Light Harvesting Modulation of Melanin-Like Polymers via Thiol-Michael “Click” Chemistry

Abstract

“Click” chemistry, featuring high selectivity, efficiency, and modularity, has been regarded as a powerful tool to construct and engineer macromolecular materials with complex and disordered structures. In this work, we reported our first effort to use the thiol-Michael “click” chemistry to tune the energy structure and light harvesting behavior of melanin-like polymers by “clicking” mercaptotetrazole (MT) building blocks into the complicated polydopamine (PDA) networks, successfully acquiring a series of melanin-like nanoparticles with boosted light absorption and photothermal effect. A comprehensive characterization by density functional theory (DFT) stimulation, spectral analysis, cyclic voltammetry, and transient absorption demonstrated the energy bandgap reduction and light harvesting enhancement of those MT-doped PDA samples. The resulting polymers also exhibited excellent photothermal effect, which could be applied in efficient electric energy generation through photothermoelectric conversion and solar desalination application. This study provided new opportunities to regulate the functions of a complex bioinspired macromolecule system through “click” chemistries.

Waste Tea-Derived Theabrownins for Solar-Driven Steam Generation

“…The mono-, bis-, and tris-coordination between catechol ligands in this unit and Fe­(III) were formed in the complex networks, potentially leading to the formation of numerous D–A pairs. The density functional theory (DFT) technique at the level of B3LYP/6-31g (d) was used to carry out the theoretical simulations of the potential molecular binding structures within TB@Fe­(III) complexes. , According to the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO) level results shown in Figure a, the simulated structures of TB@Fe­(III)- i ( i = 1–3) complexes in M2, M3, and M4 had significantly lower band gaps of 0.75, 0.45, and 0.84 eV, respectively, in comparison to the original structure unit shown in M1 (3.33 eV). Correspondingly, the electronic energy band gaps, as investigated by electrochemical cyclic voltammetry, showed the consistent results of that all TB@Fe­(III)- i ( i = 1–3) complexes exhibited lower energy levels compared with TB (Figure b,c).…”

Eumelanin-like Poly(levodopa) Nanoscavengers for Inflammation Disease Therapy

“…Eumelanin is a member of the natural melanin family, existing widely in the living organism that serves various biological functions, including UV protection, free radicals scavenging, metal chelation, and structural color. , Inspired by this, researchers have conducted extensive and in-depth research on the development and application of eumelanin-like polymers over the past decade. − Among them, polydopamine nanoparticles (PDA NPs) have become the most commonly used eumelanin-like nanomaterials due to their convenient preparation and properties similar to those of natural eumelanin. They play an important role in biomedical engineering, − energy, ,− and other fields. − However, the pursuit of more powerful performance has always been the focus of materials science so is the field of artificial eumelanin. ,− For example, in recent years, researchers have worked hard to improve the antioxidant properties of PDA NPs to better meet the existing demands.…”

Quaternary Ammonium Assisted Synthesis of Melanin-like Poly(l-DOPA) Nanoparticles with a Boosted Photothermal Effect

“…Inspired by nature, polydopamine nanoparticle (PDA NP)-based melanin-like materials have been popularly shining in biomedical, − energy, − and other fields. ,,− It is worth noting that poly­(levodopa) nanoparticles (P­( l -DOPA) NPs), as another typical kind of melanin mimetic, have also emerged in recent years, showing superior performance and great potential in many areas. − Several methods have been developed for the preparation of P­( l -DOPA) NPs, such as employing ammonia, strong oxidants, and enzymes. ,,,, However, these strategies are plagued by problems including poor controllability, high cost, or damaged functional groups. Very recently, metal ions were found to be efficient in achieving the controlled synthesis of P­( l -DOPA) NPs .…”