A fluorometric assay for alkaline phosphatase activity based on β-cyclodextrin-modified carbon quantum dots through host-guest recognition.
A convenient, reliable and highly sensitive assay for alkaline phosphatase (ALP) activity in the real-time manner is developed based on β-cyclodextrin-modified carbon quantum dots (β-CD-CQDs) nanoprobe through specific host-guest recognition. Carbon quantum dots were first functionalized with 3-aminophenyl boronic acid to produce boronic acid-functionalized CQDs, and then further modified with hydropropyl β-cyclodextrins (β-CD) through B-O bonds to form β-CD-CQDs nanoprobe. p-Nitrophenol phosphate disodium salt is used as the substrate of ALP, and can hydrolyze to p-nitrophenol under the catalysis of ALP. The resulting p-nitrophenol can enter the cavity of β-CD moiety in the nanoprobe due to their specific host-guest recognition, where photoinduced electron transfer process between p-nitrophenol and CQDs takes place to efficiently quench the fluorescence of the probe. The correlation between quenched fluorescence and ALP level can be used to establish quantitative evaluation of ALP activity in a broad range from 3.4 to 100.0U/L with the detection limit of 0.9U/L. This assay shows a high sensitivity to ALP even in the presence of a very high concentration of glucose. This study demonstrates a good electron donor/acceptor pair, which can be used to design general detection strategy through PET process, and also broadens the application of host-guest recognition for enzymes detection in clinical practice.
['Tang|Cong|C|', 'Qian|Zhaosheng|Z|', 'Huang|Yuanyuan|Y|', 'Xu|Jiamin|J|', 'Ao|Hang|H|', 'Zhao|Meizhi|M|', 'Zhou|Jin|J|', 'Chen|Jianrong|J|', 'Feng|Hui|H|']
D000469:Alkaline Phosphatase D000818:Animals D015374:Biosensing Techniques D002244:Carbon D002417:Cattle D057075:Enzyme Assays D005470:Fluorometry D057230:Limit of Detection D009596:Nitrophenols D009943:Organophosphorus Compounds D045663:Quantum Dots D047392:beta-Cyclodextrins
Carbon quantum dots Alkaline phosphatase (ALP) activity Photoinduced electron transfer (PET) Real-time fluorometric assay