Photoluminescent Detection of Nitrite with Carbon Nanodots Prepared by Microwave-assisted Synthesis

Abstract

A photoluminescent detection method for nitrite with high selectivity and sensitivity using carbon nanodots (CNDs) is demonstrated. The selectivity of nitrite is accomplished by a highly specific diazotization reaction between nitrite and p-phenylenediamine (p-PDA). In the presence of nitrite, p-PDA easily reacts to form the diazonium cation in the acidic aqueous solution. By alkalization of the reaction mixture, diazonium cation of p-PDA was converted to an aryl radical to form aggregated CNDs, which causes the change in the photoluminescent intensity of CNDs. In the present method, nitrite can be selectively detected down to 1 μM over several anions, such as nitrate, perchlorate, sulfate, fluoride, chloride, and bromide at mM levels.

Capillary Electrophoretic Characterization of Water-soluble Carbon Nanodots Formed from Glutamic Acid and Boric Acid under Microwave Irradiation

“…4,5 Concerned with the analytical applications, some of the present authors (Morita, et al) have prepared CNDs from glucose and polyethylene glycol by microwave irradiation, and the CNDs were utilized for the detection of nitrite by quenching of the photoluminescence. 6 Nitrogen-contained and sulfur-contained CNDs were also prepared from amino acids. 7 Doping of N or S to CNDs developed the quantum yield.…”

Microwave-assisted Derivatization of Fatty Acids for Its Measurement in Milk Using High-Performance Liquid Chromatography

“…21 Microwave-assisted heating exhibits the advantages to accelerate the rate of chemical reactions through thermal effect due to microwave absorption by polar substances. [23][24][25][26][27][28] In the past few decades, the use of microwaves in the organic synthesis and derivatization for GC/LC analysis is gradually increasing, replacing the conventional heating techniques. The major advantage of microwave irradiation is that it generates efficient internal heating by the direct coupling of electromagnetic waves with the molecules, particularly dipole or ionic molecules, present in the reaction mixture.…”