A multifunctional upconversion nanoparticles probe for Cu2+ sensing and pattern recognition of biothiols

作者：Wang, Qian-Qian; Hu, Rong; Fang, Zheng-Qi; Shi, Guoyue; Zhang, Shengqiang^*; Zhang, Min^*

来源：CHINESE CHEMICAL LETTERS, 2022, 33(8): 3782-3786.

DOI：10.1016/j.cclet.2021.11.012

• Upconversion nanomaterials
• Polyacrylic acid
• Copper ion
• Pattern recognition sensor array
• Biothiols

Lanthanide-doped upconversion nanoparticles (Ln-UCNPs) are a new type of nanomaterials with excellent fluorescence properties, which are well applied in fluorescent biosensing. Herein we developed a multi-functional probe based on the surface engineering of core-shell structure UCNPs with polyacrylic acid (PAA). The developed PAA/UCNPs probe could be highly selective to detect and respond to Cu2+ at different pH. Cu2+ could easily combine with the carboxylate anion of PAA to quench the fluorescence of UC-NPs. Therefore, we creatively proposed a fluorescent array sensor (PAA/UCNPs-Cu2+), in which the same material acted as the sensing element by coupled with pH regulation for pattern recognition of 5 thiols. It could also easily identify the chiral enantiomer of cystine (L-Cys-and D-Cys), and distinguish their mixed samples with different concentrations, and more importantly, it could be combined with urine samples to detect actual level of homocysteine (Hcys) to provide a new solution for judging whether the human body suffers from homocystinuria.