Electrochemical aptasensor for NS1 detection: Towards a fast dengue biosensor

• Published in: Talanta (Oxford) 2021-10, Vol.233, p.122527-122527, Article 122527
• Main Authors: Bachour Junior, Bassam, Batistuti, Marina Ribeiro, Pereira, Aline Sanches, de Sousa Russo, Elisa Maria, Mulato, Marcelo
• Format: Article
• Language: English
• Subjects: Aptamer; Biosensor; Dengue; Impedimetric; NS1
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2021.122527

Dengue is one of the most commonly neglected tropical diseases transmitted by Aedes aegypti infected with Dengue virus. This virus belongs to the gender Flavivirus and produces a non-structural protein 1 (NS1), which is an important biomarker found at high levels in blood in early disease stage. Therefore, this study focused on the development of an electrochemical biosensor for NS1 detection using DNA aptamers. Gold electrodes were co-immobilized with specific aptamers and 6-mercapto-1-hexanol (MCH) to obtain a self-assembled monolayer. The molar ratio between aptamers and MCH was optimized and the platform characterized by electrochemical impedance spectroscopy and atomic force microscopy. Bovine serum albumin was added in NS1 solution to stabilize it and block the surface to avoid non-specific interactions. The biosensor performance was tested with NS1 protein serotype 4 (in phosphate saline buffer and human serum) and with a solution of serotype 1 in human serum. The results showed a sensitivity of 2.9%, 2.7% and 1.7% per decade, respectively, and low limit of detection (0.05, 0.022 and 0.025 ng/mL). The platform was also tested with Envelope protein as negative control. Furthermore, the aptamer sensor was able to detect NS1 in clinical range and it is a promising candidate for a new class for miniaturized point-of-care device for different Dengue serotypes. [Display omitted] •An electrochemical biosensor for Dengue detection using DNA aptamers.•Surface characterization through AFM and electrochemical impedance spectroscopy.•Biosensor identify NS1 serotype 1 and 4 in undiluted human serum in clinical range.•Platform provided 22 pg/mL as LOD with a linear range from 10 pg to 1 μg/mL.•Aptasensor was tested with E protein as negative control and show a high selectivity.