Quantitative image analysis method for detection of nitrite with cyanine dye-NaYF:Yb,Tm@NaYF upconversion nanoparticles composite luminescent probe.

In this work, a quantitative image analysis method based on cyanine dye-upconversion nanoparticles composite luminescent nanoprobe for the detection of nitrite was developed. The nanoprobe was constructed by combining the NaYF:Yb,Tm@NaYF upconversion nanoparticles (UCNPs) and the new cyanine dye IR-790. The upconversion nanoparticles transferred energy to IR-790, resulting in the luminescence quenching, while the luminescence of UCNPs was recovered after adding NO. The increase in photons was related to the concentration of NO. Under the optimal experimental conditions, the detection range was 0.20-140 μM and the limit of detection was 0.030 μM. The measurement for NO can be completed in 29 min. The method has the characteristics of fast response (~0.1 s), low sample consumption (10 μL) and powerful data support (550 frame time series images). Furthermore, the quantitative image analysis method was successfully applied for the analysis of nitrite in environmental water and food samples.