A Highly Selective Sensor for Cyanide in Organic Media and on Solid Surfaces

Abstract

The application of IR 786 perchlorate (IR-786) as a selective optical sensor for cyanide anion in both organic solution (acetonitrile (MeCN), 100%) and solvent-free solid surfaces was demonstrated. In MeCN, IR-786 was selective to two anions in the following order: CN− > OH−. A significant change in the characteristic dark green color of IR-786 in MeCN to yellow was observed as a result of nucleophilic addition of CN− to the fluorophore, i.e., formation of IR 786-(CN), which was also verified by a blue shift in the 775 nm absorbance peak to 430 nm. A distinct green fluorescence emission from the IR-786-(CN) in MeCN was also observed, which demonstrated the selectivity of IR-786 towards CN− in MeCN. Fluorescence emission studies of IR-786 showed that the lower detection limit and the sensitivity of IR-786 for CN− in MeCN was 0.5 μM and 0.5 to 8 μM, respectively. The potential use of IR-786 as a solvent-free solid state sensor for the selective sensing and monitoring of CN− in the environment was also demonstrated. On solvent-free solid state surfaces, the sensitivity of the IR-786 to CN− in water samples was in the range of 50–300 μM with minimal interference by OH−.

Switchable Optical Probes for Simultaneous Targeting of Multiple Anions

“…Some of the recent examples (53)(54)(55)(56)(57)(58)(59)(60)(61)(62)(63)(64) based on this strategy have been shown in Table 1. [135][136][137][138][139][140][141][142][143][144][145][146]…”

“…Considering this fundamental difference, several groups had achieved simultaneous detection of multiple anions merely varying the polarity of the host medium. Some of the recent examples ( 53‐64 ) based on this strategy have been shown in Table …”

On KCN treatment effects on optical properties of Si-based bilayers

“…It is known that substances containing cyanide are extremely toxic for physiological systems and therefore methods for cyanide ions detection have been under considerable research [10,11]. Optical sensing is mainly based on detecting binding sites of C-C, C-N etc.…”

Substituted 2-Aminobenzothiazoles Salicylidenes Synthesis and Characterization as Cyanide Sensors in Aqueous Medium

“…Recently, many molecular probes have been developed as cyanide sensors with various functionalities such as acyltriazene [ 6 ], carboxamide [ 7 ], squarane [ 8 ], trifluoroacetophenone [ 9 ], acridinium [ 10 ], oxazine [ 11 ], cyanine dyes and related inodoliminium NIR dyes [ 12 ], and Schiff bases. Schiff bases are widely used as sensors for anions [ 13 , 14 , 15 , 16 , 17 , 18 ] and cations [ 19 , 20 , 21 ].…”

“…Different techniques were used to detect cyanide such as voltammetry [ 22 , 23 ], ion chromatography [ 24 ], colorimetric [ 25 , 26 , 27 , 28 ], and UV-vis and fluorescence [ 12 , 17 , 29 , 30 , 31 , 32 , 33 , 34 ]. UV-vis and fluorescence techniques present many advantages such as immediate easy detection, low cost, high sensitivity and quantification of the anions in different solvent systems including biological systems [ 35 ].…”