A colorimetric squaraine-based probe and test paper for rapid naked eyes detection of copper ion (II)

Tetrasubstituted cyclopentenone‐based fluorescent chemosensors for the selective detection of Fe3+ and Cu2+ ions

“…To explore the practical application of the chemosensors, real sample analysis was performed. Water samples from three sources (tap water and drinking water from the University of Kerala, and lake water from the Karamana river, Thiruvananthapuram) were collected and Fe 3+ and Cu 2+ content were quantitatively detected by the standard addition method 3d. To the three water samples, 3 μM and 6 μM Fe 3+ and Cu 2+ were added separately and were titrated against sensors 3 and 5 .…”

“…Selective and sensitive detection of transition metal ions have gained immense importance over recent years due to the significance of balancing their content both in living systems and the environment . Among the transition metals, iron and copper play key roles in controlling many life processes and for maintaining environmental sustainability . Iron is the second most abundant trace metal, is essential for almost all living organisms and participates in various metabolic processes that includes oxygen transport, DNA synthesis, and electron transfer .…”

“…Fluorescent chemosensors based on quinoline, coumarin, squaraine,3a,13 and rhodamines have been reported recently for the selective detection of iron and copper ions. In the present study we synthesized 4‐hydroxy cyclopentenone‐based chemosensors 3 and 5 by base catalyzed condensation of 1,5‐diphenyl‐pentane‐1,3,5‐trione 1 with 1,2‐diphenylethane‐1,2‐dione and 2,2′‐thenil .…”

Simple, Rapid, and Highly Sensitive Colorimetric Sensor Strips from a Porous Cellulose Membrane Stained with Victoria Blue B for Efficient Detection of Trace Cd(II) in Water

“…4 Because of the hydrogen bonding and van der Waals forces between the hydroxyl groups on the cellulose molecule chains, cellulose can be processed into a stable threedimensional fibrous membrane, which makes it feasible for an ideal carrier to fabricate a cellulose-based colorimetric sensor. 5,6 Besides, cellulose belongs to polysaccharide which is formed by connecting glucose units to one another in a very rigid structure. There are three polar hydroxyl (−OH) groups in each glucose repeating unit, which provide multiple hydrogen bond sites for ions and polar groups in dye molecules to bind with.…”

“…Nowadays, the high-purity cellulose membrane has received increasing attention due to its porosity, renewability, nontoxicity, biodegradability, biocompatibility, and large specific surface area. − Especially, it is prepared by a tape casting method after dissolving cellulose in sodium hydroxide/urea aqueous solution . Because of the hydrogen bonding and van der Waals forces between the hydroxyl groups on the cellulose molecule chains, cellulose can be processed into a stable three-dimensional fibrous membrane, which makes it feasible for an ideal carrier to fabricate a cellulose-based colorimetric sensor. , Besides, cellulose belongs to polysaccharide which is formed by connecting glucose units to one another in a very rigid structure. There are three polar hydroxyl (−OH) groups in each glucose repeating unit, which provide multiple hydrogen bond sites for ions and polar groups in dye molecules to bind with.…”