DNA Biosensor Based on Double-Layer Discharge for the Detection of HPV Type 16

• Published in: Sensors (Basel, Switzerland) Switzerland), 2019-09, Vol.19 (18), p.3956
• Main Authors: Espinosa, José R, Galván, Marisol, Quiñones, Arturo S, Ayala, Jorge L, Durón, Sergio M
• Format: Article
• Language: English
• Subjects: Base Sequence; Biopsy; Biosensing Techniques - methods; Biosensors; Charge transfer; Computer simulation; Deoxyribonucleic acid; DNA; DNA, Viral - analysis; DNA/Au electrode equivalent circuit; double layer discharge; electrochemical HPV-16 DNA biosensor; Electrochemical impedance spectroscopy; Electrochemistry; Electrodes; Equivalent circuits; Human papillomavirus; Human papillomavirus 16 - isolation & purification; Hybridization; Methods; Oxidation-Reduction; Peptides; potential relaxation; Sensors; Spectrum analysis
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s19183956

DNA electrochemical biosensors represent a feasible alternative for the diagnosis of different pathologies. In this work, the development of an electrochemical method for Human Papillomavirus-16 (HPV-16) sensing is reported based on potential relaxation measurements related to the discharge of a complex double layer of a DNA-modified gold electrode. The method used allows us to propose an equivalent circuit (EC) for a DNA/Au electrode, which was corroborated by electrochemical impedance spectroscopy (EIS) measurement. This model differs from the Randles circuit that is commonly used in double-layer simulations. The change in the potential relaxation and associated charge transfer resistance were used for sensing the DNA hybridization by using the redox pair Fe(CN) /Fe(CN) as an electrochemical indicator. In order to determinate only the potential relaxation of the composed double layer, the faradic and double-layer current contributions were separated using a rectifier diode arrangement. A detection limit of 0.38 nM was obtained for the target HPV-16 DNA sequences. The biosensor showed a qualitative discrimination between a single-base mismatched sequence and the fully complementary HPV-16 DNA target. The results indicate that the discharge of the double-layer detection method can be used to develop an HPV DNA biosensor.