Dalian Minzu University

Recent advances in DNA-metal-organic framework (MOF)-based label-free biosensors have demonstrated significant potential for the early diagnosis of hepatocellular carcinoma through synergistic integration of materials science and molecular biology. These platforms offer notable advantages in sensitivity and cost-effectiveness compared to conventional diagnostic methods. However, critical challenges persist, particularly in achieving stable DNA immobilization on MOF surfaces while simultaneously guaranteeing high hybridization efficiency-a dual requirement essential for reliable biosensing performance. To address this fundamental limitation, we systematically studied DNA-MOF interfacial interactions, using DNA homopolymers as model systems. Mechanistic key insights were gained from a comparative analysis of the adsorption/desorption dynamics of alpha-fetoprotein (AFP) aptamers and their homologous oligonucleotide competitors onto two iron-based MOFs (MIL-53(Fe) and MIL-88B(Fe)). The target-induced binding of the AFP-aptamer complex was insufficient to fully dissociate the probes from the MOF surfaces, thereby limiting signal transduction. Competitive displacement assays revealed that poly C DNA exhibited superior affinity, enabling efficient aptamer replacement via surface competition. Based on this mechanism, a label-free cascaded amplification DNA biosensor was constructed, where poly C DNA-mediated aptamer release from MOF surface triggered rolling circle amplification (RCA) to generate repetitive DNA templates for in situ synthesis of silver nanoclusters (AgNCs) as fluorescence reporters. This DNA biosensor achieved sensitives AFP detection with a linear range of 10-100 ng mL^-1 and a detection limit of 2.3 ng mL^-1. This work expounds the underlying mechanisms governing MOF-DNA interfacial behavior and establishes a critical roadmap for developing highly sensitive and operationally label-free MOF-DNA-based biosensors.

Thermally enhanced upconversion luminescence demonstrates distinct advantages for optical thermometry in complex scenarios. In this work, NaYS₂:Tm³⁺ phosphors are synthesized via a solid-gas reaction method, followed by systematic investigation of the upconversion luminescence characteristic. The abundant energy level structure of Tm³⁺ enables its dual functionality as both sensitizer and activator, achieving self-sensitized upconversion luminescence. Under both 808 and 1208 nm excitation, significant thermal enhancement of emission is observed with elevating temperature, which can be attributed to activated phonon-assisted thermal population effect. The temperature-dependent luminescence of NaYS₂:Tm³⁺ is thoroughly analyzed by LIR technique, focusing on the thermally coupled energy levels of ¹G₄₍₁₎/¹G₄₍₂₎ and ³F₂/³F₃. Remarkably, the developed Tm³⁺ single-doped thermometer based on the luminescence thermal enhancement exhibits excellent temperature sensing performance under multi-wavelength excitation of 808 and 1208 nm, exhibiting promising potential for thermometry with wide temperature range and high sensitivity. These findings not only provide a viable strategy for achieving high performance thermometry but also deepen the understanding of thermal enhancement mechanisms in upconversion materials.

In recent years, plant-, animal-, and emerging-proteins have become prominent research topics in delivery systems. This review summarizes the properties of commonly used proteins, including zein, gliadin, soy protein, pea protein, whey protein, casein, ovalbumin, and gelatin, as well as emerging proteins such as algal protein, insect protein, and microbial protein. The assembly mechanisms and encapsulation techniques of proteins used as nanocarriers for the delivery of bioactive compounds are discussed, highlighting the central role of non-covalent interactions in the encapsulation process. Distinct from previous reviews, this paper not only emphasizes conventional protein-based encapsulation materials but also introduces new proteins and provides a comprehensive analysis of their assembly mechanisms and encapsulation strategies. Future research should prioritize the development of intelligent and sustainable protein-based materials, coupled with experimental validation and safety assessments, to address the diverse demands for high-performance encapsulation systems across the food, pharmaceutical, and other industries.