Background: The coalition of DNA nanotechnology with diversiform inorganic nanoparticles offers powerful tools for the design and construction of stimuli-responsive drug delivery systems with spatiotemporal controllability, but it remains challenging to achieve high-density oligonucleotides modification close to inorganic nanocores for their sensitive responsivity to optical or thermal signals. Results: Inspired by Actinia with retractable tentacles, here we design an artificial nano-Actinia consisted of collapsible DNA architectures attached on gold nanoparticle (AuNP) for efficient drug delivery and enhanced photothermal therapy. The collapsible spheroidal architectures are formed by the hybridization of long DNA strand produced in situ through rolling circle amplification with bundling DNA strands, and contain numerous double-helical segments for the intercalative binding of quercetin as the anti-cancer drug. Under 800-nm light irradiation, the photothermal conversion of AuNPs induces intensive localized heating, which unwinds the double helixes and leads to the disassembly of DNA nanospheres on the surface of AuNPs. The consequently released quercetin can inhibit the expression of heat shock protein 27 and decrease the thermal resistance of tumor cells, thus enhancing photothermal therapy efficacy. Conclusions: By combining the deformable DNA nanostructures with gold nanocores, this Actinia-mimetic nanocarrier presents a promising tool for the development of DNA-AuNPs complex and opens a new horizon for the stimuli-responsive drug delivery. Graphical

Monitoring of immune factors, including interferon-gamma (IFN-γ), holds great importance for understanding immune responses and disease diagnosis. Wearable sensors enable continuous and non-invasive detection of immune markers in sweat, drawing significant attention to their potential in real-time health monitoring and personalized medicine. Among these, electrochemical sensors are particularly advantageous, due to their excellent signal responsiveness, cost-effectiveness, miniaturization, and broad applicability, making them ideal for constructing wearable sweat sensors. In this study, we present a flexible and sensitive wearable platform for the detection of IFN-γ, utilizing a DNA hydrogel with favorable loading performance and sample collection capability, and the application of mobile software achieves immediate data analysis and processing. This platform integrates three-dimensional DNA hydrogel functionalized with IFN-γ-specific aptamers for precise target recognition and efficient sweat collection. Signal amplification is achieved through target-triggered catalytic hairpin assembly (CHA), with DNA hairpins remarkably enhancing sensitivity. Ferrocene-labeled reporting strands immobilized on a screen-printed carbon electrode are displayed via CHA-mediated strand displacement, leading to a measurable reduction in electrical signals. These changes are transmitted to a custom-developed mobile application via a portable electrochemical workstation for real-time data analysis and recording. This wearable sensor platform combines the specificity of DNA aptamers, advanced signal amplification, and the convenience of mobile data processing. It offers a high-sensitivity approach to detecting low-abundance targets in sweat, paving the way for new applications in point-of-care diagnostics and wearable health monitoring.