Aptamer based assay of plated-derived grow factor in unprocessed human plasma sample and MCF-7 breast cancer cell lysates using gold nanoparticle supported α-cyclodextrin.

Platelet-derived growth factor (PDGF), a protein biomarker, is directly involved in many cell transformation processes, such as tumor growth and progression. Elevation platelet-derived growth factor (PDGF-BB) concentration in plasma could indicate the accelerating growth of metastatic breast tumors and angiogenesis. The development of an apta-assay for detection of PDGF-BB in is presented in this work. A highly specific DNA-aptamer, selected to PDGF-BB was immobilized onto a gold nanoparticles supported α-cyclodextrin and electrochemical measurements were performed in a solution containing the phosphate buffer solution with physiological pH. Variety of shapes of gold nanostructures with different sizes from zero-dimensional nanoparticles to spherical structures were prepared by one-step template (α-cyclodextrin)-assistant green electrodeposition method. Fully electrochemical methodology was used to prepare a new transducer on a gold surface which provided a high surface area to immobilize a high amount of the aptamer. The surface morphology of electrode was characterized by high-resolution field emission scanning electron microscope (FE-SEM) and energy dispersive spectroscopy (EDX). The prepared aptasensors represented different electrochemical activities toward the redox processes of PDGF-BB attributing to the size and shape of the gold nanoparticles. The aptasensor was employed for the detection of PDGF using square wave voltammetry (SWV) and Cyclic voltammetry (CV) techniques. Under optimized condition the calibration curve for PDGF-BB was linear in 0.52-1.52nM with low limit of quantification of 0.52nM. Also, under the optimized experimental conditions, the proposed aptasensor of GNPs-cubic-α-CD-Apt-Au electrode exhibited excellent analytical performance for MCF-7 cells determination, ranging from 328 TO 593 cells mL-1 with low limit of quantification of 328 cells mL-1. As a result, the electrochemical aptasensor was able to detect cancer-related targets in unprocessed human plasma samples.