Yoon, Su-Jin Nam, Yun-Sik Lee, Ji Young Kim, Jin Young Lee, Yeonhee Lee, Kang-Bong 2024-01-19T15:03:59Z 2024-01-19T15:03:59Z 2021-09-05 2021-03-20 0026-3672 https://pubs.kist.re.kr/handle/201004/117252 Concave gold nanocubes are viable optical nanoprobes for the determination of nitrite ions. Herein, a novel approach was developed, based on the measurement of localized surface plasmon resonance absorption. The addition of nitrite ions selectively induced the etching of concave gold nanocubes, abrading the sharp vertices to spherical corners, which resulted in blue-shifted absorption accompanied by a color change from sapphire blue to light violet. The mechanism of selective etching of concave gold nanocube tips was elucidated by using X-ray photoelectron spectroscopy and atom probe tomography. The optimized detection of NO2- via the concave gold nanocube-based probe occurred at pH 3.0 and in 20 mM NaCl concentration at 40 degrees C. The absorption ratios (A(550 nm)/A(640 nm)) were proportional to the NO2- concentrations in the range 0.0-30 mu M, with a detection limit of 38 nM (limit of quantitation of 0.12 mu M and precision of 2.7%) in tap water. The highly selective and sensitive colorimetric assay has been successfully applied to monitor the nitrite ion concentrations in spiked tap water, pond water, commercial ham, and sausage samples. English Springer Verlag Highly sensitive colorimetric determination of nitrite based on the selective etching of concave gold nanocubes Article 10.1007/s00604-021-04772-7 1 Microchimica Acta, v.188, no.4 Microchimica Acta 188 4 scie scopus 000631114100001 2-s2.0-85103229288 Chemistry, Analytical Chemistry Article Nitrite ion sensor Concave gold nanocubes Etching Colorimetric probe Surface plasmon resonance