High-sensitivity small-molecule detection of microcystin-LR cyano-toxin using a terahertz-aptamer biosensor
| Autor: | Ahmed Mohamed, Mohamed Cherif, Jonathan Perreault, Xavier Ropagnol, Hassan A. Hafez, François Vidal, Ryan Walsh, Tsuneyuki Ozaki |
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| Rok vydání: | 2021 |
| Předmět: |
Materials science
Microcystins Silicon Terahertz radiation Aptamer Analytical chemistry chemistry.chemical_element Biosensing Techniques 02 engineering and technology 01 natural sciences Biochemistry Analytical Chemistry Limit of Detection Electrochemistry Environmental Chemistry Surface plasmon resonance Spectroscopy Detection limit 010401 analytical chemistry Silicon Dioxide 021001 nanoscience & nanotechnology Small molecule 0104 chemical sciences chemistry Click chemistry Marine Toxins 0210 nano-technology Biosensor |
| Zdroj: | The Analyst. 146:7583-7592 |
| ISSN: | 1364-5528 0003-2654 |
| DOI: | 10.1039/d1an01577j |
| Popis: | We demonstrate the rapid and highly sensitive detection of a small molecule, microcystin-LR (MC-LR) toxin using an aptasensor based on a terahertz (THz) emission technique named the terahertz chemical microscope (TCM). The main component of the TCM is the sensing plate, which consists of a thin silicon layer deposited on a sapphire substrate, with a natural SiO2 layer formed on the top of the Si layer. The DNA aptamer is linked to the oxidized top surface of the silicon layer by a one-step reaction (click chemistry) between the DBCO-labeled aptamer and an azido group that binds to the surface. Using density functional theory (DFT) calculations, the number of active sites on the surface has been estimated to be 3.8 × 1013 cm-2. Aptamer immobilization and MC-LR binding have been optimized by adjusting the aptamer concentration and the binding buffer composition. When MC-LR binds with the DNA aptamer, it causes a change in the chemical potential at the surface of the sensing plate, which leads to a change in the amplitude of the THz signal. Compared with other bio-sensing methods such as surface plasmon resonance (SPR), TCM is a rapid assay that can be completed in 15 min (10 min incubation and 5 min data acquisition). Moreover, our results show that the aptamer-based TCM can detect MC-LR with an excellent detection limit of 50 ng L-1, which is 20 times more sensitive compared with SPR measurements of MC-LR. |
| Databáze: | OpenAIRE |
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