Amplified voltammetric detection of glycoproteins using 4-mercaptophenylboronic acid/biotin-modified multifunctional gold nanoparticles as labels

Abstract

Ultrasensitive detection of protein biomarkers is essential for early diagnosis and therapy of many diseases. Glycoproteins, differing from other types of proteins, contain carbohydrate moieties in the oligosaccharide chains. Boronic acid can form boronate ester covalent bonds with diol-containing species. Herein, we present a sensitive and cost-effective electrochemical method for glycoprotein detection using 4-mercaptophenylboronic acid (MBA)/biotin-modified gold nanoparticles (AuNPs) (MBA-biotin-AuNPs) as labels. To demonstrate the feasibility and sensitivity of this method, recombinant human erythropoietin (rHuEPO) was tested as a model analyte. Specifically, rHuEPO was captured by the anti-rHuEPO aptamer-covered electrode and then derivatized with MBA-biotin-AuNPs through the boronic acid–carbohydrate interaction. The MBA-biotin-AuNPs facilitated the attachment of streptavidin-conjugated alkaline phosphatase for the production of electroactive p-aminophenol from p-aminophenyl phosphate substrate. A detection limit of 8 fmol L −1 for rHuEPO detection was achieved. Other glycosylated and non-glycosylated proteins, such as horseradish peroxidase, prostate specific antigen, metallothionein, streptavidin, and thrombin showed no interference in the detection assay.

Biosensors with Boronic Acid-Based Materials as the Recognition Elements and Signal Labels

“…Enzymatic reactions have been well combined with redox cycling for signal amplification [ 118 ]. Boronic acid derivatives and enzymes can be simultaneously loaded on the surface of nanomaterials.…”

“…The oxidized p-AP could be cycled by the reducing reagent tris(2-carboxyethyl)phosphine (TCEP), thus enabling an increase in the anodic current. Enzymatic reactions have been well combined with redox cycling for signal amplification [118]. Boronic acid derivatives and enzymes can be simultaneously loaded on the surface of nanomaterials.…”

“…Nanomaterials with enzyme-like characteristics (nanozymes) can be used as substitutes for natural enzymes to promote the sensing performance of electrochemical bio- Enzymatic reactions have been well combined with redox cycling for signal amp fication [118]. Boronic acid derivatives and enzymes can be simultaneously loaded on t surface of nanomaterials.…”