Facile and green synthesis of Au nanoparticles decorated Epigallocatechin-3-Gallate nanospheres with enhanced performance in stability, photothermal conversion and nanozymatic activity

In this study, epigallocatechin-3-gallate nanospheres (EGCG NSs) are employed as an innovative alternative to traditional reducing agents for the in-situ growth of AuNPs on the EGCG NS surface to produce the Au nanoparticles decorated EGCG nanospheres (EGCG NS@AuNPs). This eco-friendly approach avoids toxic chemicals and simplifies the synthesis process, enhancing biocompatibility and functional properties of the resulting EGCG NS@AuNPs nanocomposite. The nanocomposite exhibits remarkable stability, photothermal properties, and peroxidase-like enzymatic activity. Taking advantage of the enhanced photothermal properties, the application of EGCG NS@AuNPs in the antibacterial field was investigated, and the antibacterial activity was greatly improved against both Gram-negative and Gram-positive bacteria comparing to bare AuNPs or EGCG NS. Additionally, based on the excellent enzymatic activity, the sensing application of EGCG NS@AuNPs was explored by developing a colorimetric method for detecting ascorbic acid (AA). A remarkably low detection limit of 0.076 μM was achieved. This method has been successfully applied to measure the AA content in vitamin C tablets, demonstrating the practicality and accuracy of this approach. Therefore, the synthesis for EGCG NS@AuNPs is not only rapid, and cost-effective, but also eco-friendly and not harmful to biological systems, which is potential in biosensing, clinical diagnosis, and therapeutics. Future research could explore further applications of EGCG NS@AuNPs in biomedicine field, revealing even more of its remarkable potential.

Multifunctional Bi2S3-Au nanoclusters for fluorescence/infrared thermal imaging guided photothermal therapy

Nanotechnology has attracted extensive attention in the diagnosis and treatment of cancer. Therefore, the research aimed at developing new nanomaterials and exploring their applications in biomedicine has attracted more attention. In this study, Bi2S3-Au nanoclusters (Bi2S3-AuNCs) as fluorescence/infrared thermal imaging-guided photothermal therapy (PTT) was prepared for the first time. It was achieved in a facile and mild way by optimizing the amount of Bi3+ and Au3+ using bovine serum albumin (BSA) as reducer and stabilizer. The as-prepared Bi2S3-AuNCs with special morphology showed high stability, excellent biocompatibility and good photostability. Apart from these, it also can accumulate at tumor sites and exhibit considerable fluorescence/infrared thermal imaging-guided PTT. Bi2S3-AuNCs nanoparticles integrate imaging and therapeutic functions into an advanced application platform, which provides the possibility to build a novel nano-cancer diagnosis and treatment platform.

Bismuth-based two-dimensional nanomaterials for cancer diagnosis and treatment

The intrinsic high X-ray attenuation and insignificant biological toxicity of Bi-based nanomaterials make them a category of advanced materials in oncology. Bi-based two-dimensional nanomaterials have gained rapid development in cancer diagnosis and treatment owing to their adjustable bandgap structure, high specific surface area and strong NIR absorption. In addition to the single functional cancer diagnosis and treatment modalities, Bi-based two-dimensional nanomaterials have been certified for accomplishing multi-imaging guided multifunctional synergistic cancer therapies. In this review, we summarize the recent progress including controllable synthesis, defect engineering and surface modifications of Bi-based two-dimensional nanomaterials for cancer diagnosis and treatment in the past ten years. Their medical applications in cancer imaging and therapies are also presented. Finally, we discuss the potential challenges and future research priorities of Bi-based two-dimensional nanomaterials.

Inorganic Nanoflowers—Synthetic Strategies and Physicochemical Properties for Biomedical Applications: A Review

Nanoflowers, which are flower-shaped nanomaterials, have attracted significant attention from scientists due to their unique morphologies, facile synthetic methods, and physicochemical properties such as a high surface-to-volume ratio, enhanced charge transfer and carrier immobility, and an increased surface reaction efficiency. Nanoflowers can be synthesized using inorganic or organic materials, or a combination of both (called a hybrid), and are mainly used for biomedical applications. Thus far, researchers have focused on hybrid nanoflowers and only a few studies on inorganic nanoflowers have been reported. For the first time in the literature, we have consolidated all the reports on the biomedical applications of inorganic nanoflowers in this review. Herein, we review some important inorganic nanoflowers, which have applications in antibacterial treatment, wound healing, combinatorial cancer therapy, drug delivery, and biosensors to detect diseased conditions such as diabetes, amyloidosis, and hydrogen peroxide poisoning. In addition, we discuss the recent advances in their biomedical applications and preparation methods. Finally, we provide a perspective on the current trends and potential future directions in nanoflower research. The development of inorganic nanoflowers for biomedical applications has been limited to date. Therefore, a diverse range of nanoflowers comprising inorganic elements and materials with composite structures must be synthesized using ecofriendly synthetic strategies.

High-Performance Wearable Sensor Inspired by the Neuron Conduction Mechanism through Gold-Induced Sulfur Vacancies

Practical application of wearable gas-sensing devices has been greatly inhibited by the poorly sensitive and specific recognition of target gases. Rapid charge transfer caused by rich sensory neurons in the biological olfactory system has inspired the construction of a highly sensitive sensor network with abundant defect sites for adsorption. Herein, for the first time, we demonstrate an in situ formed neuron-mimic gas sensor in a single gas-sensing channel, which is derived from lattice deviation of S atoms in Bi₂S₃ nanosheets induced by gold quantum dots. Due to the favorable gas adsorption and charge transfer properties arising from S vacancies, the fabricated sensor exhibits a significantly enhanced response value of 5.6-5 ppm NO₂, ultrafast response/recovery performance (18 and 338 s), and excellent selectivity. Furthermore, real-time visual detection of target gases has been accomplished by integrating the flexible sensor into a wearable device.