Electrochemical Aptasensor of Carcinoembryonic Antigen Based on Concanavalin A-Functionalized Magnetic Copper Silicate Carbon Microtubes and Gold-Nanocluster-Assisted Signal Amplification

Abstract

An ultrasensitive electrochemical sensor was developed for the quantitative determination of carcinoembryonic antigen (CEA), which is often utilized as a tumor marker and a prognostic indicator. In the paper, first, copper silicate integrated with nitrogen-doped magnetic carbon microtubes (NCMTs@ Fe 3 O 4 @Cusilicate) was synthesized and employed to enrich concanavalin A (ConA), which can be used as an affinity probe to selectively capture CEA. Through chemical chelation between a copper ion and Con A, the combination of Cusilicate/ConA was greatly improved. Furthermore, gold nanoclusters (AuNCs) immobilized with aptamers were provided for signal amplification. Thus, in the presence of the target protein, CEA, in a sandwich manner, was formed, and AuNCs were gathered on the electrode through a magnetic field. Electrochemical oxidation of AuNCs to AuCl 4 − was performed, and immediately differential pulse voltammetry was performed, resulting in an electrochemical response because of the reduction of AuCl 4 − . On the basis of these merits, the constructed sensing system provided a ultrasensitive detection scheme for CEA with a linear range from 0.03 to 6.00 ng•mL −1 and a low detection limit of 5.38 pg•mL −1 . In addition, the proposed strategy was employed to detect CEA in serum, which showed excellent correlations with standard immunoassay. The excellent performance indicated that the proposed sensor has significant potential for clinical diagnosis.

Metal Nanoparticles for Electrochemical Sensing: Progress and Challenges in the Clinical Transition of Point-of-Care Testing

“…MNPs have superior efficiency as tags or labels for amplifying biomolecular interactions and as the enhancers of electrochemical signals [ 198 , 199 , 200 , 201 , 202 , 203 ]. Depending upon the complexity and necessities, mono/bi/tri-metallic composites are utilized for constructing different types of ECBs with label-free or labeled, sandwich or non-sandwich strategies for CEA immunosensor/aptasensor [ 195 , 196 , 199 , 207 , 210 ]. In mono-metallic-based ECBs, the primary concern is to enhance electrocatalytic surface area for anchoring biomolecules such as the antibody, and labeling enzymes or conductive dyes or biomolecules for developing labeled immunosensors [ 197 , 201 ].…”

Facile strategy for the synthesis of silver nanoparticles on magnetic Fe3O4@C core–shell nanocomposites and their application in catalytic reduction

“…6–8 Notably, the magnetic composites facilitate the recovery to avoid the waste of materials and the possible ecological risk caused by the release of noble NPs into the environment. 9,10 Ag NPs have been combined with magnetic nanomaterials to fabricate magnetic nanocomposites. 11,12 However, as the magnetic nanocomposites were usually directly utilized as the support, uncontrollable growth of nanoparticles occur.…”

Rapid Preparation of Fluorescent Carbon Dots from Pine Needles for Chemical Analysis

“…The detection limits of CEA and TNF-α were 3.1 pg mL −1 and 2.8 pg mL −1 , respectively. Table 1 presents a comparison of the detection limit and linear range obtained herein and in other studies [ 20 , 21 , 22 , 23 , 24 , 25 , 26 ]. The table contains one calorimetric method [ 25 ], two nanoparticle methods [ 20 , 23 ], and four electrochemical methods [ 21 , 22 , 24 , 26 ] from recent literature for comparison.…”

“…Table 1 presents a comparison of the detection limit and linear range obtained herein and in other studies [ 20 , 21 , 22 , 23 , 24 , 25 , 26 ]. The table contains one calorimetric method [ 25 ], two nanoparticle methods [ 20 , 23 ], and four electrochemical methods [ 21 , 22 , 24 , 26 ] from recent literature for comparison. The present method has a lower detection limit and wider linear range for CEA and TNF-α than do the compared approaches.…”