# Exploring Dopamine Neurotransmitter and Silver Nanocluster (Agn; n = 4–20) Interactions: DFT Insights for Biomedical Applications

## TL;DR

This study uses computational methods to explore how dopamine interacts with silver nanoclusters, revealing strong binding and stability that could be useful in biosensing.

## Contribution

The study provides new insights into dopamine-silver nanocluster interactions using DFT and QTAIM analysis, highlighting their stability and potential biomedical applications.

## Key findings

- Silver nanoclusters bind strongly to dopamine's amine group with adsorption energies between −20 and −30 kcal/mol.
- QTAIM analysis confirms ionic Ag–N bonds with low electron densities and positive Laplacians.
- Selected systems (DOP@Ag5 and DOP@Ag10) show thermal and structural stability at 320 K in simulations.

## Abstract

This study investigates the interactions between silver
nanoclusters
(Agn; n = 4–20) and the dopamine
neurotransmitter using density functional theory calculations. Our
results demonstrate significant binding of silver nanoclusters to
the amine group of the ethylamine side chain of dopamine. The adsorption
energies range from −20 to −30 kcal/mol, suggesting
favorable interactions. The results reveal strong binding specifically,
supported by molecular electrostatic potential, quantum theory of
atoms in molecules (QTAIM), and reduced density gradient analyses.
The influence of water as a solvent on the interactions was also evaluated
through the integral equation formalism-polarizable continuum model.
The presence of water as a solvent slightly affects the stability
and electronic features, notably increasing the dipole moments and
solubility in polar environments. QTAIM analysis confirms the existence
of dative Ag–N bonds with ionic character, characterized by
low electron densities and positive Laplacians. Ab initio molecular
dynamics simulations of select systems (DOP@Ag5 and DOP@Ag10) demonstrate their thermal and structural stability at 320
K, indicating their robustness under physiological conditions. Overall,
this work offers insights into the adsorption mechanisms of dopamine
on silver nanoclusters with potential implications for advancements
in biosensing applications.