Combination of aptamer with gold nanoparticles for electrochemical signal amplification: Application to sensitive detection of platelet-derived growth factor

In this paper, we report a novel electrochemical detection approach for platelet-derived growth factor (PDGF) via “sandwich” structure and gold nanoparticles (Au-NPs) mediated amplification technique. The “sandwich” structure is fabricated based on the fact that PDGF has two aptamer-binding sites, which makes it possible for one PDGF molecule to connect with two aptamers simultaneously. It is found that this electrochemical system with “sandwich” structure and Au-NPs can significantly amplify the signal of electrochemical probe [Ru(NH3)5Cl]2+ for PDGF detection, and thus increase the detection sensitivity significantly. As a result, this PDGF detection approach obtains an extraordinarily low detection limit of 1 × 10−14 M for purified samples, 1 × 10−12 M for contaminated-ridden samples or undiluted blood serum. This detection approach can also exhibit good stability and excellent specificity.