An upconverted nanoparticle–porphyrin metal–organic framework platform for near-infrared detection of nitenpyram

A ratiometric nitenpyram (NIT) upconversion luminescence sensor UCNPs–PMOF was fabricated from a metal–porphyrin organic framework (PMOF) and pretreated UCNPs. The reaction between NIT and the PMOF releases the H2TCPP (5,10,15,20-tetracarboxyl phenyl) porphyrin ligand, which enhances the absorption of the system at 650 nm, and reduces the upconversion emission intensity of the sensor at 654 nm through a luminescence resonance energy transfer (LRET) mechanism, thus achieving the quantitative detection of NIT. The detection limit was 0.21 μM. Meanwhile, the emission peak of UCNPs–PMOF at 801 nm does not change with the concentration of NIT, and the emission intensity ratio (I654 nm/I801 nm) is used to achieve the ratiometric luminescence detection of NIT, and the detection limit is 0.22 μM. UCNPs–PMOF has good selectivity and anti-interference to NIT. In addition, it has a good recovery rate in actual sample detection, which indicates that it has high practicability and reliability in NIT detection.