Simple immunosensor for ultrasensitive electrochemical determination of biomarker of the bone metabolism in human serum

Abstract

Ultrasensitive and selective determination of biomarkers of the bone metabolism in serum is crucial for early screening, timely treatment, and monitoring of the curative effect of osteoporosis, which is a silent disease with serious health threats. Immunoassay with a simple sensing interface and ultrahigh sensitivity is highly desirable. Herein, a simple electrochemical immunosensor is demonstrated based on gold nanoparticles (AuNPs) electrodeposited on chitosan-reduced graphene oxide (CS-G) composite modified electrode, which can achieve sensitive determination of the important biomarker of bone metabolism, bone gamma-carboxyglutamate protein (BGP). To overcome the agglomeration of graphene and introduce a biocompatible matrix with functional amino groups, CS-G is prepared and modified on the supporting glassy carbon electrode (GCE). Then, AuNPs are electrodeposited on CS-G through their interaction between amine groups of CS. The immobilized AuNPs provide numerous binding sites to immobilize anti-BGP antibodies (AbBGP). The specific recognition between BGP and AbBGP results in a reduction in the mass transfer of the electrochemical probe (Fe(CN)63-/4-) in solution, leading to a reduced electrochemical signal. Based on this mechanism, fast and ultrasensitive electrochemical detection of BGP is achieved when the concentration of BGP ranges from 100 ag ml−1 to 10 μg mL−1 with a limit of detection (LOD) of 20 ag ml−1 (S/N = 3). The determination of BGP in human serum is also realized with high reliability.

Disposable Electrochemical Sensors for Highly Sensitive Detection of Chlorpromazine in Human Whole Blood Based on the Silica Nanochannel Array Modified Screen-Printed Carbon Electrode

“…Graphene-based materials (e.g., 0D graphene quantum dots [ 41 , 42 ], 2D graphene nanosheets [ 43 ], and 3D porous graphene [ 44 ]) usually exhibit novel optical/electrical/catalytic properties [ 45 , 46 , 47 , 48 ] and have been widely used to construct various sensing systems with improved analytical performance [ 49 , 50 , 51 ]. Figure 1 a illustrates the fabrication process of VMSF/ErGO/SPCE.…”

Equipment of Vertically-Ordered Mesoporous Silica Film on Electrochemically Pretreated Three-Dimensional Graphene Electrodes for Sensitive Detection of Methidazine in Urine

“…However, these approaches usually need time-consuming and complex sample pretreatment, expensive instruments, and professional operators. In comparison, electrochemical sensors are highly attractive because of their advantages, such as fast detection, convenient operation, cheap instrument, easy integration, and portability [ 11 , 12 , 13 , 14 ]. The combination of functional nanomaterials can further improve detection performance.…”

Electrostatic Nanocage-Confined Probe for Electrochemical Detection of CA19-9 in Human Serum

“…These assays have many advantages but also have some drawbacks, such as large sample volume, complicated and expensive instruments, and limited sensitivity. Recently, electrochemical immunosensors have attracted great interest owing to their features of simple devices, low cost, high sensitivity, and easy miniaturization. − …”