Fluorescent Sensor for Sequentially Monitoring Zinc(II) and Cyanide Anion in Near-Perfect Aqueous Media

Abstract

We report a new sensor, 1, for sequentially detecting Zn 2+ and CN − based on fluorescence. Sensor 1 was prepared through the reaction of 3-aminobenzofuran-2-carboxamide with 4diethylaminosalicylaldehyde. Sensor 1 showed a selective "off−on" fluorescent response toward Zn 2+ , distinguishing Zn 2+ from Cd 2+ . The limit of 1 (0.35 μM) for monitoring Zn 2+ is lower than the World Health Organization (WHO) guideline (76 μM) for water available for drinking. Importantly, sensor 1 could sense Zn 2+ in living cells and aqueous media. In addition, the resulting 1−Zn 2+ complex functioned as an efficient "on−off" sensor for CN − . The mechanisms of 1 for detecting Zn 2+ and CN − were explained by spectroscopic, spectrometric, and theoretical studies.

Dyes based on the 2(1H)‐quinolone skeleton as potential colorimetric and fluorescent sensors for cyanide anions

“…Currently, fluorescent probes for the detection of cyanide anions take advantage of their characteristic properties such as strong nucleophilicity and high affinity towards copper ions. Cyanide sensors are based on hydrogen bonding, nucleophilic addition to the carbonyl moiety, and formation of cyanide anion complexes . Among these reactions, the nucleophilic addition was found to have a high selectivity and sensitivity for the recognition of cyanide anions.…”

“…Cyanide sensors are based on hydrogen bonding, 13,14 nucleophilic addition to the carbonyl moiety, [15][16][17] and formation of cyanide anion complexes. [18][19][20] Among these reactions, the nucleophilic addition was found to have a high selectivity and sensitivity for the recognition of cyanide anions. Most fluorescent probes are designed to exhibit fluorescence quenching (on-off) and fluorescence enhancement (off-on) as the detection signal.…”

Acridino-Diaza-20-Crown-6 Ethers: New Macrocyclic Hosts for Optochemical Metal Ion Sensing

“…However, its excessive intake is connected to serious disorders [ 19 ]. The detection limit (LOD) of all the recently published sensors [ 20 , 21 , 22 , 23 , 24 , 25 , 26 ] is satisfactory for the maximum permitted level of Zn 2+ in drinking water (5 mg/L ~7.6 × 10 −5 M [ 27 ]). The greatest challenge is to discriminate Zn 2+ from Cd 2+ due to their very similar chemical properties.…”

Keteniminium Salts as Key Intermediates for the Efficient Synthesis of 3‐Amino‐Indoles and ‐Benzofurans

“…For example, 3‐aminoindole is the core of antiviral compounds against hepatitis B virus and of anti‐proliferative agents and such anti‐mitotic properties were also observed with 3‐aminobenzofuran‐based molecules . Those benzofurans are reported to be involved in potent ischemic cell death inhibitors and anti‐microbiotics as well as in selective fluorescent chemosensors of Zn 2+ and CN − ions …”