title: Highly sensitive and selective electrochemiluminescence determination of cholesterol utilizing a functional electrode with a core-shell nanostructure.
abstract: A highly sensitive and selective method for the determination of cholesterol is required to evaluate trace amounts of cholesterol in test samples. In this work, selected gold nanoparticles (AuNPs) and 5-amino-2-mercapto-1,3,4-thiadiazole (AMT) were used and a thin film of three-dimensional gold-AMT core-shell nanoparticles (p-AMT-AuNPs) was prepared using an electrochemical method. Cholesterol oxidase was then bonded to the film surface to give a functional electrode. Based on catalysis by the electrode functionalized for cholesterol and a luminol-H2 O2 electrochemiluminescence (ECL) system, a highly sensitive and selective ECL method was developed for the determination of cholesterol. Under optimized conditions, ECL intensity showed a good linear relationship with cholesterol over the concentration range 0.05-11.0 µg/ml, with a correlation coefficient of 0.999 and a limit of detection of 0.02 µg/ml. The proposed method was used to determine cholesterol in dairy products with a relative standard deviation of < 1.8% and recovery rates of 98.1-104%.
authors.affiliation: College of Chemistry & Molecular Engineering, Qingdao University of Science & Technology, Qingdao, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.affiliation: College of Chemistry & Molecular Engineering, Qingdao University of Science & Technology, Qingdao, China.
authors.forename: Junying
authors.initials: J
authors.lastname: Ge
authors.affiliation: College of Chemistry & Molecular Engineering, Qingdao University of Science & Technology, Qingdao, China.
authors.forename: Changzhi
authors.initials: C
authors.lastname: Zhao
mesh_terms: D002784:Cholesterol / Q000032:analysis*; D003611:Dairy Products / Q000032:analysis; D055664:Electrochemical Techniques / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D005504:Food Analysis / Q000295:instrumentation / Q000379:methods; D006046:Gold / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D008163:Luminescent Measurements / Q000295:instrumentation / Q000379:methods*; D008165:Luminol / Q000737:chemistry; D057145:Nanoshells / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013830:Thiadiazoles / Q000737:chemistry
chemical_list: D004800:Enzymes, Immobilized; D013830:Thiadiazoles; D008165:Luminol; D006046:Gold; D002784:Cholesterol; C000592181:2-amino-5-mercapto-1,3,4-thiadiazole
keywords: 5-amino-2-mercapto-1,3,4-thiadiazole; Au nanoparticles; cholesterol; core-shell nanoparticles; electrochemiluminescence