Sequential super-assembled nanomotor adsorbents for NIR light-Powered blood lead removal

Abstract

Hemoperfusion is a common treatment for lead poisoning, where hemoperfusion adsorbents are used to remove lead ions from blood. However, traditional hemoperfusion adsorbents often suffer from limited efficiency and poor biocompatibility, reducing their effectiveness for human use. To address these limitations, we developed a novel photothermal nanomotor adsorbent through a controllable sequential super-assembly strategy. Gold nanoparticles (Au NPs) were incorporated into the nanochannels of halloysite nanotubes (HNTs), followed by modification of the outer HNT surface with polydopamine (PDA) and 2,3-dimercaptosuccinic acid (DMSA), forming Au@HNTs@PDA-DMSA. This nanomotor adsorbent leverages the photothermal properties of Au NPs to achieve self-propulsion via thermophoresis under near-infrared (NIR) light irradiation. The performance of this nanomotor was evaluated for Pb(II) removal in both aqueous solutions and human blood samples, reaching adsorption equilibrium within 20 min and a maximum capacity of 45.980 mg/g. The adsorption kinetics followed a pseudo-second-order model with a high fitting coefficient (R² = 0.999), and the Langmuir model fit better than the Freundlich model, indicating monolayer adsorption. Notably, when driven by 808 nm NIR light at 1.0 W cm⁻², the Au@HNTs@PDA-DMSA nanomotors showed a significantly enhanced adsorption capacity of 151.769 mg/g, improving blood lead removal efficiency by 1.80 times compared to non-irradiated conditions. Furthermore, the addition of sulfhydryl and carboxyl groups from DMSA provided more active sites, leading to a 9.76-fold increase in lead removal compared to passive adsorbents using HNTs. In vitro tests confirmed the excellent biocompatibility and biosafety of the nanomotor adsorbent, achieving a blood lead removal rate of 91.25 %. This advancement overcomes the limitations of traditional lead adsorbents, offering a promising solution for more effective lead detoxification in clinical and environmental settings.