title: 1,4-Benzenediboronic-Acid-Induced Aggregation of Gold Nanoparticles: Application to Hydrogen Peroxide Detection and Biotin-Avidin-Mediated Immunoassay with Naked-Eye Detection.
abstract: Hydrogen-peroxide (H2O2)-induced growth of small-sized gold nanoparticles (AuNPs) is often implemented for H2O2 sensing and plasmonic immunoassay. In contrast, there is little-to-no information in the literature regarding the application of H2O2-inhibited aggregation of citrate-capped AuNPs. This study discloses that benzene-1,4-diboronic acid (BDBA) was effective in driving the aggregation of citrate-capped AuNPs through an interaction between α-hydroxycarboxylate of citrate and boronic acids of BDBA. The H2O2-mediated oxidation of BDBA resulted in the conversion of boronic acid groups to phenol groups. The oxidized BDBA was incapable of triggering the aggregation of citrate-capped AuNPs. Thus, the presence of H2O2 prohibited BDBA-induced aggregation of citrate-capped AuNPs. The BDBA-induced aggregation of citrate-capped AuNPs can be paired with the glucose oxidase (GOx)-glucose system to design a colorimetric probe for glucose. Moreover, a H2O2·BDBA·AuNP probe was integrated with sandwich immunoassay, biotinylated antibody, and avidin-conjugated GOx for the selective naked-eye detection of rabbit immunoglobulin G (IgG) and human-prostate-specific antigen (PSA). The lowest detectable concentrations of rabbit IgG and human PSA by the naked eye were down to 0.1 and 4 ng/mL, respectively. More importantly, the proposed plasmonic immunoassay allowed the naked-eye quantification of 0-10 ng/mL PSA at an interval of 2 ng/mL in plasma samples.
authors.affiliation: Department of Chemistry, National Sun Yat-sen University , Kaohsiung 80424, Taiwan.
authors.forename: Ya-Chun
authors.initials: YC
authors.lastname: Yang
authors.affiliation: Department of Chemistry, National Sun Yat-sen University , Kaohsiung 80424, Taiwan.|School of Pharmacy, College of Pharmacy, Kaohsiung Medical University , Kaohsiung 80708, Taiwan.|Center for Nanoscience and Nanotechnology, National Sun Yat-sen University , Kaohsiung 80424, Taiwan.
authors.forename: Wei-Lung
authors.initials: WL
authors.lastname: Tseng
mesh_terms: D001360:Avidin / Q000737:chemistry / Q000378:metabolism; D001710:Biotin / Q000737:chemistry / Q000378:metabolism; D001897:Boronic Acids / Q000737:chemistry*; D019343:Citric Acid / Q000737:chemistry; D003124:Colorimetry; D005947:Glucose / Q000032:analysis; D005949:Glucose Oxidase / Q000737:chemistry / Q000378:metabolism; D006046:Gold / Q000737:chemistry*; D006801:Humans; D006861:Hydrogen Peroxide / Q000032:analysis; D007118:Immunoassay / Q000379:methods*; D007074:Immunoglobulin G / Q000276:immunology; D053768:Metal Nanoparticles / Q000737:chemistry*; D017430:Prostate-Specific Antigen / Q000097:blood*
chemical_list: D001897:Boronic Acids; D007074:Immunoglobulin G; D001360:Avidin; D019343:Citric Acid; D001710:Biotin; D006046:Gold; D006861:Hydrogen Peroxide; D005949:Glucose Oxidase; D017430:Prostate-Specific Antigen; D005947:Glucose