Chitosan-initiated gold nanoparticles with enhanced fluorescence for unique Fe3+/PPi sensing and photothermal therapy

• Published in: Talanta (Oxford) 2024-05, Vol.271, p.125719-125719, Article 125719
• Main Authors: Wang, Ruihan, Xue, Liuyan, Dong, Xiaorui, Yan, Wenjun, Li, Yingqi
• Format: Article
• Language: English
• Subjects: biocompatibility; carboxylation; chitosan; detection limit; drug resistance; Fe3; fluorescence; Fluorescence enhancement; Gold nanoparticles; Highly selective detection; histidine; irradiation; ligands; nanogold; neoplasm cells; neoplasms; photoluminescence; Photothermal therapy; photothermotherapy; PPi; survival rate; toxicity
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2024.125719

The design of surface ligands is crucial for ligand-protected gold nanoparticles (AuNPs). Herein, following the principle of green synthesis, environmentally friendly gold nanoparticles (AuNPs@His@CC, AuHC) were fabricated based on dual ligands of histidine and carboxylated chitosan. AuHC showed the advantages of low toxicity, good photoluminescent stability and ideal biocompatibility. Compared with single histidine-coated gold nanoclusters (AuNCs@His, AuH), AuHC presented enhanced fluorescence attributed to the addition of chitosan. The blue-emitting AuHC has a unique response to Fe3+ with detection limits as low as 9.51 nM. Interestingly, the quenched fluorescence of AuHC–Fe3+ system could be restored through the introduction of PPi with a detection limit of 10.6 μM. So an “on-off-on” fluorescence sensing platform was achieved. Apart from good optical properties and sensing, the designed AuHC demonstrated outstanding photothermal conversion efficiency (27.8 %), which made it ideal material for thermal ablation of tumor. To be specific, after laser irradiation (660 nm, 0.78 W cm−2, 10 min) of AuHC, the survival rate of HeLa cells as a tumor cell model decreased to 12.7 %, indicating that AuHC has a significant tumor inhibition effect in vitro. Besides, AuHC also could be a befitting candidate for overcoming drug-resistant tumor cells such as MCF-7/ADR cells. Notably, AuHC can markedly ablate solid tumors in 4T1 tumor-bearing mice after laser irradiation (660 nm, 0.78 W cm−2, 10 min). Hence this work provides insight into the design of multifunctional AuNPs platform for simultaneously integrating the ion sensing and photothermal therapy of cancer. We design a facile, green and safe synthesis strategy to achieve gold nanoparticles (AuNPs@His@CC, AuHC). AuHC was fabricated with histidine and carboxylated chitosan as the double-coating reagents, which not only demonstrated a unique response to Fe3+ and PPi, but also significant photothermal treatment (PTT) of tumors. [Display omitted] •Gold nanoparticles (AuHC) were fabricated based on dual ligands of histidine and carboxylated chitosan by green synthesis.•AuHC has good biocompatibility and high photothermal conversion efficiency.•AuHC showed unique responses to Fe3+ and PPi with high selectivity and sensitivity.•AuHC demonstrated excellent PTT effect both in vivo and drug-resistant cells.