Highly sensitive detection for proteins using graphene oxide-aptamer based sensors

Abstract

In recent years, the detection of proteins by using bare graphene oxide (GO) to quench the fluorescence of fluorescein-labeled aptamers has been reported. However, the proteins can be adsorbed on the surface of bare GO to prevent the sensitivity from further being improved. In order to solve this problem, polyethylene glycol (PEG)-protected GO was used to prevent the proteins using thrombin as an example from nonspecific binding. The detection limit was improved compared to bare GO under the optimized ratio of GO to PEG concentration. The results show that our method is a promising technique for the detection of proteins.

Highly sensitive protein detection via covalently linked aptamer to MoS₂ and exonuclease-assisted amplification strategy

“…It was lower than those obtained from other reported assays (Table 1), such as surface plasmon resonance (50 nM), 22 graphene oxide-aptamer sensor (4.8 pM), 18 paper analytical device (16 nM), 23 and quartz crystal microbalance (0.1nM), 24 graphene nanocomposites (0.01 nM), 25 and electrochemical sandwich assay (1.5 pM). 26 It was also lower than that obtained from similar mechanisms using other sensors, such as graphene oxide sensor (0.9 pM), 16 strip biosensor (4.9 pM), 27 and AuNP sensor (0.31 nM).…”

“…Tween 80 was also reported as a blocking agent that prevents the absorbability of nonspecific binding materials by interacting with the AuNPs@MoS 2 nanocomposites through its hydrocarbon. [18][19][20] In this study, it improved the sensitivity by preventing nonspecific adsorption of thrombin on the surface of MoS 2 . Figure S7A illustrates the fluorescence emission spectra of MoS 2 -aptamer with varying concentrations of thrombin.…”

“…DNA/AuNPs conjugates can be rapidly formed in 0.01 M PBS (0.1 M NaCl, 10 mM phosphate, pH 7.4) at 50°C followed by a ligand exchange between Tween 80 and thiol-DNA. 18 The aptamer modified with thiol was immobilized on the surface of AuNPs in 2.5 h using 10% (v/v) Tween 80 compared to more than 12 h without using Tween 80. Tween 80 was also reported as a blocking agent that prevents the absorbability of nonspecific binding materials by interacting with the AuNPs@MoS 2 nanocomposites through its hydrocarbon.…”

“…RecJf Exo degraded the aptamer in the aptamer-thrombin complex in the direction 5′→3′, causing thrombin to be released into the solution for target recycling. 16 Tween 80, a nonionic surfactant that strongly interacts with MoS 2 through its hydrocarbon, 18,19 was used to prevent the protein from nonspecific binding to improve the detection limit.…”

Ti-GO-Ag nanocomposite: the effect of content level on the antimicrobial activity and cytotoxicity

“…16,17 The features of GO could enhance its interactions with proteins through covalent, hydrogen bonding and electrostatic nature. [18][19][20] GO could promote the differentiation of stem cells, cell growth, expansion and proliferation. Additionally, it is often used as carrier to minimize the surface energy in the preparation process.…”