A Highly Efficient Electroaptasensor for VEGF Detection by Employing Peroxidase-Like Activity Mesoporous Pt Nanospheres

Abstract

Abstract.A new type of peroxidase-like activity mesoporous Pt nanospheres (MPNs) were synthesized through a slow reduction reaction, and applied in electroaptasensor for the detection of the VEGF (Figure 1). MPNs with excellent peroxidase mimicking properties, large specific surface areas, good biocompatibility, electrocatalytic activity and structural thermostability. Thus, thiol-functionalized aptamer were modified on MPNs as an electrocatalytic label by the electrocatalyzed reduction of H 2 O 2 . Firstly, primary VEGF aptamers (Ap1) were immobilized on the surface of Au electrode. The target VEGF was captured by the immobilized Ap1. Then, the secondary VEGF aptamers (Ap2) were modified on MPNs that possess strong peroxidase-like activity, which acted as catalytic labels for the electrochemical detection of VEGF. The electrochemical signal was significantly increased as the strong catalytic activity of MPNs to reduce H 2 O 2 . Otherwise, the MPNs with excellent electrocatalytic activity could further enhancing sensitivity of the assay, as it increased the electron transfer at the electrode surface. This strategy provided a universal platform for sensitive and specific detection of a wide spectrum of analytes, by altering the sequence of aptamers. Moreover, the prepared aptasensor exhibited promising properties, which would become a simple and powerful tool for bioanalysis and clinic diagnostic application.