Water-soluble gold nanoclusters prepared by protein-ligand interaction as fluorescent probe for real-time assay of pyrophosphatase activity.
This paper reports a new and facile method for the synthesis of water-soluble thiolate-protected AuNCs via protein-ligand interaction. Using 3-mercaptopropionic acid (MPA) as a model ligand and bovine serum albumin (BSA) as a model protein, water-soluble AuNCs (BSA/MPA-AuNCs) with intense orange-yellow fluorescent emission (quantum yield=16%) are obtained. Results show that AuNCs produced with this method have hydrophobic interactions with BSA. The synthetic strategy is then successfully extended to produce water-soluble AuNCs protected by other thiolates. Moreover, a sensitive and eco-friendly sensing system is established for detection of the activity of inorganic pyrophosphatase (PPase), which relies on the selective coordination of Fe(3+)with BSA/MPA-AuNCs, the higher affinity between pyrophosphate (PPi) and Fe(3+), and the hydrolysis of PPi by PPase. A good linearity between the fluorescence intensity and PPase activity within the range from 0.1 to 3U/L is found, with a detection limit down to 0.07U/L. Additionally, the fluorescent assay developed here is utilized to assay the PPase activity in real biological samples and as well as to evaluate PPase inhibitor, illustrating the great potential for biological analysis.
Department of Pharmaceutical Analysis, Fujian Medical University, Fuzhou 350004, China.
Hao-Hua
HH
Deng
Department of Pharmaceutical Analysis, Fujian Medical University, Fuzhou 350004, China.
Fei-Fei
FF
Wang
Department of Pharmaceutical Analysis, Fujian Medical University, Fuzhou 350004, China.
Xiao-Qiong
XQ
Shi
Department of Pharmaceutical Analysis, Fujian Medical University, Fuzhou 350004, China.
Hua-Ping
HP
Peng
Department of Pharmaceutical Analysis, Fujian Medical University, Fuzhou 350004, China.
Ai-Lin
AL
Liu
State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
Xing-Hua
XH
Xia
Department of Pharmaceutical Analysis, Fujian Medical University, Fuzhou 350004, China. Electronic address: chenandhu@163.com.
Wei
W
Chen
D015097:3-Mercaptopropionic Acid / Q000737:chemistry; D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D002417:Cattle; D011756:Diphosphates / Q000378:metabolism; D057075:Enzyme Assays / Q000379:methods; D005456:Fluorescent Dyes / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D043564:Inorganic Pyrophosphatase / Q000032:analysis / Q000378:metabolism*; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D012710:Serum Albumin, Bovine / Q000737:chemistry; D012995:Solubility; D013050:Spectrometry, Fluorescence / Q000379:methods; D014867:Water / Q000737:chemistry
D011756:Diphosphates; D005456:Fluorescent Dyes; D014867:Water; D012710:Serum Albumin, Bovine; C107241:diphosphoric acid; D006046:Gold; D015097:3-Mercaptopropionic Acid; D043564:Inorganic Pyrophosphatase
Fluorescence; Gold nanoclusters; Protein-ligand interaction; Pyrophosphatase; Thiolate