An Electrochemiluminescence Biosensor for the Detection of Alzheimer’s Tau Protein Based on Gold Nanostar Decorated Carbon Nitride Nanosheets

Abstract

Human Tau protein is the most reliable biomarker for the prediction of Alzheimer’s disease (AD). However, the assay to detect low concentrations of tau protein in serum is a great challenge for the early diagnosis of AD. This paper reports an electrochemiluminescence (ECL) immunosensor for Tau protein in serum samples. Gold nanostars (AuNSs) decorated on carbon nitride nanosheets (AuNS@g-CN nanostructure) show highly strong and stable ECL activity compared to pristine CN nanosheets due to the electrocatalytic and surface plasmon effects of AuNSs. As a result of the strong electromagnetic field at branches, AuNSs showed a better ECL enhancement effect than their spherical counterpart. For the fabrication of a specific immunosensor, immobilized AuNSs were functionalized with a monoclonal antibody specific for Tau protein. In the presence of Tau protein, the ECL intensity of the immunosensor decreased considerably. Under the optimal conditions, this ECL based immunosensor exhibits a dynamic linear range from 0.1 to 100 ng mL−1 with a low limit of detection of 0.034 ng mL−1. The LOD is less than the Tau level in human serum; thus, this study provides a useful method for the determination of Tau. The fabricated ECL immunosensor was successfully applied to the detection of Tau, the biomarker in serum samples. Therefore, the present approach is very promising for application in diagnosing AD within the early stages of the disease.

Carbon Nitride Nanomaterials: Properties, Synthetic Approaches and New Insights in Fluorescence Spectrometry for Assaying of Metal Ions, Organic and Biomolecules

“…[59] Roghayeh and colleagues recently synthesised g-CNNSs using water as an exfoliation liquid. [60] This approach offers several advantages, including a wide surface area, good crystallinity, and the use of water, a green solvent. [60] However, it has a few drawbacks such as high cost, low yield, and a time-consuming procedure.…”

“…Because of their high stability, increased photo‐absorption, photo‐response, large surface area and non‐toxicity, the as‐prepared g‐CNNSs were employed as efficient, quick, selective, and sensitive photoelectrochemical detection of Cu 2+ in the aqueous environment [59] . Roghayeh and colleagues recently synthesised g‐CNNSs using water as an exfoliation liquid [60] . This approach offers several advantages, including a wide surface area, good crystallinity, and the use of water, a green solvent [60] .…”

Boron carbon nitride nanosheets in water and wastewater treatment: A critical review

“…However, the low adsorption performance and high synthesis cost of these materials have forced researchers to develop novel carbon-based electrode materials [108,109]. Owing to their unique features, BCN nanosheets have been extensively studied in the fields of batteries [110], catalysis [71,111], absorption [112], and supercapacitors [113]. Since carbonbased supercapacitors and CDI processes have a similar principle, BCN could be suitable for CDI electrodes owing to its superior capacitive efficiency [114][115][116].…”

Development of a label-free electrochemiluminescence biosensor for the sensitive detection of porcine gelatin using carbon nanostructured materials

“…24,25 Moreover, the incorporation of different carbon-based nanomaterials has also aided the trend of using ECL methods in developing nano-biosensors. 26,27 The core mechanism of an ECL-based biosensor depends on the interaction between the luminophore and the target protein or antigen. 28 Hence, it is extremely important to use a reliable luminophore and co-reactant mixture to ensure stable and reproducible ECL signals, which get amplified by nanostructured materials.…”