120th General Meeting of the KCS

Type Oral Presentation
Area Oral Presentation of Young Analytical Chemists I
Room No. Room C311+C312
Time THU 09:20-:
Code ANAL1.O-3
Subject A colorimetric probe to determine NO2- using label free gold nanocrystals
Authors Kyungmin Kim, Yun Sik Nam1, Kang-Bong Lee2,*
Department of Chemistry, Korea University, Korea
1Advanced Analysis Center, Korea Institute of Science and Technology, Korea
2Green City Technology Institute, Korea Institute of Science and Technology, Korea
Abstract A simple and sensitive colorimetric method for the determination of NO2- ions in aqueous samples was developed using gold nanocrystals (AuNCs). The NO2- ion is selectively etched AuNCs and changing the particle shape. This etching resulted in a dramatic color change from vivid blue to light red. Using this methodology, the concentration of NO2- ions in environmental, biological and sitological samples could be quantitatively detected by the naked eye or by using UV-Vis spectrometry. Also, we found that the selectivity and sensitivity of the detection was noticeably improved at the 20mM of NaCl concentration, at which a more obvious color change was observed. The absorption ratios (A550/A650) of the modified AuNCs solution exhibited a linear correlation with NO2- ion concentrations within the linear range of 0.0~10 ppm, and the limits of detection in tap water, pond water and waste water were 38.45 nM and 0.46 μM, respectively. This cost-effective sensing system allows for the rapid and facile determination of NO2- ions in aqueous samples.
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