Portal de Periódicos da CAPES

Colorimetric detection of microcystin-LR based on disassembly of orient-aggregated gold nanoparticle dimers

2015; Elsevier BV; Volume: 68; Linguagem: Inglês

10.1016/j.bios.2015.01.037

1873-4235

Fangfang Wang, Shuzhen Liu, Mingxia Lin, Xing Chen, Shiru Lin, Xiazhen Du, He Li, Hongbin Ye, Bin Qiu, Zhenyu Lin, Longhua Guo, Guonan Chen,

Gold and Silver Nanoparticles Synthesis and Applications

Recently we demonstrated oriented formation of gold nanoparticle (AuNP) dimers for ultrasensitive sensing oligonucleotides (J. Am. Chem. Soc. 2013, 135, 12338). Herein, we investigate the reverse process of this sensing mechanism using target analytes to disassemble the orient-aggregated AuNP dimers. This enables us to expand the analytes from oligonucleotides to other molecules, e.g. highly sensitive and selective determination of microcystin-LR (MC-LR) is selected for a demonstration in this work. Aptamers specific to the target molecules are used as linkers to prepare the AuNP dimers. In the presence of the target molecule, the aptamer changes its structure to bind the target molecule. Thus the pre-formed AuNP dimers are disassembled. As a result, the solution color is changed from blue to red. This sensing design retains the advantages of the previously developed sensors based on target molecules guided formation of AuNP dimers, e.g. the overwhelming sensitivity and stability comparing with those non-oriented sensors based on the formation of large aggregates, with the additional advantages as follows: 1) the target molecules are expanded from oligonucleotides to arbitrary molecules that can specifically bind to aptamers; 2) the color change is completed within 5 min, while the previous sensor based on the formation of AuNP dimers cost ~1 hour to obtain stable responses.