Review of Cobalt-Based Nanomaterials as Sensors for Water Contaminants

Amidst the outbreak of the Coronavirus Disease 2019 (COVID-19), the detection and assessment of metal/nonmetal ions, drugs, pesticides, proteins, nucleic acids, viruses, and other pathogens have become paramount for effective water environmental quality management. Cobalt metal nanomaterials have emerged as promising candidates for diverse applications spanning catalysis, sensing, and environmental sciences. Their unique catalytic ability, as well as their electrochemical redox capabilities and peroxidase-mimicking activity, make them effective substitutes for biological enzymes. Recent research advancements have showcased the potential of cobalt-based nanomaterials, particularly cobalt metal–organic frameworks (Co-MOFs), which have achieved numerous breakthroughs in optical, electrochemical, and photoelectrochemical sensing. However, the limitations of single metal materials in terms of catalytic activity, stability, and electronic properties have prompted the evolution toward binary and ternary cobalt-based nanocomposites. To fully exploit the potential of these promising materials for practical applications, the development of effective strategies for controlling structural defects and engineering the chemical functional groups of cobalt-based nanocomposites is crucial for producing high-quality, cost-effective, and environmentally friendly cobalt-based nanomaterials. Additionally, enhancing the anti-interference capability of cobalt-based nanomaterial sensors and optimizing their applicable conditions are essential next steps. The insights presented in the review will provide valuable support for the further development and wider adoption of cobalt-based nanomaterials in practical applications, contributing to advancements in water environmental quality management and beyond.