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Label-Free Homogeneous Electrochemical Aptasensor Based on Size Exclusion/Charge-Selective Permeability of Nanochannel Arrays and 2D Nanorecognitive Probe for Sensitive Detection of Alpha-Fetoprotein
The labeling-free and immobilization-free homogeneous aptamer sensor offers advantages including simple operation, low cost, and high sensitivity, demonstrating great potential in rapid detection of tumor biomarkers in biological samples. In this work, a labeling-free and immobilization-free homogen...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2023
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10574445/ https://www.ncbi.nlm.nih.gov/pubmed/37836778 http://dx.doi.org/10.3390/molecules28196935 |
Sumario: | The labeling-free and immobilization-free homogeneous aptamer sensor offers advantages including simple operation, low cost, and high sensitivity, demonstrating great potential in rapid detection of tumor biomarkers in biological samples. In this work, a labeling-free and immobilization-free homogeneous aptamer sensor was conveniently fabricated by combining size exclusion and charge-selective penetration of a nanochannel-modified electrode and two-dimensional (2D) nanorecognition probe which can realize selective and highly sensitive detection of alpha-fetoprotein (AFP) in serum. Vertically ordered mesoporous silica film (VMSF) with ultra-small, uniform, and vertically aligned nanochannels was easily grown on the simple, low-cost, and disposable indium tin oxide (ITO) electrode. Through π-π interaction and electrostatic force, the AFP aptamer (Apt) and electrochemical probe, tris(bipyridine)ruthenium(II) (Ru(bpy)(3)(2+)), were coloaded onto graphene oxide (GO) through simple incubation, forming a 2D nanoscale recognition probe (Ru(bpy)(3)(2+)/Apt@GO). Owing to the size exclusion effect of VMSF towards the 2D nanoscale probe, the electrochemical signal of Ru(bpy)(3)(2+)/Apt@GO could not be detected. In the presence of AFP, the specific binding of AFP to the aptamer causes the dissociation of the aptamer and Ru(bpy)(3)(2+) from GO, resulting in their presence in the solution. The efficient electrostatic enrichment towards Ru(bpy)(3)(2+) by negatively charged VMSF allows for high electrochemical signals of free Ru(bpy)(3)(2+) in the solution. Linear determination of AFP ranged from 1 pg/mL to 1000 ng/mL and could be obtained with a low limit of detection (LOD, 0.8 pg/mL). The high specificity of the adapter endowed the constructed sensor with high selectivity. The fabricated probe can be applied in direct determination of AFP in serum. |
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