A bimetallic metal-organic framework with high enzyme-mimicking activity for an integrated electrochemical immunoassay of carcinoembryonic antigen

Dual-channel, real-time, long-term stable electrochemical immunosensor based on Au, Cu-vertical graphene for detection of carcinoembryonic antigen in tumor cells

BACKGROUND

The accurate and rapid determination of a broad-spectrum tumor marker, carcinoembryonic antigen (CEA), in tumor cells, human tissues, and body fluids is important for the early diagnosis, drug development, efficacy evaluation, and prognosis tracking of cancer.

RESULTS

In this study, a dual-channel electrochemical immunosensor was designed for the sensitive determination of CEA levels using an Au-AuCu-vertical graphene (VG) sensing platform. An AuCu bimetallic doping strategy was adopted to improve the biocompatibility of graphene with the cells, and Au nanoparticles were electrodeposited to firmly bind numerous CEA antibodies. The immunosensor exhibited a broad limit of linearity from 0.001 to 30000 pg mL-1 and a low limit of detection of 0.28 fg mL-1. This immunosensor exhibited excellent selectivity, reproducibility, and long-term stability. The developed Au-AuCu-VG-based immunosensor pen combined with self-designed electrochemical immunoassay software achieved high-precision real-time on-site analysis of CEA concentrations.

SIGNIFICANCE

The proposed AuCu-VG electrode exhibited antibody-binding ability, inherent probe peak, and excellent binding of the Au NPs. A new dual-channel electrochemical immunoassay strategy was developed based on the AuCu-VG electrode, which could sensitively and reliably detect the real-time concentration of CEA released by tumor cells, such as MCF-7.

Label-free electrochemical immunosensors based on Cu-Ni metal-organic framework and carbon nanotube composite for carcinoembryonic antigen detection

Monitoring cancer biomarkers is of great significance in clinical diagnosis. In this work, a label-free MWCNTs-COOH/CuNi-BTC/FTO electrochemical immunosensor was developed to quantitatively detect carcinoembryonic antigen (CEA). The bimetallic CuNi-BTC showed enhanced current than singe Ni-BTC, and the addition of the MWCNTs-COOH increased the conductivity and further amplified the current signal. The electrode was further modified with CEA antigen (Ag) and bovine serum albumin (BSA) was used to block the non-specific binding sites. Using the emplified current signal of CuNi-BTC, CEA was detected by a DPV method through the current change caused by the specific recognition reaction of Ag and Ab. Under optimal conditions, a range of 0.80-140 ng/mL and a detection limit of 0.046 ng/mL for CEA was obtained. This electrochemical immunosensor possessed good selectivity, reproducibility and long-term stability.

Advances in carcinoembryonic antigen detection: a review of clinical applications and standardization

Carcinoembryonic antigen (CEA) is among the earliest identified tumor markers and remains extensively utilized in the diagnosis and management of colorectal cancer. The detection of CEA presents considerable challenges in the field of analytical chemistry, given its complexity. The most prevalent detection approach is the immunoassay, including the chemiluminescence immunoassay commonly employed in clinical settings; however, discrepancies between various methods persist. Mass spectrometry-based techniques offer enhanced accuracy as they circumvent matrix interference. Nonetheless, the intricate nature of proteins continues to pose significant challenges. This paper reviews recent advancements in CEA detection technologies, examines their clinical application potential from two key platforms, and addresses the standardization process of CEA detection. This paper highlights the importance of developing rapid and precise methods for CEA analysis in complex matrices and their standardization.

Construction of a portable and sensitive electrochemical immunosensor for the rapid detection of erythromycin based on semiconductive bimetallic MOF

The sensitive determination of antibiotics in food products is vital for ensuring food safety and protecting human health. Herein, we have fabricated a novel electrochemical portable and sensitive electrochemical immunosensor for the efficient detection of erythromycin (ERY) containing in food stuffs. For this, a semiconductive cooper/ferric bimetallic metal-organic framework (scMOF), which was synthesized using 2,3,6,7,10,11-hexahydroxytriphenylene (HHTP) as linking ligand (denoted as CuxFe3-x(HHTP)2), was utilized simultaneously as the platform for anchoring antibody and for modifying the sprinted printed electrode (SPE) to construct the electrochemical immunosensor. The obtained scMOF, CuxFe3-x(HHTP)2, exhibited high porosity, promoted conductivity, and enhanced anchoring ability toward antibody. Thereby, the developed SPE immunosensor demonstrated the superior biosensing performance for the detection of ERY. Within a wide range from 1.0 fg mL-1 to 1.0 ng mL-1, the CuxFe3-x(HHTP)2-based portable SPE immunosensor had an ultralow detection limit of 0.69 fg mL-1, together with high selectivity, good reproducibility, and excellent long-term stability, as well as acceptable practicality. The present SPE immunosensor based on scMOFs not only provides an innovative biosensing strategy for the sensitive inspection of antibiotics, but also extends the application of scMOF in the field of food analysis.

Electrochemical protein biosensors for disease marker detection: progress and opportunities

The development of artificial intelligence-enabled medical health care has created both opportunities and challenges for next-generation biosensor technology. Proteins are extensively used as biological macromolecular markers in disease diagnosis and the analysis of therapeutic effects. Electrochemical protein biosensors have achieved desirable specificity by using the specific antibody-antigen binding principle in immunology. However, the active centers of protein biomarkers are surrounded by a peptide matrix, which hinders charge transfer and results in insufficient sensor sensitivity. Therefore, electrode-modified materials and transducer devices have been designed to increase the sensitivity and improve the practical application prospects of electrochemical protein sensors. In this review, we summarize recent reports of electrochemical biosensors for protein biomarker detection. We highlight the latest research on electrochemical protein biosensors for the detection of cancer, viral infectious diseases, inflammation, and other diseases. The corresponding sensitive materials, transducer structures, and detection principles associated with such biosensors are also addressed generally. Finally, we present an outlook on the use of electrochemical protein biosensors for disease marker detection for the next few years.

Recent advancements in the specific determination of carcinoembryonic antigens using MOF-based immunosensors

Carcinoembryonic antigens (CEAs) are prominent cancer biomarkers that enable the early detection of numerous cancers. For effective CEA screening, rapid, portable, efficient, and sensitive diagnosis approaches should be devised. Metal-organic frameworks (MOFs) are porous crystalline materials that have received major attention for application in high-efficiency signal probes owing to their advantages such as large specific surface area, superior chemical stability and tunability, high porosity, easy surface functional modification, and adjustable size and morphology. Immunoassay strategies using antigen-antibody specific interaction are one of the imperative means for rapid and accurate measurement of target molecules in biochemical fields. The emerging MOFs and their nanocomposites are synthesized with excellent features, providing promising potential for immunoassays. This article outlines the recent breakthroughs in the synthesis approaches of MOFs and overall functionalization mechanisms of MOFs with antigen/antibody and their uses in the CEA immunoassays, which operate according to electrochemical, electrochemiluminescent and colorimetric techniques. The prospects and limitations of the preparation and immunoassay applications of MOF-derived hybrid nanocomposites are also discussed at the end.

Artificial enzyme innovations in electrochemical devices: advancing wearable and portable sensing technologies

With the rapid evolution of sensing technologies, the integration of nanoscale catalysts, particularly those mimicking enzymatic functions, into electrochemical devices has surfaced as a pivotal advancement. These catalysts, dubbed artificial enzymes, embody a blend of heightened sensitivity, selectivity, and durability, laying the groundwork for innovative applications in real-time health monitoring and environmental detection. This minireview penetrates into the fundamental principles of electrochemical sensing, elucidating the unique attributes that establish artificial enzymes as foundational elements in this field. We spotlight a range of innovations where these catalysts have been proficiently incorporated into wearable and portable platforms. Navigating the pathway of amalgamating these nanoscale wonders into consumer-appealing devices presents a multitude of challenges; nevertheless, the progress made thus far signals a promising trajectory. As the intersection of materials science, biochemistry, and electronics progressively intensifies, a flourishing future seems imminent for artificial enzyme-infused electrochemical devices, with the potential to redefine the landscapes of wearable health diagnostics and portable sensing solutions.