title: Sensitive detection of alkaline phosphatase by switching on gold nanoclusters fluorescence quenched by pyridoxal phosphate.
abstract: In this work, we designed highly sensitive and selective luminescent detection method for alkaline phosphatase using bovine serum albumin functionalized gold nanoclusters (BSA-AuNCs) as the nanosensor probe and pyridoxal phosphate as the substrate of alkaline phosphatase. We found that pyridoxal phosphate can quench the fluorescence of BSA-AuNCs and pyridoxal has little effect on the fluorescence of BSA-AuNCs. The proposed mechanism of fluorescence quenching by PLP was explored on the basis of data obtained from high-resolution transmission electron microscopy (HRTEM), dynamic light scattering (DLS), UV-vis spectrophotometry, fluorescence spectroscopy, fluorescence decay time measurements and circular dichroism (CD) spectroscopy. Alkaline phosphatase catalyzes the hydrolysis of pyridoxal phosphate to generate pyridoxal, restoring the fluorescence of BSA-AuNCs. Therefore, a recovery type approach has been developed for the sensitive detection of alkaline phosphatase in the range of 1.0-200.0U/L (R2=0.995) with a detection limit of 0.05U/L. The proposed sensor exhibit excellent selectivity among various enzymes, such as glucose oxidase, lysozyme, trypsin, papain, and pepsin. The present switch-on fluorescence sensing strategy for alkaline phosphatase was successfully applied in human serum plasma with good recoveries (100.60-104.46%), revealing that this nanosensor probe is a promising tool for ALP detection.
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China; Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, University of Mansoura, 35516 Mansoura, Egypt.
authors.forename: Mohamed Ibrahim
authors.initials: MI
authors.lastname: Halawa
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
authors.forename: Wenyue
authors.initials: W
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Saqib
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
authors.forename: Shimeles Addisu
authors.initials: SA
authors.lastname: Kitte
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
authors.forename: Fengxia
authors.initials: F
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, PR China. Electronic address: guobaoxu@ciac.ac.cn.
authors.forename: Guobao
authors.initials: G
authors.lastname: Xu
mesh_terms: D000469:Alkaline Phosphatase / Q000737:chemistry / Q000302:isolation & purification*; D015374:Biosensing Techniques; D005453:Fluorescence; D006046:Gold / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D011732:Pyridoxal Phosphate / Q000737:chemistry; D012710:Serum Albumin, Bovine / Q000737:chemistry; D013050:Spectrometry, Fluorescence
chemical_list: D012710:Serum Albumin, Bovine; D011732:Pyridoxal Phosphate; D006046:Gold; D000469:Alkaline Phosphatase
keywords: Alkaline phosphatase; Bovine serum albumin protected gold nanoclusters; Pyridoxal; Pyridoxal phosphate; Quenching