Three-in-one multifunctional luminescent metal-organic gels/sodium alginate beads for high-performance adsorption and detection of chlortetracycline hydrochloride, and high-security anti-counterfeiting

Abstract

Effective elimination and real-time detection of chlortetracycline hydrochloride (CTC) contamination in aqueous solutions, and the establishment of fluorescent state security labels for deterring counterfeits, remain formidable challenges. Herein, two hierarchically porous luminescent metal-organic gels (denoted as Tb-MOG and Eu-MOG) are fabricated by an ultrafast aqueous-based synthetic strategy at room temperature, exhibiting exceptional adsorption capacities (297.68 mg·g−1 and 258.78 mg·g−1), high sensitivities (1.48*106 M−1 and 1.12*106 M−1), and low detection limits (0.044 μM and 0.057 μM) towards CTC. More importantly, MOGs/SA beads are constructed by immobilizing MOGs into sodium alginate (SA) matrix, which addresses the deficiencies of difficult recyclability and easy agglomeration of powdered MOGs, accompanied by the enhanced adsorption capacities and excellent reusability. By virtue of exceptional adsorption performances, MOGs/SA beads allow for the continuous treatment of 100 bed volumes (BV) CTC in various water samples. Aside from that, MOGs/SA beads inherit the fluorescence properties of MOGs, which are capable of reflecting the CTC concentrations in real-time and visualizing adsorption processes assisted by smartphones, as well as ensuring their authenticity as anti-counterfeiting materials. Overall, this work furnishes a rational design of multifunctional carrier-based MOGs, and provides valuable insights for dealing with CTC wastewater pollution and counterfeits.