title: Sensitive and selective determining ascorbic acid and activity of alkaline phosphatase based on electrochemiluminescence of dual-stabilizers-capped CdSe quantum dots in carbon nanotube-nafion composite.
abstract: Sensitive and selective determining bio-related molecule and enzyme play an important role in designing novel procedure for biological sensing and clinical diagnosis. Herein, we found that dual-stabilizers-capped CdSe quantum dots (QDs) in composite film of multi-walled carbon nanotubes (CNTs) and Nafion, displaying eye-visible monochromatic electrochemiluminescence (ECL) with fwhm of 37nm, which offers promising ECL signal for detecting ascorbic acid (AA) as well as the activity of alkaline phosphatase (ALP) in biological samples. It was also shown that the dual-stabilizers-capped CdSe QDs can preserve their highly passivated surface states with prolonged lifetime of excited states in Nafion mixtures, and facilitate electron-transfer ability of Nafion film along with CNTs. Compared with the QDs/GCE, the ECL intensity is enhanced 1.8 times and triggering potential shifted to lower energy by 0.12V on the CdSe-CNTs-Nafion/GCE. The ECL quenching degree increases with increasing concentration of AA in the range of 0.01-30nM with a limit of detection (LOD) of 5pM. The activity of ALP was determined indirectly according to the concentration of AA, generated in the hydrolysis reaction of l-ascorbic acid 2-phosphate sesquimagnesium (AA-P) in the presence of ALP as a catalyst, with an LOD of 1μU/L. The proposed strategy is favorable for developing simple ECL sensor or device with high sensitivity, spectral resolution and less electrochemical interference.
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan 250014, PR China.
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Ma
authors.affiliation: College of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, PR China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan 250014, PR China.
authors.forename: Xinli
authors.initials: X
authors.lastname: Guo
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan 250014, PR China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Kang
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan 250014, PR China. Electronic address: dzshen@sdnu.edu.cn.
authors.forename: Dazhong
authors.initials: D
authors.lastname: Shen
authors.affiliation: College of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, PR China. Electronic address: zouguizheng@sdu.edu.cn.
authors.forename: Guizheng
authors.initials: G
authors.lastname: Zou
mesh_terms: D000469:Alkaline Phosphatase; D001205:Ascorbic Acid; D019187:Cadmium Compounds; D005465:Fluorocarbon Polymers; D008163:Luminescent Measurements; D037742:Nanotubes, Carbon; D045663:Quantum Dots; D018036:Selenium Compounds
chemical_list: D019187:Cadmium Compounds; D005465:Fluorocarbon Polymers; D037742:Nanotubes, Carbon; D018036:Selenium Compounds; C040402:perfluorosulfonic acid; C058667:cadmium selenide; D000469:Alkaline Phosphatase; D001205:Ascorbic Acid
keywords: Alkaline phosphatase; Ascorbic acid; CdSe Quantum dots; Electrochemiluminescence