Probe decorated porous silica and polymer monoliths as solid-state optical sensors and preconcentrators for the selective and fast recognition of ultra-trace arsenic ions

Trapping/Monitoring of Toxic Arsenate in Human Skin Cell Lines: A Route for Preventing Skin Disorders

Prolonged exposure of human cells to toxic arsenate leads to significant skin diseases. To date, continuous and ultrasensitive assessments of toxic arsenate in water and human skin cell lines via simple trapping/monitoring technologies are urgently needed. Herein, nanomonitors based on self-organized multi-geode for trapping/monitoring ultra-trace arsenate concentrations (LOD=0.55ppb) in human skin cell lines were fabricated to prevent skin disorders. For the first time, the structural geode-like hierarchy was constructed via layer-by-layer assembly with nano/microscale features of wide pore openings and mesoporous cavities, enabling suitable diffusion, trapping, and binding of toxic arsenate in human skin cell lines. The biocompatible hierarchal geode with inner and outer receptor-functionalized surfaces revealed a fast in-vitro monitoring/trapping of arsenate in human skin cell lines in order of seconds, with a detection limit below the level affecting skin disorders. The nanomonitor's suitability for extracellular/intracellular tracking/monitoring/trapping toxic arsenate in human skin cell lines has been proven significantly under physiological conditions. Findings confirmed the exceptional characteristics of mesoscale geode-like pores for in-vitro trapping/quantifying toxic arsenate in human skin cell lines from the accumulation of carcinogenic toxicants, thus introducing a route for preventing skin disorders.

Chromophoric Ion Receptor-Decorated Porous Monolithic Polymer for the Solid-State Naked Eye Sensing of Hg(II): An Experimental and Theoretical Approach

The current work presents a perspective to obliterate toxic Hg(II) from an aqueous environment, a strategic environmental remediation and decontamination measure. We report a simple, efficient, and reusable solid-state visual sensing strategy for the selective detection and quantitative recovery of ultratrace Hg(II). The capture of Hg(II) ions was effectuated using a macro-/mesoporous polymer monolith uniformly decorated with an azo-based chromophoric ion receptor, i.e., 7-((1H-benzo[d]imidazol-2-yl)diazenyl)quinolin-8-ol (BIDQ). The porous polymer template was synthesized through free radical polymerization of gylcidylmethacrylate and ethylene glycol dimethacrylate, leading to distinct structural and surface properties that offer exclusive solid-state colorimetric selectivity for Hg(II) upon restricted spatial dispersion of the ion receptor. The sensor provides a broad linear response range of 1-200 μg/L, with an outstanding detection limit of 0.2 μg/L for Hg(II) ions, thus effectuating reliable and reproducible sensing. Optimizing analytical parameters such as solution pH, receptor concentration, sensor quantity, kinetics, temperature, and matrix interference proved to be promising for the real-time monitoring of toxic mercury ions from aqueous/industrial systems, with maximum response in the pH range of 7.5-8.0, with a response time of ≤80 s. Density functional theory (DFT) calculations were employed to study the electronic structure of BIDQ upon chelating with Hg(II) ions, using 6-311G and LAND2Z basis sets.

Fluorescence switchable sensor enabled by a calix[4]arene-Cu(II) complex system for selective determination of itraconazole in human serum and aqueous solution

A switchable fluorescence sensor based on a calix (Monapathi et al., 2021) [4]arene:Cu²⁺ complex (FLCX/Cu) has been developed for the detection of itraconazole (ITZ) with high sensitivity and specificity. For the development of the sensor, the selective complexation of a fluorescent calix (Monapathi et al., 2021) [4]arene derivative (FL-CX) with the Cu²⁺ ion causing fluorescence quenching was utilized. In addition, the sensor properties of the FLCX/Cu prepared were investigated. For this purpose, various substances (selected anions, cations, and drugs) with which ITZ can be found together were studied in an aqueous solution. Limit of detection (LOD) and limit of quantification (LOQ) values were determined in the range of 1.00-60.0 μg/L as 3.34 μg/L and 11.1 μg/L for ITZ, respectively. Moreover, the real sample analyses were performed in human serum and tablet form. Furthermore, the effect of some possible serum contents on sensor performance was also studied. All these studies confirmed the development of a simple, precise, accurate, reproducible, highly sensitive, and very stable fluorescence sensor.