Selective Colorimetric Sensing of Geometrical Isomers of Dicarboxylates in Water by Using Functionalized Gold Nanoparticles

Abstract

A colorimetric sensing system based on gold nanoparticles functionalized with a water-soluble anion-recognition motif, an o-(carboxamido)trifluoroacetophenone analogue, has been developed. The nanoparticle system selectively senses specific isomers of dicarboxylates that are geometrically favorable for the binding-induced aggregation process; thus, it discriminates a trans-dicarboxylate fumarate from its cis-isomer maleate, and benzene-1,4-dicarboxylate from its isomeric benzene-1,2-and benzene-1,3-dicarboxylates in water, exhibiting a color change from red to blue.

Gold Nanoparticles in Chemical and Biological Sensing

“…275,276 Utilizing this system, discrimination of benzene-1,4-dicarboxylate from its isomers benzene-1,2- and benzene-1,3-dicarboxylate in water was also possible. 276 …”

Efficient Synthesis of Photoreactive 2-Propoxyaniline Derivatives as Artificial Sweeteners

“…Therefore, we selected alternative starting material (11), and it was subjected to demethylation by lithium chloride under a reflux condition 16 to give (12), and this was followed by Williamson ether synthesis 17 to produce (15). Compound (15) was able to be prepared in another way; commercially available 4-propoxybenzaldehyde (13) was treated with CF3-TMS 18 and worked up with 1 M HCl to obtain (14) in good yield. Compound (14) was oxidized with Dess-Martin periodinane under an acidic condition 19 Scheme 3 Synthesis of 2,2,2-trifluoro-1-(4-propoxyphenyl)ethan-1-one Nitration of compound (15) with fuming HNO3 in acetic anhydride at 0 °C proceeded selectively (16).…”

Red or Blue? Gold Nanoparticles in Colorimetric Sensing

“…Following a similar approach, maleate and fumarate were distinguished [26,27]. Compound 3 was used to cap gold nanoparticles (Figure 13).…”