Three-dimensional Graphene Network Decorated with Bimetallic Cerium/Copper Oxide Nanoparticles for Non-enzymatic Diagnosis of Phenylketonuria

A "Turn-on" fluorescence sensing strategy based on DNA-templated silver nanoclusters for the detection of antibiotic resistance genes

BACKGROUND

Antibiotic resistance genes (ARGs) are emerging environmental contaminants that pose serious threats to human health and ecological security due to their rapid migration and transformation in the environment. Thus, developing a sensitive and rapid method to detect ARGs is significant.

RESULTS

In this study, the neighborhood-dependent fluorescent sensor was established with DNA templated silver nanoclusters (AgNCs) and multi-branched linear structure to detect the typical macrolide resistance gene ermB. A DNA fluorescent probe with a specific recognition fragment for AgNCs and a tuning enhancement sequence were designed. The probe and the target resistance genes were complementary hybridized to form a linear multi-branch DNA structure of bright yellow silver nanocluster beacon that realized fluorescence signal amplification and transduction.

SIGNIFICANCE

This method has the advantages of being enzyme-free, label-free and amplification-free for being applied to the rapid detection of specific ARGs and successfully detected macrolide resistance gene ermB with the LOD as low as 0.37 nM in environmental samples with complex composition.

Recent Advances in Biosensors Based on Hybridization Chain Reaction and Silver Nanoclusters

Hybridization chain reaction (HCR) and DNA-templated silver nanoclusters (AgNCs) have emerged as powerful tools in biosensing. HCR enables cascade amplification through programmable DNA interactions, while DNA-AgNCs serve as transducing units with unique fluorogenic and electrochemical properties. Integrating these components into a hybrid sensor could significantly enhance sensing capabilities across various fields. Nonetheless, limited studies and the lack of systematic guidelines for HCR-AgNCs systems have hindered research progress, despite their potential. This review aims to address this gap by providing a comprehensive overview of HCR-AgNCs biosensors, facilitating further innovation in this field. The working principles, performance factors, and complementary features are discussed. Thereafter, reported HCR-AgNCs studies are assessed, emphasizing their distinct sensing mechanisms (e.g., fluorogenic, electrochemical), applications across various fields, and challenges in adopting the hybrid sensors. Drawing from the experience developing multiple HCR-AgNCs sensors, insights and guidelines for designing and developing HCR-AgNCs systems are provided for future researchers. Finally, prospective directions in HCR-AgNCs research, including multiplex assays and integration with emerging technologies, are explored to guide future advancements. The synergistic combination of HCR and AgNCs as a hybrid biosensor holds promise for addressing pressing challenges in healthcare, environmental monitoring, and beyond, paving the way for next-generation biosensing technologies.

Aggregation-induced emission(AIE)for next-generation biosensing and imaging: A review

Luminescence technology is a powerful analytical tool for biomedical research as well as for marker detection. Luminescent materials with aggregation-induced emission (AIE) properties have attracted extensive research interest, and their unique luminescence characteristics, biocompatibility, and sensitivity make them useful for the development of fluorescence-turn-on biosensors with superior sensitivity. While numerous reviews have focused on the design of AIEgens, comprehensive summaries on the strategies for biosensor preparation and application fields remain limited. In this review, we provide a concise introduction to the discovery and mechanism of the AIE phenomenon and summarize the working principles of classic AIE molecules. We discuss luminescence tuning strategies and functionalization methods for AIEgens, along with the design and preparation of AIE-based biosensors. Typical applications of AIE in biosensing and imaging are outlined, and we analyze the current limitations and future research directions of AIE technology in these fields. We hope this review will serve as a valuable reference for researchers in this rapidly developing field. The insights provided may facilitate the rational design of next-generation biosensors based on AIE technology, exhibiting promising avenues of biomedical applications and vast potential for growth.

Aggregation-Induced Emission Properties of Atypical Aliphatic-Chain-Linked Siloxanes-Containing Phosphonate Esters

Phosphonate compounds have been proposed as atypical chromophores, but their luminescence properties, especially in combination with flexible aliphatic chains, remain underexplored. In this study, we have synthesized a series of novel siloxane-containing phosphonate esters as organofluorophores through a catalyst-free, one-pot Kabachnik-Fields (K-F) reaction. This reaction involved acetone, cyclohexanone, or cyclopentanone, with siloxanes containing aliphatic amines and phosphonate diesters as reactants. The resulting compounds exhibit blue fluorescence. Fluorescence tests confirmed that all synthesized materials display aggregation-induced emission (AIE) phenomena, with some also exhibiting upconversion. Notably, the luminescence intensity can be modulated by altering the steric hindrance near the phosphonate ester group. Mechanistic studies indicate that the strong blue photoluminescence observed in the aggregated state results from restricted intramolecular motion (RIM) and spatial electronic delocalization. These findings demonstrate that even simple phosphonates, when combined with flexible aliphatic chains, can exhibit significant AIE luminescence properties.

A fluorescent sensor array based on antibiotic-stabilized metal nanoclusters for the multiplex detection of bacteria

To address the need for facile, rapid detection of pathogens in water supplies, a fluorescent sensing array platform based on antibiotic-stabilized metal nanoclusters was developed for the multiplex detection of pathogens. Using five common antibiotics, eight different nanoclusters (NCs) were synthesized including ampicillin stabilized copper NCs, cefepime stabilized gold and copper NCs, kanamycin stabilized gold and copper NCs, lysozyme stabilized gold NCs, and vancomycin stabilized gold/silver and copper NCs. Based on the different interaction of each NC with the bacteria strains, unique patterns were generated. Various machine learning algorithms were employed for pattern discernment, among which the artificial neural networks proved to have the highest performance, with an accuracy of 100%. The developed prediction model performed well on an independent test dataset and on real samples gathered from drinking water, tap water and the Anzali Lagoon water, with prediction accuracy of 96.88% and 95.14%, respectively. This work demonstrates how generic antibiotics can be implemented for NC synthesis and used as recognition elements for pathogen detection. Furthermore, it displays how merging machine learning techniques can elevate sensitivity of analytical devices.

A dual-targeting nanobiosensor for Gender Determination applying Signal Amplification Methods and integrating Fluorometric Gold and Silver Nanoclusters

A dual-targeting nanobiosensor has been developed for the simultaneous detection of AMELX and AMELY genes based on the different fluorescence signals emitted from gold and silver nanoclusters, AuNCs and AgNCs respectively. In our design, both catalytic hairpin assembly (CHA) and hybridization chain reaction (HCR) have been used as isothermal, enzyme-free and simple methods for signal's amplification. The working principle is based on the initiation of a cascade of CHA-HCR reactions when AMELX is present, in which AuNCs, synthesized on the third hairpin, are aggregated on the surface of the dsDNA product, performing the phenomenon of aggregation induced emission (AIE) and enhancing their fluorescence signal. On the other hand, the presence of the second target, AMELY, is responsible for the enhancement of the fluorescence signal corresponding to AgNCs by the same phenomenon, via hybridizing to the free end of the dsDNA formed and at the same time to the probe of silver nanoclusters fixing it closer to the surface of the dsDNA product. Such a unique design has the merits of being simple, inexpensive, specific and stable and presents rapid results. The detection limits of this assay for AMELX and AMELY are as low as 3.16 fM and 23.6 fM respectively. Moreover, this platform showed great performance in real samples. The design has great promise for the application of dual-targeting nanobiosensors to other biomarkers.