Glutathione regulation-based dual-functional upconversion sensing-platform for acetylcholinesterase activity and cadmium ions.
A dual-functional platform for the sensing of acetylcholinesterase (AChE) activity and cadmium ions (Cd2+) was developed based on the fluorescence resonance energy transfer (FRET) between NaYF4:Yb,Er upconversion nanoparticles (UCNPs) and gold nanoparticles (AuNPs) via glutathione regulation. The detection mechanism is based on the fact that AuNPs can quench the fluorescence of UCNPs. AChE catalyzes the hydrolysis of acetylthiocholine (ATC) into thiocholine which reacts with AuNPs by S-Au conjunction and results the aggregation of AuNPs and change in fluorescence of UCNPs. Therefore, the AChE activity can be detected through the changes of the color of solution and fluorescence recovery of UCNPs. However, the presence of glutathione (GSH) can protect AuNPs from aggregation and enlarge the inter-particle distance between AuNPs and UCNPs. When Cd2+is added into the stable mixture of AuNPs, GSH and AChE/ATC, Cd2+could interact with GSH to form a spherical shaped (GSH)4Cd complex, which decreases the free GSH on the surface of AuNPs to weaken the stability of AuNPs and lead to the easily aggregation of them in the system. The aggregated-AuNPs are released from the surface of UCNPs, which results in the fluorescence of UCNPs gradually recovered. Under the optimized conditions, the detection limits of AChE activity and Cd2+are estimated to be 0.015mU/mL and 0.2µM, respectively. The small molecules regulated dual-functional platform based on UCNPs/AuNPs is a simple, label-free method and can be applied for the turn-on fluorescence detection of AChE activity in human serum and Cd2+in real water samples. The present work demonstrates a general strategy for the design of small molecules regulated multifunctional platform and will be expanded for different areas in the future.
Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China.
Aijin
A
Fang
Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China.
Hongyu
H
Chen
Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China.
Haitao
H
Li
Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China. Electronic address: liumeilingww@126.com.
Meiling
M
Liu
Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China. Electronic address: zhangyy@hunnu.edu.cn.
Youyu
Y
Zhang
Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China.
Shouzhuo
S
Yao
D000110:Acetylcholinesterase / Q000097:blood*; D015374:Biosensing Techniques / Q000379:methods; D002104:Cadmium / Q000032:analysis*; D005063:Europium / Q000737:chemistry; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D005459:Fluorides / Q000737:chemistry; D005978:Glutathione / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006801:Humans; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D014867:Water / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*; D015018:Ytterbium / Q000737:chemistry; D015019:Yttrium / Q000737:chemistry
D028581:Lanthanoid Series Elements; D014874:Water Pollutants, Chemical; C525362:sodium yttriumtetrafluoride; D002104:Cadmium; D014867:Water; D005063:Europium; D015019:Yttrium; D006046:Gold; D000110:Acetylcholinesterase; D005978:Glutathione; D015018:Ytterbium; D005459:Fluorides
Dual-functional platform; Fluorescence resonance energy transfer; Glutathione regulation; Gold nanoparticles; Upconversion nanoparticles