Search Results (9)

The rapid and accurate detection of pathogenic bacteria and viruses is critical for infectious disease control and public health protection. While conventional methods (e.g., culture, microscopy, serology, and PCR) are widely used, they are often limited by lengthy processing times, high costs, and specialized equipment requirements. In recent years, metal nanocluster (MNC)-based biosensors have emerged as powerful diagnostic platforms due to their unique optical, catalytic, and electrochemical properties. This systematic review comprehensively surveys advancements in MNC-based biosensors for bacterial and viral pathogen detection, focusing on optical (colorimetric and fluorescence) and electrochemical platforms. Three key aspects are emphasized: (1) detection mechanisms, (2) nanocluster types and properties, and (3) applications in clinical diagnostics, environmental monitoring, and food safety. The literature demonstrates that MNC-based biosensors provide high sensitivity, specificity, portability, and cost-efficiency. Moreover, the integration of nanotechnology with biosensing platforms enables real-time and point-of-care diagnostics. This review also discusses the limitations and future directions of the technology, emphasizing the need for enhanced stability, multiplex detection capability, and clinical validation. The findings offer valuable insights for developing next-generation biosensors with improved functionality and broader applicability in microbial diagnostics. Full article

The early detection of genetic diseases is a critical need in modern medicine, underscoring the importance of developing deoxyribonucleic acid (DNA) biosensors. In recent years, metal nanoclusters (MNCs) have demonstrated significant potential as biosensors for DNA detection due to their ultra-small size, excellent photostability, bright photoluminescence, low toxicity and other outstanding properties. This review firstly discusses the characteristics of MNCs, which are effective in the early diagnosis of DNA diseases. Subsequently, different synthesis methods of MNCs are introduced. In the following section, DNA sensors based on different types of MNCs and their respective detection mechanisms are discussed in detail. Finally, the opportunities and challenges faced by DNA sensors based on MNCs are analyzed. Full article

Metal ion contamination has serious impacts on environmental and biological health, so it is crucial to effectively monitor the levels of these metal ions. With the continuous progression of optoelectronic nanotechnology and biometrics, the emerging electrochemiluminescence (ECL) biosensing technology has not only proven its simplicity, but also showcased its utility and remarkable sensitivity in engineered monitoring of residual heavy metal contaminants. This comprehensive review begins by introducing the composition, advantages, and detection principles of ECL biosensors, and delving into the engineered aspects. Furthermore, it explores two signal amplification methods: biometric element-based strategies (e.g., HCR, RCA, EDC, and CRISPR/Cas) and nanomaterial (NM)-based amplification, including quantum dots, metal nanoclusters, carbon-based nanomaterials, and porous nanomaterials. Ultimately, this review envisions future research trends and engineered technological enhancements of ECL biosensors to meet the surging demand for metal ion monitoring. Full article

Enzymes play a critical role in most complex biochemical processes. Some of them can be regarded as biomarkers for disease diagnosis. Taking advantage of aggregation-induced emission (AIE)-based biosensors, a series of fluorogens with AIE characteristics (AIEgens) have been designed and synthesized for the detection and imaging of enzymes. In this work, we summarized the advances in AIEgens-based probes and sensing platforms for the fluorescent detection of enzymes, including proteases, phosphatases, glycosidases, cholinesterases, telomerase and others. The AIEgens involve organic dyes and metal nanoclusters. This work provides valuable references for the design of novel AIE-based sensing platforms. Full article

A bioluminescence-based assay for ATP can measure cell viability. Higher ATP concentration indicates a higher number of living cells. Thus, it is necessary to design an ATP sensor that is low-cost and easy to use. Gold nanoparticles provide excellent biocompatibility for enzyme immobilization. We investigated the effect of luciferase proximity with citrate-coated gold, silver, and gold–silver core–shell nanoparticles, gold nanorods, and BSA–Au nanoclusters. The effect of metal nanoparticles on the activity of luciferases was recorded by the luminescence assay, which was 3–5 times higher than free enzyme. The results showed that the signal stability in presence of nanoparticles improved and was reliable up to 6 h for analytes measurements. It has been suggested that energy is mutually transferred from luciferase bioluminescence spectra to metal nanoparticle surface plasmons. In addition, we herein report the 27-base DNA aptamer for adenosine-5′-triphosphate (ATP) as a suitable probe for the ATP biosensor based on firefly luciferase activity and AuNPs. Due to ATP application in the firefly luciferase reaction, the increase in luciferase activity and improved detection limits may indicate more stability or accessibility of ATP in the presence of nanoparticles. The bioluminescence intensity increased with the ATP concentration up to 600 µM with a detection limit of 5 µM for ATP. Full article

The findings from the synthetic mechanism of metal nanoclusters yield the etching chemistry based on coinage metal nanoclusters. The utilization of such chemistry as a tool that can alter the optical properties of metal nanoclusters has inspired the development of a series of emerging luminescent biosensors. Compared with other sensors, the luminescent biosensors have the advantages of being more sensitive, saving time and saving cost. We reviewed topics on the luminescent sensors based on the etching of emissive coinage metal nanoclusters. The molecules possessing varied etching ability towards metal nanoclusters were categorized with discussions of corresponding etching mechanisms. The understanding of etching mechanisms favored the discussions of how to use etching methods to detecting biochemical molecules. The emerging luminescent biosensors via etching chemistry also provided challenges and new opportunities for analytical chemistry and sensors. Full article

Atomically precise silver nanoclusters (AgNCs) are small nanostructures consisting of only a few atoms of silver. The combination of AgNCs with cytosine-rich single-stranded oligonucleotides results in DNA-templated silver nanoclusters (DNA-AgNCs). DNA-AgNCs are highly luminescent and can be engineered with reproducible and unique fluorescent properties. Furthermore, using nucleic acids as templates for the synthesis of AgNCs provides additional practical benefits by expanding optical activity beyond the visible spectral range and creating the possibility for color tunability. In this study, we explore DNA oligonucleotides designed to fold into hairpin-loop (HL) structures which modulate optical properties of AgNCs based on the size of the loop containing different number of cytosines (HL-C_N). Depending on the size of the loop, AgNCs can be manufactured to have either single or multiple emissive states. Such hairpin-loop structures provide an additional stability for AgNCs and further control over the base composition of the loop, allowing for the rational design of AgNCs’ optical properties. We demonstrate the potential of AgNCs in detecting Hg²⁺ by utilizing the HL-C₁₃ design and its variants HL-T₂C₁₁, HL-T₄C₉, and HL-T₆C₇. The replacement of cytosines with thymines in the loop was intended to serve as an additional sink for mercury ions extending the detectable range of Hg²⁺. While AgNC@HL-T₀C₁₃ exhibits an interpretable quenching curve, AgNC@HL-T₆C₇ provides the largest detectable range of Hg²⁺. The results presented herein suggest that it is possible to use a rational design of DNA-AgNCs based on the composition of loop sequence in HL structures for creating biosensors to detect heavy metals, particularly Hg²⁺. Full article

Nanozymes are a class of artificial enzymes that have dimensions in the nanometer range and can be composed of simple metal and metal oxide nanoparticles, metal nanoclusters, dots (both quantum and carbon), nanotubes, nanowires, or multiple metal-organic frameworks (MOFs). They exhibit excellent catalytic activities with low cost, high operational robustness, and a stable shelf-life. More importantly, they are amenable to modifications that can change their surface structures and increase the range of their applications. There are three main classes of nanozymes including the peroxidase-like, the oxidase-like, and the antioxidant nanozymes. Each of these classes catalyzes a specific group of reactions. With the development of nanoscience and nanotechnology, the variety of applications for nanozymes in diverse fields has expanded dramatically, with the most popular applications in biosensing. Nanozyme-based novel biosensors have been designed to detect ions, small molecules, nucleic acids, proteins, and cancer cells. The current review focuses on the catalytic mechanism of nanozymes, their application in biosensing, and the identification of future directions for the field. Full article

The outstanding properties of metal nanoclusters, stabilized with different scaffolds, i.e., proteins, nucleic acids, polymers and dendrimers, enable their application in a wide range of fields. The recent advances in the fabrication and synthesis of nanoclusters have revolutionized the design of biosensors, leading to significant improvements in the selective and sensitive determination of several targets. In particular, in recent years, copper nanoclusters (CuNCs) have attracted more attention mainly for their unique fluorescent properties, as well as their large Stokes shifts, low toxicity, and high biocompatibility. The high-photoluminescent features of CuNCs facilitate highly sensitive target detection even in complex biological matrices. For these reasons, in this work, we exploited the specific template-targeted CuNCs’ growth for the sensitive and accurate determination of human serum albumin (HSA) in urine and human serum. HSA is the most abundant protein in plasma, acting as a carrier for many key biological molecules such as hormones, fatty acids and steroids, and it contributes to the maintenance of the oncotic blood pressure. The concentration of HSA in body fluids greatly influences the state of health of the patients. Taking into account these considerations, the quantitative detection of human serum albumin plays a key role in the early diagnosis of serious pathological conditions such as albuminuria and albuminemia. Here, we present a CuNCs-based assay in which copper nanoclusters were used as fluorescent signal indicators to detect serum albumin in a complex biological matrix. Full article