Sensitive quantitative image analysis of bisulfite based on near-infrared upconversion luminescence total internal reflection platform

Cyanine dye-assembled composite upconversion nanoparticles for the sensing and cell imaging of nitrite based on a single particle imaging method

“…1E clearly shows that the characteristic peaks of OA-UCNPs at about 2927 cm −1 and 2855 cm −1 are mainly due to the stretching vibration of the oleic acid ligand, 33 while the absorption peak near 1560 cm −1 comes from the stretching vibration of the carboxyl group (–COOH). Compared with OA-UCNPs, the characteristic absorption peak intensity of NOBF 4 -UCNPs obtained by ligand exchange decreases at 3000–2800 cm −1 , and a new characteristic absorption peak appears near 1100 cm −1 , 34,35 mainly because of the existence of the BF 4 − bond. Then, the infrared spectrum of NOBF 4 -UCNPs-IR-798 found that there is a characteristic peak of carbon–carbon double bonds (CC) at 1695–1630 cm −1 , and a carboxyl group (–COOH) vibration absorption peak at 1200–1500 cm −1 .…”

Upconversion Fluorescence Nanoprobe-Based FRET for the Sensitive Determination of Shigella

“…Recently, the fluorescent probes constructed from a series of functionalized upconversion fluorescent nanoparticles were reported to determine a variety of harmful substances (pesticide mimic diethyl chlorophosphite [ 22 ], heavy metal ions [ 23 , 24 ], bisulfite [ 25 ], Sudan I–IV [ 26 ], and ampicillin [ 27 ]) with high sensitivity and high selectivity. In addition, some novel upconversion fluorescent probes have been developed for the detection of foodborne pathogens in food.…”