Ruey-an Doong
National Chiao Tung University, Taiwan
Title: Amperometric biosensors for cancer maker detection using novel dumbbell-like gold-magnetite nanocomposites
Biography
Biography: Ruey-an Doong
Abstract
An ultrasensitive amperometric immunosensor for the detection of cancer biomarker, ï¡-fetoprotein (AFP), was fabricated using Au/chitosan modified glassy carbon electrode (GCE) and antibody-functionalized dumbbell-like Au-Fe3O4 heterostructures as Biosensing platform and immuno-labels, respectively. To fabricate the labels, nano-Au NPs were first epitaxially grown onto Fe3O4 surface to form the dumbbell-like Au-Fe3O4 followed by conjugation of secondary antibody onto Au surface (Au-Fe3O4-Ab2). Results showed that the GCE modified with chitosan produced high electrochemical response by conjugation of more Au-Ab1 and the dumbbell-like Au-Fe3O4 served as a dual-probe to immobilize Ab2 onto Au as well as to reduce H2O2 by Fe3O4, resulting in the enhancement of signal amplification. The prepared Au-Fe3O4/Ab2/AFP/Ab1/Au/chitosan/GCE immunosensors exhibited a good analytical performance in the presence of 10 mM H2O2 with wide dynamic range of 4 orders of magnitude (0.01–40 ng mL-1) and low detection limit of 2.3 pg mL-1. In addition, the dumbbell-like Pt-Fe3O4 nanoparticles have been used to fabricate the amperometric biosensors for detection of dopamine. The Pt-Fe3O4-based electrode is linearly dependence on dopamine concentration in the range of 10-850 ïM with the detection limits of 0.13-7.22 ïM. Results obtained in this study clearly demonstrate that the dumbbell-like metal-magnetite biosensor is a promising biosensing platform for highly sensitive detection of tumor makers and neurotransmitters.
