Fluorescence/colorimetric dual-signal sensor based on rare-earth nanosheets for quantitative detection of dopamine

Abstract

A novel fluorescence/colorimetric dual-output dopamine (DA) sensor based on rare-earth nanosheets was constructed. Layered europium hydroxide (NO3-LEuH) was as the precursor, and the organic light-emitting molecule 8-naphthylamine-1-naphthalene sulfonic acid (ANS) and the surface-active molecule 1-octane sulfonate sodium (OS) were as the guests to synthesize fluorescent nanocomposite OS0.2ANS0.8-LEuH with novel emission properties. The nanocomposite was dispersed in a mixed solvent of formamide and water to prepare single-layer nanosheets. Based on fluorescence and ultraviolet absorption analysis, it was confirmed that in the range of 0.001–0.2 mM, the DA concentration had a good positive linear relationship with the fluorescence quenching efficiency F0/F and absorbance, and the response detection limits of the fluorescence method and the colorimetric method were 0.29 μM and 0.058 μM, respectively. The sensor has high specificity recognition ability and can be used for the detection of actual samples, and the dual-signal output sensing strategy greatly improves the accuracy and reliability of detection.