Application of magnetic-nanoparticle functionalized whole-cell biosensor array for bioavailability and ecotoxicity estimation at urban contaminated sites

Intelligent monitoring of the available lead (Pb) and cadmium (Cd) in soil samples based on half adder and half subtractor molecular logic gates

The available heavy metals in soil samples can cause the direct toxicity on ecosystems, plants, and human health. Traditional chemical extraction and recombinant bacterial methods for the available heavy metals assay often suffer from inaccuracy and poor specificity. In this work, we construct half adder and half subtractor molecular logic gates with molecular-level biocomputation capabilities for the intelligent sensing of the available lead (Pb) and cadmium (Cd). The available Pb and Cd can cleave DNAzyme sequences to release the trigger DNA, which can activate the hairpin probe assembly in the logic system. This multifunctional logic system can not only achieve the intelligent recognition of the available Pb and Cd according to the truth tables, but also can realize the simultaneous quantification with high sensitivity, with the detection limits of 2.8 pM and 25.6 pM, respectively. The logic biosensor is robust and has been applied to determination of the available Pb and Cd in soil samples with good accuracy and reliability. The relative error (Re) between the logic biosensor and the DTPA + ICP-MS method was from -8.1 % to 7.9 %. With the advantages of programmability, scalability, and multicomputing capacity, the molecular logic system can provide a simple, rapid, and smart method for intelligent monitoring of the available Pb and Cd in environmental samples.

A comprehensive review on enzyme-based biosensors: Advanced analysis and emerging applications in nanomaterial-enzyme linkage

Biosensors with nanomaterials and enzymes detect and quantify specific targets in samples, converting recognition into measurable signals. The study explores the intrinsic synergy between these elements for detecting and quantifying particular targets in biological and environmental samples, with results demonstrated through bibliometric analysis and a comprehensive review of enzyme-based biosensors. Using WoS, 57,331 articles were analyzed and refined to 880. Key journals, countries, institutions, and relevant authors were identified. The main areas highlighted the multidisciplinary nature of the field, and critical keywords identified five thematic clusters, revealing the primary nanoparticles used (CNTs, graphene, AuNPs), major application fields, basic application themes, and niche topics such as sensitive detection, peroxidase activity, and quantum dot utilization. The biosensor overview covered nanomaterials and their primary applications, addressing recent advances and inherent challenges. Patent analysis emphasized the U.S. leadership in the industrial sector, contrasting with China's academic prominence. Future studies should focus on enhancing biosensor portability and analysis speed, with challenges encompassing efficient integration with recent technologies and improving stability and reproducibility in the nanomaterial-enzyme interaction.