title: Bi-enzyme synergetic catalysis to in situ generate coreactant of peroxydisulfate solution for ultrasensitive electrochemiluminescence immunoassay.
abstract: A novel electrochemiluminescence (ECL) immunosensor for ultrasensitive detection of α-1-fetoprotein (AFP) was designed based on the in situ bi-enzymatic reaction to generate coreactant of peroxydisulfate for signal amplification. In this work, AuNPs were electrodeposited on the glassy carbon electrode (GCE) surface, which promoted the electron transfer. Then, L-cysteine and another layer of AuNPs were, respectively assembled onto the modified electrode surface, which formed the multilayer films for amplifying the ECL signal of peroxydisulfate and immobilizing antibody. At last, glucose oxidase (GOD) and horseradish peroxidase (HRP) were employed to block the nonspecific binding sites. When proper amounts of glucose were added in the detection solution, GOD catalyzed the oxidation of glucose to generate H(2)O(2), which could be further catalyzed by HRP to generate O(2) for the signal amplification. The linear range for AFP detection was 0.001-100 ng mL(-1), with a low detection limit of 3.3 × 10(-4) ng mL(-1). The novel strategy has the advantages of simplicity, sensitivity, good selectivity and reproducibility which might hold a new promise for highly sensitive bioassays applied in clinical detection.
authors.affiliation: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, People's Republic of China.
authors.forename: Haijun
authors.initials: H
authors.lastname: Wang
authors.forename: Ruo
authors.initials: R
authors.lastname: Yuan
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Chai
authors.forename: Huan
authors.initials: H
authors.lastname: Niu
authors.forename: Yaling
authors.initials: Y
authors.lastname: Cao
authors.forename: Huijing
authors.initials: H
authors.lastname: Liu
mesh_terms: D000818:Animals; D055910:Antibodies, Immobilized / Q000737:chemistry* / Q000276:immunology; D015374:Biosensing Techniques / Q000379:methods*; D005949:Glucose Oxidase; D006046:Gold / Q000737:chemistry; D006735:Horseradish Peroxidase; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods*; D008163:Luminescent Measurements / Q000379:methods*; D053768:Metal Nanoparticles / Q000737:chemistry; D012680:Sensitivity and Specificity; D000509:alpha-Fetoproteins / Q000032:analysis* / Q000276:immunology
chemical_list: D055910:Antibodies, Immobilized; D000509:alpha-Fetoproteins; D006046:Gold; D005949:Glucose Oxidase; D006735:Horseradish Peroxidase