Simultaneous and Sensitive Detection of Three Pesticides Using a Functional Poly(Sulfobetaine Methacrylate)-Coated Paper-Based Colorimetric Sensor

Structurally modified carbon nanotubes as twisted fibers towards electrochemical detection of environmentally hazardous cartap

Pesticides such as cartap play a crucial role in agriculture, as they are extensively used in controlling pests in crops like sugarcane, rice and vegetables. However, their excessive usage poses major threats to human health, causing neurotoxicity and respiratory disorders. In addition, they harm aquatic ecosystems by disrupting biodiversity. Consequently, effective detection and remediation are essential to minimize their adverse effects on human health and the ecosystem. For this purpose, an electrochemical method was used for the simultaneous detection and degradation of the under-reported insecticide cartap. In this work, vertically aligned carbon nanotube arrays were grown and converted into fibers via simple mechanical spinning and used as a flexible electrode material for cartap electro-oxidation. The fabricated electrode exhibited excellent performance towards sensing and remediation without any surface modification. The fiber-based electrode showed a wide linear range, a low detection limit (LOD) of 0.575 mM, high sensitivity (7.98 μA cm-2 mM-1), reproducibility, and excellent electrocatalytic activity. The multi-functionality of this electrode was attributed to its unique properties like flexibility, compatibility with various media (aqueous and organic), cost-effectiveness, and seamless integration with membranes, making these fibers promising candidates for on-site facile detection and long-term degradation of cartap.

Advancements in SERS based systematic evolution of ligands by exponential enrichment for detection of pesticide residues in fruits and vegetables

Fruits and vegetables with pesticide residues pose a serious public health risk. Since 2022, 3 million people worldwide have been poisoned by pesticides annually, with a 20 % fatality rate. This review provides an overview of current research on detecting pesticide residues in produce, focusing on the potential of SERS-based aptasensor. These sensors offer improved efficiency and accuracy in pesticide analysis, ensuring the safety of fruits and vegetables. The review also discusses essential techniques for efficient aptamer production, highlighting their advantages and disadvantages. It emphasizes the benefits and challenges of using SERS-based aptasensor, particularly the need for enhanced anti-interference capabilities and the development of intelligent sensors for on-site detection without extensive sample preparation. This comprehensive review is a great resource that can help with future developments in pesticide residue analysis, food safety, and consumer health protection in contemporary agriculture.

Surface Modification of Nanopores in an Anodic Aluminum Oxide Membrane through Dopamine-Assisted Codeposition with a Zwitterionic Polymer

Surface modification through dopamine-assisted codeposition with functional zwitterionic polymers can provide a simple and one-step functionalization under ambient conditions with robust and stable dopamine-surface interactions to improve the hydrophilicity of nanoporous membranes, thereby expanding their applicability to nanofiltration, ion transport, and blood purification. However, a significant knowledge gap remains in our comprehension of the mechanisms underlying the formation and deposition of dopamine/polymer aggregated coatings within nanoscale confinement. This study explores a feasible method for membrane modification through the codeposition of dopamine hydrochloride (DA) and poly(sulfobetaine methacrylate) (PSBMA) on nanopores of anodic aluminum oxide (AAO) membranes. Our findings demonstrate that the aggregated coatings of DA and PSBMA nanocomposites can effectively deposit on the surfaces within cylindrical AAO nanopores, significantly enhancing the hydrophilicity of the nanoporous membranes. The morphology and homogeneity of the nanocomposite coatings within the nanopores are further investigated by varying PSBMA molecular weights and AAO pore sizes, revealing that higher molecular weights result in more uniform deposition. This work sheds light on understanding the codeposition of DA and zwitterionic polymers in nanoscale environments, highlighting a straightforward and stable surface modification process of nanoporous membranes involving functional polymers.

Progress in the design of portable colorimetric chemical sensing devices

The need for precise determination of heavy metals, anions, biomolecules, pesticides, drugs, and other substances is vital across clinical, environmental, and food safety domains. Recent years have seen significant progress in portable colorimetric chemical sensing devices, revolutionizing on-the-spot analysis. This review offers a comprehensive overview of these advancements, covering handheld colorimetry, RGB-based colorimetry, paper-based colorimetry, and wearable colorimetry devices. It explores the underlying principles, functional materials (chromophoric reagents/dyes and nanoparticles), detection mechanisms, and their applications in environmental monitoring, clinical care, and food safety. Noble metal nanoparticles (NPs) have arisen as promising substitutes in the realm of sensing materials. They display notable advantages, including heightened sensitivity, the ability to fine-tune their plasmonic characteristics for improved selectivity, and the capacity to induce visible color changes, and simplifying detection. Integration of NPs fabricated paper device with smartphones and wearables facilitates reagent-free, cost-effective, and portable colorimetric sensing, enabling real-time analysis and remote monitoring.