Biodegradable and Flexible Thermoplastic Composite Graphite Electrodes: A Promising Platform for Inexpensive and Sensitive Electrochemical Detection of Creatine Kinase at the Point-of-Care

Paper-based laser-scribed graphene towards wearable plant sensor: A portable electrochemical platform for precision agriculture

A wearable plant sensor, developed on an eco-friendly substrate, is designed for non-destructive, in-situ, and real-time pesticide analysis on plants and fruits. In this study, we introduce a wearable plant sensor fabricated on a paper substrate using the laser-scribed graphene (LSG) technique for the detection of the pesticide paraquat (PQ) in crops. A synergistic effect was observed from the combination of colorless nail polish and the chemically treated paper substrate, leading to the formation of porous, high-performance, conductive graphene-based electrodes via the LSG fabrication process. The device detects PQ by square wave voltammetry (SWV) at concentrations ranging from 0.5 to 100.0 μmol L-1 in a 0.1 mol L-1 Britton-Robinson (BR) buffer (pH 9.0), with a limit of detection (LOD) of 0.082 μmol L-1. The wearable plant sensor demonstrated excellent mechanical durability under repeated bending cycles, simulating real-world conditions on crops. Furthermore, it showed remarkable selectivity in the presence of commonly used pesticides and molecules typically found in natural beverage samples derived from fruits. As proof of applicability, the flexible and sustainable non-enzymatic wearable sensor was applied directly to the surfaces of fruits and leaves to detect PQ using a portable potentiostat and a smartphone. The results confirm its suitability for on-site pesticide detection, making it an effective tool for precision agriculture (PA) applications.

Green Electrochemical Point-of-Care Devices: Transient Materials and Sustainable Fabrication Methods

The spread of point-of-care (PoC) diagnostic tests using electrochemical sensors poses a significant environmental challenge, especially in limited-resource settings due to the lack of waste management infrastructure. This issue is expected to intensify with the emergence of the Internet of Medical Things (IoMT), necessitating eco-friendly solutions for disposable devices. This review discusses efforts to develop green and sustainable PoC diagnostic devices, clarifying terms like biodegradability and transient electronics. It explores potential transient and biodegradable materials and fabrication technologies, emphasizing sustainable electronics with low-energy consumption and low-carbon footprint techniques, particularly favoring printing methods. The review highlights examples of necessary electronic components containing biodegradable materials for electrochemical PoC devices and discusses their role in device sustainability. Finally, it examines the feasibility of integrating these components and technologies into comprehensive biodegradable PoC devices, addressing the imminent need for eco-friendly solutions in diagnostic testing. This comprehensive discussion serves as a guide for researchers and developers striving to mitigate the environmental impact of PoC testing in the era of IoMT and personalized medicine.

Nanoparticle biosensors for cardiovascular disease detection

Early detection and management of cardiovascular diseases (CVDs) are crucial for patient survival and long-term health. CVD biomarkers such as cardiac Troponin-I (cTnI), N-terminal pro-brain natriuretic peptide (NT-proBNP), creatine kinase MB (CK-MB), Galectin-3 (Gal-3), etc are released into the circulation following heart muscle injury, ie, acute myocardial infarction (AMI). Biosensor technology including the use of nanoparticles can be designed to target specific biomarkers associated with CVD, enabling early detection and more rapid intervention to decrease morbidity and mortality. To date, with the combination of developed nanoparticles, several optical and electrochemical-based biosensors have successfully been used detection of CVD biomarkers. Nanomaterials, when introduced as the modifiers of sensor surfaces like electrodes and gold chips, can result in the more comprehensive and more effective immobilization of capture molecules, ie, antibodies, aptamers and other ligands, due to their large surface area. In recent years, inorganic nanoparticles have regularly been used in the production of biosensors mostly due to their excellent response intensification, adaptable functionalization chemistry, shape control, good biocompatibility, and great stability. In this review, we discuss the application of different kinds of nanoparticles for the sensitive and specific detection of CVD biomarkers.

Trends in ready-to-use portable electrochemical sensing devices for healthcare diagnosis

Compared with previous decades, healthcare has emerged as a key global concern in light of the recurrent outbreak of pandemics. The initial stage in the provision of healthcare involves the process of diagnosis. Countries worldwide advocate for healthcare research due to its efficacy and capacity to assist diverse populations. Enhanced levels of healthcare management can be attained by the implementation of rapid diagnostic procedures and cognitive data analysis. Therefore, there is a constant need for smart therapeutics, analytical tools, and diagnostic systems to improve health and well-being. The past decade witnessed enormous growth in the sensing detection systems integrated into smartphones with printed electrodes and wearable patches for the screening of various healthcare diagnostics biomarkers and therapeutic drugs. This review focuses on the expansion of point-of-care technologies and their incorporation into a broader array of portable devices, a critical aspect in the context of decentralized societies and their healthcare systems. Discussions are broadly focused on the different sensing platforms such as solid electrodes, screen-printed electrodes, and paper-based sensing strategies for the detection of various biomarkers and therapeutic drugs. We also discuss the next-generation healthcare wearable sensing device importance and future research possibilities. Finally, the portable electrochemical sensing devices and their future perspective developments towards healthcare diagnosis are critically summarized.

Electroactive Nanomaterials for the Prevention and Treatment of Heart Failure: From Materials and Mechanisms to Applications

Heart failure (HF) represents a cardiovascular disease that significantly threatens global well-being and quality of life. Electroactive nanomaterials, characterized by their distinctive physical and chemical properties, emerge as promising candidates for HF prevention and management. This review comprehensively examines electroactive nanomaterials and their applications in HF intervention. It presents the definition, classification, and intrinsic characteristics of conductive, piezoelectric, and triboelectric nanomaterials, emphasizing their mechanical robustness, electrical conductivity, and piezoelectric coefficients. The review elucidates their applications and mechanisms: 1) early detection and diagnosis, employing nanomaterial-based sensors for real-time cardiac health monitoring; 2) cardiac tissue repair and regeneration, providing mechanical, chemical, and electrical stimuli for tissue restoration; 3) localized administration of bioactive biomolecules, genes, or pharmacotherapeutic agents, using nanomaterials as advanced drug delivery systems; and 4) electrical stimulation therapies, leveraging their properties for innovative pacemaker and neurostimulation technologies. Challenges in clinical translation, such as biocompatibility, stability, and scalability, are discussed, along with future prospects and potential innovations, including multifunctional and stimuli-responsive nanomaterials for precise HF therapies. This review encapsulates current research and future directions concerning the use of electroactive nanomaterials in HF prevention and management, highlighting their potential to innovating in cardiovascular medicine.

Enhancing Kinase Activity Detection with a Programmable Lanthanide Metal-Organic Framework via ATP-to-ADP Conversion

Precise modulation of host-guest interactions between programmable Ln-MOFs (lanthanide metal-organic frameworks) and phosphate analytes holds immense promise for enabling novel functionalities in biosensing. However, the intricate relationship between these functionalities and structures remains largely elusive. Understanding this correlation is crucial for advancing the rational design of fluorescent biosensor technology. Presently, there exists a large research gap concerning the utilization of Ln-MOFsto monitor the conversion of ATP to ADP, which poses a limitation for kinase detection. In this work, we delve into the potential of Ln-MOFs to amplify the fluorescence response during the kinase-mediated ATP-to-ADP conversion. Six Eu-MOFs were synthesized and Eu-TPTC ([1,1':4',1″]-terphenyl-3,3'',5,5''-tetracarboxylic acid) was selected as a ratiometric fluorescent probe, which is most suitable for high-precision detection of creatine kinase activity through the differential response from ATP to ADP. The molecular -level mechanism was confirmed by density functional theory. Furthermore, a simple paper chip-based platform was constructed to realize the fast (20 min) and sensitive (limit of detection is 0.34 U/L) creatine kinase activity detection in biological samples. Ln-MOF-phosphate interactions offer promising avenues for kinase activity assays and hold the potential for precise customization of analytical chemistry.

Electrochemical Paper-Based Nanobiosensor for Rapid and Sensitive Detection of Monkeypox Virus

Monkeypox virus (MPXV) infection was classified as a public health emergency of international concern by the World Health Organization (WHO) in 2022, being transmitted between humans by large respiratory droplets, in contact with skin lesions, fomites, and sexually. Currently, there are no available accessible and simple-to-use diagnostic tests that accurately detect MPXV antigens for decentralized and frequent testing. Here, we report an electrochemical biosensor to detect MPXV antigens in saliva and plasma samples within 15 min using accessible materials. The electrochemical system was manufactured onto a paper substrate engraved by a CO2 laser machine, modified with gold nanostructures (AuNS) and a monoclonal antibody, enabling sensitive detection of A29 viral protein. The diagnostic test is based on the use of electrochemical impedance spectroscopy (EIS) and can be run by a miniaturized potentiostat connected to a smartphone. The impedimetric biosensing method presented excellent analytical parameters, enabling the detection of A29 glycoprotein in the concentration ranging from 1 × 10-14 to 1 × 10-7 g mL-1, with a limit of detection (LOD) of 3.0 × 10-16 g mL-1. Furthermore, it enabled the detection of MPXV antigens in the concentration ranging from 1 × 10-1 to 1 × 104 PFU mL-1, with an LOD of 7.8 × 10-3 PFU mL-1. Importantly, no cross-reactivity was observed when our device was tested in the presence of other poxvirus and nonpoxvirus strains, indicating the adequate selectivity of our nanobiosensor for MPXV detection. Collectively, the nanobiosensor presents high greenness metrics associated with the use of a reproducible and large-scale fabrication method, an accessible and sustainable paper substrate, and a low volume of sample (2.5 μL), which could facilitate frequent testing of MPXV at point-of-care (POC).