Probe-impregnated monolithic polymer as a robust solid-state colorimetric chemosensor for selective sensing of Hg2+ in environmental water and cigarette samples

• Published in: Environmental research 2023-03, Vol.220, p.115210-115210, Article 115210
• Main Authors: Gigi, Greeshma, Mohan, Akhila Maheswari
• Format: Article
• Language: English
• Subjects: cigarettes; color; colorimetry; desorption; detection limit; heavy metals; Mercury; Mesoporous; Monolith; Opto-chemosensor; Polymer; polymers; Probe; sorption isotherms; surface area
• ISSN: 0013-9351; 1096-0953
• DOI: 10.1016/j.envres.2023.115210

The current study developed a novel aqua-compatible and naked-eye portable solid-state opto-sensor for selective and sensitive detection of ultra-trace Hg2+ ions. The developed chemosensor was fabricated by the direct impregnation of a chromoionophoric probe composed of 2,3-bis((4-isopropylbenzylidene)amino)maleonitrile (PDPM) onto the surface of structurally tailored porous polymer monolithic framework. The template exhibited a highly porous network with greater surface area, which led to the effective anchoring of probe molecules onto the surface of the polymer template, thus serving as an efficient platform to constitute a regenerative solid-state chemosensor. The sensor rendered a superior color shift from dull white to dijon yellow after complexing with Hg2+. The surface, structural, and morphological aspects of the sensor were evaluated using FE-SEM, HR-TEM, EDAX, SAED, p-XRD, N2 adsorption isotherm, and XPS. Rigorous optimization of the effects of different analytical parameters on the sensing performance of the PDPM sensor material was ensured. The monolithic sensor had an optimum sensing performance at pH 8.0, rapid signal response kinetics of 60s and a broad linear response range of 0.5–150.0 μg/L with a 0.22 μg/L detection limit. Furthermore, the sensor was also tolerant of foreign matrix constituents, thereby enabling it to be highly selective in detecting Hg2+. Sensor recovery was analyzed to be possible via Hg2+ desorption using 0.01 M EDTA without compromising its sensing performance. It had reutilization potential for up to eight regenerative cycles with excellent data reliability (recovery ≥99.4% and RSD ≤1.4%). The practicability of the fabricated sensor was investigated using various water and cigarette samples. Experimental data revealed that the developed chromoionophoric sensor was reusable, eco-friendly, low-cost, and possessed superior sensing capabilities, making it more feasible for on-site analysis of environmental samples. The designed sensor has the potential for further investigations and applications as a sensor kit for facilitating heavy metal detection in remote places. [Display omitted] •Development of a solid-state colorimetric sensor with tunable sensitivity and selectivity for Hg2+.•Highly responsive PDPM probe molecules were anchored in the polymer matrices for sensor fabrication.•The sensor rendered a high recovery rate for Hg2+ and is suited for on-site analysis.•The sensor material was resource-efficient and economi