An electrochemical aptasensor for Δ9-tetrahydrocannabinol detection in saliva on a microfluidic platform.
Biosens Bioelectron
; 222: 114998, 2023 Feb 15.
Article
em En
| MEDLINE
| ID: mdl-36549107
ABSTRACT
We present a novel "on-off", cost-effective, rapid electrochemical aptasensor combined with a microfluidics cartridge system for the detection of Δ9-THC (Δ9-tetrahydrocannabinol) in human saliva via differential pulse voltammetry. The assay relied on the competitive binding between the Δ9-THC and a soluble redox indicator methylene blue, using an aptamer selected via FRELEX. We found that the aptasensor can detected 1 nM of Δ9-THC in PBS in a three-electrode cell system, while the sensitivity and both the dissociation constant (Kd) and association constant (Kb) were dependent on the aptamer density. The aptamer also showed great affinity towards Δ9-THC when tested against cannabinol and cannabidiol. The same limit of detection of 1 nM in PBS was achieved in small volume samples (â¼60 µL) using the aptamer-modified gold screen-printed electrodes combined with the microfluidic cartridge setup, however, the presence of 10% raw human saliva had a negative effect which manifested in a 10-fold increase in the LOD due to interfering elements. Filtering the saliva, improved the tested volume to 50% and the LOD to 5 nM of Δ9-THC which is lower than the concentrations associated with impairment (6.5-32 nM). The aptasensor showed a good storage capability up to 3 days, however, the reusability significantly dropped from 10 cycles (freshly prepared) to 5 cycles. The results clearly demonstrate the feasibility of the aptasensor platform with the microfluidics chamber towards a point-of-care testing application for the detection of Δ9-THC in saliva.
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Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Técnicas Biossensoriais
/
Aptâmeros de Nucleotídeos
Tipo de estudo:
Diagnostic_studies
Limite:
Humans
Idioma:
En
Revista:
Biosens Bioelectron
Assunto da revista:
BIOTECNOLOGIA
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
Canadá