Paper Info
Title
Combination Of Aptamer Amplifier And Antigen-Binding Fragment Probe As A Novel Strategy To Improve Detection Limit Of Silicon Nanowire Field-Effect Transistor Immunosensors
Abstract
Detecting proteins at low concentrations in high-ionic-strength conditions by silicon nanowire field-effect transistors (SiNWFETs) is severely hindered due to the weakened signal, primarily caused by screening effects. In this study, aptamer as a signal amplifier, which has already been reported by our group, is integrated into SiNWFET immunosensors employing antigen-binding fragments (Fab) as the receptors to improve its detection limit for the first time. The Fab-SiNWFET immunosensors were developed by immobilizing Fab onto Si surfaces modified with either 3-aminopropyltriethoxysilane (APTES) and glutaraldehyde (GA) (Fab/APTES-SiNWFETs), or mixed self-assembled monolayers (mSAMs) of polyethylene glycol (PEG) and GA (Fab/PEG-SiNWFETs), to detect the rabbit IgG at different concentrations in a high-ionic-strength environment (150 mM Bis-Tris Propane) followed by incubation with R18, an aptamer which can specifically target rabbit IgG, for signal enhancement. Empirical results revealed that the signal produced by the sensors with Fab probes was greatly enhanced compared to the ones with whole antibody (Wab) after detecting similar concentrations of rabbit IgG. The Fab/PEG-SiNWFET immunosensors exhibited an especially improved limit of detection to determine the IgG level down to 1 pg/mL, which has not been achieved by the Wab/PEG-SiNWFET immunosensors.
Year
DOI
Venue
2021
10.3390/s21020650
SENSORS
Keywords
DocType
Volume
silicon nanowire field-effect transistor biosensor, aptamer, Fab, ELISA, mixed self-assembled monolayer, signal enhancement
Journal
21
Issue
ISSN
Citations 
2
1424-8220
0
PageRank 
References 
Authors
0.34
0
6
Name
Order
Citations
PageRank
Cao-An Vu100.34
Pin-Hsien Pan200.34
Yuh-Shyong Yang300.34
Hardy Wai-Hong Chan400.34
Yoichi Kumada500.34
Wen-Yih Chen600.34