, sensitive, scalable, and rapid diagnostics are crucial for early disease diagnosis. In this regard, electrochemical biosensors are particularly attractive in developing point‐of‐need diagnostics. Importantly, by being compatible with nano‐ and microfabrication methods, they are amenable to miniaturization, which reduces background noise and the required sample volume. However, miniaturization also reduces the signal level, making it challenging to detect low virus counts. In this work, microfabricated electrochemical sensors with a dual signal amplification scheme based on evaporation‐enhanced redox cycling (E2RC) in a generator–collector configuration are developed. A scalable, nanolithography‐free fabrication method is proposed to achieve a controllable sub‐micrometer gap between three dimensional (3D) interdigitated microelectrodes by combining photolithography with template‐driven electrodeposition. Using the optimized electrodes, the sensors achieve rapid detection with a limit of quantification of ≈1.2 × 10³particles mL⁻¹through continuous measurement in evaporating droplets containing SARS‐CoV‐2 virion mimics. Investigating particle charge and size reveals the role of electrophoretic enrichment in the overall response. The sensor performance is also validated using heat‐inactivated SARS‐CoV‐2 virions, with selective response to SARS‐CoV‐2 against HCoV‐299E, SARS‐CoV S1, and MERS‐CoV S1 (captured using antibody‐functionalized magnetic nanoparticles). The proposed sensing method is sensitive, rapid, scalable, and can be extended to broader applications, including detection of bacteria, extracellular vesicles, and other viruses. 

Recent advances in graphene-based electroanalytical biodevices: different methods for graphene synthesis, functionalization, device fabrication, and transduction mechanisms are discussed for various healthcare applications. 

Abstract Pseudomonas aeruginosa(P. aeruginosa) is an opportunistic pathogen causing infections in blood and implanted devices. Traditional identification methods take more than 24 h to produce results. Molecular biology methods expedite detection, but require an advanced skill set. To address these challenges, this work demonstrates functionalization of laser‐induced graphene (LIG) for developing flexible electrochemical sensors forP. aeruginosabased on phenazines. Electrodeposition as a facile approach is used to functionalize LIG with molybdenum polysulfide (MoS_x). The sensor's limit of detection (LOD), sensitivity, and specificity are determined in broth, agar, and wound simulating medium (WSM). Control experiments withEscherichia coli, which does not produce phenazines, demonstrate specificity of sensors forP. aeruginosa. The LOD for pyocyanin (PYO) and phenazine‐1‐carboxylic acid (PCA) is 0.19 × 10⁻⁶ and 1.2 × 10⁻⁶ m, respectively. Furthermore, the highly stable sensors enable real‐time monitoring ofP. aeruginosabiofilms over several days. Comparing square wave voltammetry data over time shows time‐dependent generation of phenazines. In particular, two configurations—“Normal” and “Flipped”—are studied, showing that the phenazines time dynamics vary depending on how cells interact with sensors. The reported results demonstrate the potential of the developed sensors for integration with wound dressings for early diagnosis ofP. aeruginosainfection.