Poly(Amic) Acid Copper Nanocubes as Biocide for Staphylococcus epidermidis

Area of Science:

• Materials Science
• Nanotechnology
• Electrochemistry

Background:

• Biodegradable polymers offer sustainable platforms for advanced materials.
• Controlling nanoparticle synthesis on polymer surfaces is crucial for tailored applications.
• Copper nanoparticles exhibit potent antimicrobial properties.

Purpose of the Study:

• To investigate the growth mechanism and pattern of copper nanocubes on polyamic acid films.
• To explore the role of applied potential in controlling copper nanocube synthesis.
• To evaluate the antibacterial efficacy of the synthesized copper nanocubes against resistant bacteria.

Main Methods:

• Polyamic acid (PAA) film fabrication via polycondensation.
• Electrochemical synthesis of copper nanocubes (CuNCs) using chronoamperometry.
• Characterization using SEM, AFM, TEM, XPS, and DFT calculations.
• Antibacterial activity assessment via time-kill assays against Staphylococcus epidermidis.

Main Results:

• Successfully synthesized uniform copper nanocubes (4.59 nm ± 0.20) on PAA films.
• Applied potential was identified as the key factor driving nucleation and growth.
• Density Functional Theory (DFT) revealed favorable copper ion complexation with PAA carboxyl groups.
• XPS confirmed the reduction of Cu²⁺ to Cu⁰ under applied potential.
• PAA-CuNCs demonstrated 100% inhibition of Staphylococcus epidermidis, outperforming conventional CuNPs.

Conclusions:

• Applied potential effectively controls the synthesis of copper nanocubes on PAA substrates.
• The synthesized PAA-CuNCs exhibit significant antibacterial activity against resistant microbes.
• Nanoparticle size and shape significantly influence antibacterial efficacy.
• This work presents a promising approach for developing novel antimicrobial materials.