Application of a Novel “Turn-on” Fluorescent Material to the Detection of Aluminum Ion in Blood Serum

• Published in: ACS applied materials & interfaces 2018-07, Vol.10 (28), p.23667-23673
• Main Authors: Liu, Pai, Li, Wangyang, Guo, Shuai, Xu, Dongrui, Wang, Mengni, Shi, Jianbing, Cai, Zhengxu, Tong, Bin, Dong, Yuping
• Format: Article
• Language: English
• Subjects: Aluminum - blood; Animals; Cell Line; Fluorescent Dyes; Humans; Mice; Spectrometry, Fluorescence
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.8b07658

A novel “turn-on” fluorescent bioprobe, 1,2,3,4,5-penta­(4-carboxyphenyl)­pyrrole sodium salt (PPPNa), with aggregation-enhanced emission characteristics was synthesized for the in situ quantitative detection of Al3+ in serum. It exhibited a high selectivity to Al3+ in both simulated serum and fetal calf serum with no interferences from other metal ions or serum components observed and no isolation required. A weak interaction between PPPNa and serum albumin was found, which caused no interference, but enhanced fluorescence response of PPPNa to Al3+ and improved detection sensitivity. The limit of detection was determined to be 1.50 μmol/L Al3+ in phosphate-buffered saline solution containing 33 μg/mL bovine serum albumin (BSA) and decreased to 0.98 μmol/L as BSA concentration increased to 100 μg/mL. The fluorescence “turn-on” mechanism of the PPPNa probe to detect Al3+ was proposed. A bidentate complex is formed between the carboxy group of PPPNa and Al3+, causing the photoluminescence (PL) emission enhancement by aggregation. BSA chains further strengthen the stacking compactness of the aggregates of PPPNa and Al3+ and consequently enhance the PL emission of PPPNa by further promoting the restriction of intramolecular rotation of the phenyl ring. Its application to the in situ Al3+ was successfully demonstrated with HeLa cells and NIH 3T3 cells. The low cytotoxicity and highly selective response of PPPNa to Al3+ endow its great potentials to in vivo detecting and imaging of Al3+ as well as an absorbent of Al3+.