A DNA Aptasensor for Electrochemical Detection of Vascular Endothelial Growth Factor.
Electrochemical aptasensors can detect different cancer biomarkers to provide point-of-care diagnosis that is low cost, rapid, specific and sensitive. In this work, we described the development of an electrochemical single-use aptasensor for detection and analysis of vascular endothelial growth factor (VEGF). Gold nanostructured graphite screen-printed electrodes were firstly modified with a mixed monolayer of a primary thiolated DNA aptamer and a spacer thiol, 6-mercapto-1-hexanol. VEGF protein was then incubated with the aptasensor. An enzyme-amplified detection scheme, based on the coupling of a streptavidin-alkaline phosphatase conjugate and secondary biotinylated aptamer was then applied. The enzyme catalyzed the hydrolysis of the electroinactive 1 -naphthyl-phosphate to 1 -naphthol; this product is electroactive and has been detected by means of differential pulse voltammetry (DPV). The aptasensor response was found to be linearly related to the target concentration between 0 and 250 nmol L(-1); the detection limit was 30 nmol L(-1). The performance of the immunoassay in terms of reproducibility and selectivity has been also studied.
A
A
Ravalli
L
L
Rivas
Alfredo
A
De la Escosura-Muñiz
J
J
Pons
A
A
Merkoçi
G
G
Marrazza
D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D004247:DNA / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000295:instrumentation / Q000379:methods; D006046:Gold / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D016014:Linear Models; D053768:Metal Nanoparticles / Q000737:chemistry*; D015203:Reproducibility of Results; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis*
D052157:Aptamers, Nucleotide; D042461:Vascular Endothelial Growth Factor A; D006046:Gold; D006108:Graphite; D004247:DNA