title: Highly sensitive electrochemiluminescence biosensors for cholesterol detection based on mesoporous magnetic core-shell microspheres.
abstract: A sensitive electrochemiluminescence (ECL) biosensor for cholesterol detection based on multifunctional core-shell structured microspheres (Fe3O4@SiO2-Au@mpSiO2) is reported. This microsphere consisted of a core of silica-coated magnetite nanoparticle, an active transition layer of gold nanoparticles and a mesoporous silica shell. Scanning electron microscopy was employed to observe the morphology of the nanomaterials and transmission electron microscopy was used to further confirm the subtle structure of Fe3O4@SiO2-Au@mpSiO2. The microspheres possessed a large surface area that increased enzyme loading, and an active transition layer gold nanoparticles enhanced the ECL signal. They were used to immobilize cholesterol oxidase for cholesterol detection with a high sensitivity, low detection limit and wide linear range. The linear range was from 0.83 to 2.62 mM with a detection limit of 0.28 µM (S/N = 3). Moreover, the reproducibility, stability and selectivity of the biosensor were established.
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, People's Republic of China.
authors.forename: Juanjuan
authors.initials: J
authors.lastname: Zhang
authors.forename: Shihong
authors.initials: S
authors.lastname: Chen
authors.forename: Xingrong
authors.initials: X
authors.lastname: Tan
authors.forename: Xia
authors.initials: X
authors.lastname: Zhong
authors.forename: Dehua
authors.initials: D
authors.lastname: Yuan
authors.forename: Yinfeng
authors.initials: Y
authors.lastname: Cheng
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D002784:Cholesterol / Q000032:analysis*; D002789:Cholesterol Oxidase / Q000378:metabolism; D004563:Electrochemistry / Q000379:methods*; D004800:Enzymes, Immobilized / Q000378:metabolism; D049449:Luminescence; D008280:Magnetics; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D008863:Microspheres; D053758:Nanoparticles; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D004800:Enzymes, Immobilized; D002784:Cholesterol; D002789:Cholesterol Oxidase