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The heavy metal lead (Pb) holds significant importance in the manufacturing industry due to its extensive range of applications. However, its high toxicity poses a serious risk to both environment and human health. Consequently, on-site portable analysis methods have been developed to detect Pb2+, which is advantageous for obtaining timely information regarding environmental pollution. In this study, a fungal-like porous CoS (FP CoS) was discovered to selectively recognize, adsorb, and detect Pb2+. FP CoS exhibited rapid kinetics (reducing from 8.56 mg∙L–1 to 69 µg∙L–1 within 30 min) as well as exceptional adsorption capacity of 88.14 mg∙g−1 for Pb2+. Benefiting from the selective enrichment of Pb2+, the peroxidase-like activity of FP CoS nanoenzyme was further enhanced, enabling colorimetric detection of Pb2+ with a detection limit of 14 ng∙L–1, surpassing numerous reported materials. When applied to environmental samples spiked with 0–100 μg∙L–1 Pb2+, the combination of FP CoS nanosensor and a portable RGB color sensor yielded an impressive recovery percentage of 112 %. Based on these results, the FP CoS nanosensor not only provides a rapid and visually discernible colorimetric approach for trace and ultra-trace Pb2+ but also serves as a sensitive sensor for detecting Pb2+ in various scenarios. [Display omitted] • A fungal-like porous CoS (FP CoS) for the adsorption, removal and monitoring of Pb2+ was generated. • After selective enrichment of Pb2+, the peroxidase-like activity of FP CoS nanoenzyme was further enhanced. • When coupling to an integrated enrichment-detection strategy utilizing the RGB sensor, a detection limit as low as 0.014 μg L−1. • FP CoS nanosensor detect Pb2+ in river water with impressive recoveries of 112–117 %. • The current results provide a new avenue to the on-site detection of Pb2+ ions. [ABSTRACT FROM AUTHOR]

Overcoming the instability and poor recyclability during the practical applications of contaminant scavengers is a challenging topic. Herein, a three-dimensional (3D) interconnected carbon aerogel (nZVI@Fe 2 O 3 /PC) embedding a core-shell nanostructure of nZVI@Fe 2 O 3 was elaborately designed and fabricated via an in-situ self-assembly process. The porous carbon with 3D network architecture exhibits strong adsorption towards various antibiotic contaminants in water, where the stably embedded nZVI@Fe 2 O 3 nanoparticles not only serve as magnetic seeds for recycling, but also avoid the shedding and oxidation of nZVI in the adsorption process. As a result, nZVI@Fe 2 O 3 /PC efficiently captures sulfamethoxazole (SMX), sulfamethazine (SMZ), ciprofloxacin (CIP), tetracycline (TC) and other antibiotics in water. In particular, an excellent adsorptive removal capacity of 329 mg g−1 and a rapid capture kinetics (99% of removal efficiency in 10 min) under a wide pH adaptability (2–8) are achieved using nZVI@Fe 2 O 3 /PC as an SMX scavenger. nZVI@Fe 2 O 3 /PC displays exceptional long-term stability given that it shows excellent magnetic property after it is stored in water solution for 60 d, making it an ideal stable scavenger for contaminants in an etching-resistant and efficient manner. This work would also provide a general strategy to develop other stable iron-based functional architectures for efficient catalytic degradation, energy conversion and biomedicine. [Display omitted] • A 3D interconnected carbon aerogel (nZVI@Fe 2 O 3 /PC) embedding a core-shell nanostructure of nZVI@Fe 2 O 3 was fabricated by an in-situ self-assembly strategy. • The porous carbon with 3D network architecture shows strong adsorption towards various antibiotic contaminants. • An excellent removal capacity of 329 mg g−1 and a rapid capture kinetics (99% of removal efficiency in 10 min) under a wide pH adaptability (2–8) are achieved. • NZVI@Fe 2 O 3 /PC displays exceptional long-term stability given that it shows good adsorption ability after six cyclic tests and excellent magnetism after soaking in water for 60 days. [ABSTRACT FROM AUTHOR]

We for the first time proposed a sandwich mode recognition approach for heavy metal ions based on the solubility product principle, i.e., a metal sulfide with a high solubility product is paired with a metal sulfide with a low solubility product to selectively identify a target heavy metal ion with an intermediate solubility product. In this work, a pair of α-NiS and β-NiS nanostructures with the same composition but different solubility product constants were synthesized, and the relationship of solubility product constants among α-NiS, β-NiS and ZnS is α-NiS < ZnS < β-NiS, conferring very different adsorption properties of α-NiS and β-NiS for Zn(II). The Zn(II) adsorption percentage of α-NiS hollow sphere is 99.5%, while that of β-NiS hollow sphere is only 14.5%. Using this finely designed pair of α-NiS and β-NiS, precise recognition of Zn(II) in mixed ions was realized, perfectly verifying the feasibility of the novel recognition protocol. This recognition method is simple and designable, and may be used for precise identification and rapid enrichment of targeted single or multiple heavy metal ions. [Display omitted] • A sandwich mode recognition approach for Zn(II) was proposed. • The precise identification of Zn(II) is achieved by combining α-NiS and β-NiS. • The mechanism of this recognition method was discussed. • A general protocol that can be used to identify other metal ions was developed. [ABSTRACT FROM AUTHOR]