Dopamine: Acid-base properties and membrane penetration capacity

Calixarenes: Generalities and Their Role in Improving the Solubility, Biocompatibility, Stability, Bioavailability, Detection, and Transport of Biomolecules

“…Among the many substances that can be recognized by calixarenes is dopamine (Figure 7), which is a neurotransmitter of vital importance for the normal function of the central nervous system. The lack of this substance is one of the causes of Parkinson’s disease, an illness that affects more than 10 million people worldwide [60]. In addition, alterations in the normal levels of dopamine are associated with attention-deficit hyperactivity disorder, which affects between 2 and 7% of children, adolescents, and adults in the world [61].…”

Synthesis of Ultrasmall Fe3O4 Nanoparticles as T1–T2 Dual-Modal Magnetic Resonance Imaging Contrast Agents in Rabbit Hepatic Tumors

“…This phenomenon is probably due to the fact that steric stabilization of dopamine coated on the nanoparticles is very weak, while in an acid solution, strong charge repulsion of the surface dopamine layer prevented aggregation of these nanoparticles. 38 To improve the stability of DPA@Fe 3 O 4 , bull serum albumin (BSA), which is a cheap and biocompatible biomacromolecule, is chemically coupled on the surface of DPA@Fe 3 O 4 to prepare the BSA@Fe 3 O 4 nanoparticles. BSA not only improves steric stabilization but also provides a negative surface charge in the solution.…”

“…However, with an increase of the pH, especially under neutral conditions, the nanoparticles were unstable and became aggregates (Figure S3b). This phenomenon is probably due to the fact that steric stabilization of dopamine coated on the nanoparticles is very weak, while in an acid solution, strong charge repulsion of the surface dopamine layer prevented aggregation of these nanoparticles . To improve the stability of DPA@Fe 3 O 4 , bull serum albumin (BSA), which is a cheap and biocompatible biomacromolecule, is chemically coupled on the surface of DPA@Fe 3 O 4 to prepare the BSA@Fe 3 O 4 nanoparticles.…”

Modifier-free gold nanoparticle colorimetric sensing for detecting sulfanilamide in the presence of dopamine

“…17 This positive charge is strongly attracted by the negatively charged citrate on the surface of the AuNPs due to electrostatic interactions. 49 Hydrogen bonding, specifically, the intermolecular hydrogen bonding between two adjacent OH groups in DA, plays an important role in the process of nanoparticle aggregation to give a blue color. 50 Likewise, photographs and UV-Vis studies were employed to monitor the interactions of DA with citrate-coated AuNPs over a range of pH values from 3.0 to 11.0.…”