Glucose oxidase-encapsulated nanogold hollow microspheres as labels based on a sensitive electroluminescent immunoassay

Abstract

We herein report the synthesis of glucose oxidase-encapsulated nanogold hollow microspheres (GOx-GHS), which show excellent catalytic performance for the reduction reaction of glucose, and the nanogold on the GOx-GHS provided the nanoparticles with good biocompatibility. In addition, the electrochemiluminescence (ECL) property of luminol was investigated and a type of luminol nanocomposite (AuNPs-EGN-luminol) was prepared. The as-prepared nano-composite was found to have good ECL property of the luminol, as well as good electroconductibility. The prepared GOx-GHS and AuNPs-EGN-luminol were applied in a sandwich-type ECL immunosensor for cancer antigen 125 (CA125). In the immunosensor, AuNPs-EGN-luminol acted as a solid support for CA125 primary antibody, and GOx-GHS was employed as the supporter of CA 125 secondary antibody. With the addition of glucose, the hydrogen peroxide was prepared and the ECL property of the AuNPs-EGNluminol was enhanced. The proposed immunosensor enabled CA125 concentrations to be determined in the range of 1 pg mL À1 to 100 ng mL À1 , with a detection limit of 0.38 pg mL À1 .

A sensitive electrochemiluminescence immunosensor for carbohydrate antigen 12-5 analysis based on dual-function SnO2 nanoflowers

“…Wang's group designed a sandwich-type ECL immunosensor for determining the CA12-5 level using luminol nanocomposites (AuNPs-EGN-Luminol) labeling Ab 1 as the signal probe and glucose oxidase-encapsulated nano-gold hollow microspheres (GOx-GHS) as a sensing platform for fixing Ab 2 . 21…”

“…Wang's group designed a sandwich-type ECL immunosensor for determining the CA12-5 level using luminol nanocomposites (AuNPs-EGN-Luminol) labeling Ab 1 as the signal probe and glucose oxidase-encapsulated nanogold hollow microspheres (GOx-GHS) as a sensing platform for fixing Ab 2 . 21 Luminol, semiconductor quantum dots (QDs), and Ru(bpy) 3 2+ have been used as a traditional ECL luminophore, which needs a suitable nanocarrier to load itself for improving luminous efficiency. [22][23][24] Still, an efficient ECL luminescent material with excellent electrical conductivity, low toxicity, high stability, and good biocompatibility needs to be developed to assemble immunosensors.…”

A cathodic luminol-based electrochemiluminescence biosensor for detecting cholesterol using 3D-MoS2–PANI nanoflowers and Ag nanocubes for signal enhancement

“…1,2 As is well known, the ECL emission of luminol could be enhanced by reactive oxygen species (ROSs) such as hydroxyl 25 radical (OH • ) and superoxide anion (O 2 • ). 3 Meanwhile, ROSs could be generated from H 2 O 2 , which is exactly the product of many biological active substrates with the catalysis of corresponding enzymes.…”

“…Luminol and its derivatives, as some of the most extensively investigated and used luminophores for electrochemiluminescence (ECL) systems, have attracted considerable attention due to their excellent inherent properties such as non-toxicity, low cost, low oxidation potential and high quantum yield. 1,2 As is well known, the ECL emission of luminol can be enhanced by reactive oxygen species (ROSs) such as hydroxyl radical (OHc) and superoxide anion (O 2 c À ). 3 Moreover, ROSs can be generated from H 2 O 2 , which is the product of many biologically active substrates with the catalysis of corresponding enzymes.…”