Effect of pH and Salt on Adsorption of Double-Stranded DNA on Graphene Oxide

Graphene oxide (GO) has a large surface-to-volume ratio and hydrophobic hexagonal rings that can interact with biomolecules. Single-stranded DNA adsorbs strongly to the surface of GO via hydrophobic interactions. GO has been used in optical biosensors and biomedical platforms for the detection of DNA, proteins, and small molecules. This study was designed to measure the adsorption of double-stranded DNA (dsDNA) onto GO according to DNA length, salt concentration, and pH of the reaction. Results showed that dsDNA molecules were adsorbed progressively as the pH changed from 6.0 to 4.0. At high pH, dsDNA adsorption was enhanced by the presence of MgCl2 rather than NaCl. Desorption of DNA from GO, with triton X-100 led to the rapid release of DNA from GO in the presence of MgCl2.

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GOLD NANOPARTICLES-BASED BIOSENSORS FOR BIOMEDICAL APPLICATION

Nano LIFE ◽

10.1142/s1793984412300087 ◽

2012 ◽

Vol 02 (04) ◽

pp. 1230008 ◽

Cited By ~ 4

Author(s):

JING ZHAO ◽

BING BO ◽

YONG-MEI YIN ◽

GEN-XI LI

Keyword(s):

Gold Nanoparticles ◽

Small Molecules ◽

Catalytic Properties ◽

Biomedical Application ◽

Photophysical Properties ◽

Volume Ratio ◽

Optical Biosensors ◽

Electrochemical Biosensors ◽

Adsorption Ability ◽

Strong Adsorption

Gold nanoparticles are the most extensively studied nanomaterials for biomedical application due to their unique properties, such as rapid and simple synthesis, large surface area, strong adsorption ability and facile conjugation to various biomolecules. The remarkable photophysical properties of gold nanoparticles have provided plenty of opportunities for the preparation of gold nanoparticles-based optical biosensors, while the excellent biocompatibility, conductivity, catalytic properties and large surface-to-volume ratio have facilitated the application of gold nanoparticles in the construction of electrochemical biosensors. In this review, we mainly detail the gold nanoparticles-based optical and electrochemical biosensors for biomedical application in the recent two years, which have exhibited greatly enhanced analytical performances in the detection of DNA, proteins and some important small molecules.

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Salt concentration, pH and pressure controlled separation of small molecules through lamellar graphene oxide membranes

Chemical Communications ◽

10.1039/c3cc41953c ◽

2013 ◽

Vol 49 (53) ◽

pp. 5963 ◽

Cited By ~ 252

Author(s):

Hubiao Huang ◽

Yiyin Mao ◽

Yulong Ying ◽

Yu Liu ◽

Luwei Sun ◽

...

Keyword(s):

Graphene Oxide ◽

Small Molecules ◽

Salt Concentration ◽

Oxide Membranes ◽

Pressure Controlled ◽

Graphene Oxide Membranes

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Loss of 111Indium as indicator of platelet injury

Blood ◽

10.1182/blood.v58.2.350.350 ◽

1981 ◽

Vol 58 (2) ◽

pp. 350-353 ◽

Cited By ~ 18

Author(s):

JH Joist ◽

RK Baker

Keyword(s):

Small Molecules ◽

Adenine Nucleotides ◽

Human Platelets ◽

Metabolic Energy ◽

Platelet Factor ◽

Platelet Protein ◽

Threshold Rate ◽

Immune Injury ◽

Triton X

Abstract We previously demonstrated that platelets can be labeled with 111Inoxine with high labeling efficiency and that 111In is not liberated from labeled platelets during the platelet release reaction or prolonged in vitro storage. In view of these findings, we examined the potential usefulness of loss of 111In from labeled platelets as an indicator or platelet damage by comparing the loss of 111In with that of 51Cr and LDH (in some experiments also with platelet factor 3 availability) under different conditions of platelet injury. When washed human platelets labeled with either 51Cr-chromate or 111In-oxine were exposed to increasing concentrations of detergents (Triton X-100, lysolecithin), threshold, rate, and extent of loss of 111In, 51Cr and, LDH were similar. In contrast, when labeled platelets were depleted of metabolic energy by incubation in glucose-free Tyrode albumin solution or glucose-depleted plasma in the presence of antimycin A and 2-deoxy-D- glucose, loss of 51Cr (and PF3a) occurred earlier and progressed at a faster rate than that of 111In or LDH. Similar results were obtained when platelets were exposed to increasing concentrations of PlA1 antibody, causing complement-mediated immune injury. The findings indicate that with certain agents that cause rapid platelet disruption (lysis), different platelet constituents are lost at similar rates. However, under conditions of more subtle or slowly progressive platelet injury, small molecules such as adenine nucleotides (51Cr) may escape earlier and at faster rates than larger molecules such as LDH or 111In- binding platelet protein. Thus, neither 111In loss nor LDH loss appear to be suitable indicators for sublytic or prelytic platelet injury.

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