A highly sensitive aptamer-immunoassay for vascular endothelial growth factor coupled with portable glucose meter and hybridization chain reaction

In this paper, coupled with hybridization chain reaction and portable personal glucose meter, a highly sensitive aptamer-based immunoassay for vascular endothelial growth factor (VEGF) is fabricated. The antibody immobilized on the microplate captured the target protein, which would be sandwiched by the formation of aptamer/VEGF/antibody complex in the presence of aptamer. And then, an 18-nt elongated strand at the 3' end of aptamer, with the assist of invertase-functionalized auxiliary probe, triggered the hybridization chain reaction to generate invertase-concatamers. Vast invertase catalyzed sucrose to glucose, which is monitored through personal glucose meter. Finally, this portable sensing system can achieve the detection of limit of 1.2 pg/mL with good stability and selectivity. Meanwhile, VEGF in the serum would also be assayed with satisfied result. (C) 2017 Published by Elsevier B.V.