Semiconductors have great potential as surface-enhanced Raman scattering (SERS) substrates due to their excellent physiochemical properties. However, they provide low signal enhancements relative to their plasmonic counterparts, which necessitates innovation in their synthesis and application. Substitutional atomic doping is proposed to improve SERS enhancement by controlling electronic properties, such as the band gap. In this work, zinc oxide (ZnO) nanoparticles were synthesized by co-precipitation and doped with magnesium (Mg) at concentrations ranging from 2–10%. Nanoparticle morphology and size were obtained by scanning electron microscopy (SEM). Elemental composition and chemical states were determined using X-ray photoelectron spectroscopy (XPS). Optical properties were obtained with a UV-vis spectrophotometer, while a Raman spectrometer was used to acquire Raman signal enhancements. Stability was assessed by UV-vis spectroscopy, while cytotoxicity was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The results showed that the absorption edge of Mg-doped ZnO nanoparticles was red-shifted compared to pure ZnO nanoparticles. The band gap decreased (3.3–3.01 eV) with increasing Mg doping, while the highest Raman enhancement was observed at 2% doping. No significant cytotoxic effects were observed at low concentrations (3–12 μg/mL). Overall, this study provides evidence for the tunability of ZnO substrates and may serve as a platform for applications in molecular biosensing.

Developing a biomolecular detection method that minimizes photodamage while preserving an environment suitable for biological constituents to maintain their physiological state is expected to drive new diagnostic and mechanistic breakthroughs. In addition, ultra-sensitive diagnostic platforms are needed for rapid and point-of-care technologies for various diseases. Considering this, surface-enhanced Raman scattering (SERS) is proposed as a non-destructive and sensitive approach to address the limitations of fluorescence, electrochemical, and other optical detection techniques. However, to advance the applications of SERS, novel approaches that can enhance the signal of substrate materials are needed to improve reproducibility and costs associated with manufacture and scale-up. Due to their physical properties and synthesis, semiconductor-based nanostructures have gained increasing recognition as SERS substrates; however, low signal enhancements have offset their widespread adoption. To address this limitation and assess the potential for use in biological applications, zinc oxide (ZnO) was coated with different concentrations (0.01–0.1 M) of gold (Au) precursor. When crystal violet (CV) was used as a model target with the synthesized substrates, the highest enhancement was obtained with ZnO coated with 0.05 M Au precursor. This substrate was subsequently applied to differentiate exosomes derived from three cell types to provide insight into their molecular diversity. We anticipate this work will serve as a platform for colloidal hybrid SERS substrates in future bio-sensing applications.

The frequent use of antibiotics has created favorable conditions for bacteria to develop resistance. Bacterial resistance is an issue for global health killing at least 1 million people worldwide annually. The quest for new and effective antimicrobials with activities against resistance bacteria demands immediate attention. The use of nanoparticles as antimicrobials alternatives to conventional antibiotics may have the potential to combat bacterial resistance. Silver nanoparticles, silver nanoparticles have captivated the interest of most researchers by virtue of their broad-range antimicrobial activity against bacteria due to their strong biocidal effect against microorganisms. Silver nanoparticles have been traditionally synthesized by physical chemical and biological process. However, biosynthesis of silver nanoparticles from wings of carpenter bees Xylocopa virginica, which is abundantly available in summer in the United States of America, is yet to be explored. Herein, we report the synthesis of silver nanoparticles using wing extract of carpenter bees X. virginica. Subsequently the biosynthesized nanoparticles were characterized by UV–Visible absorption spectroscopy and scanning electron microscopy (SEM). Furthermore, the antimicrobial activity of the biosynthesized nanoparticles was investigated against two common Gram-negative and Gram-positive pathogenic bacteria viz Klebsiella pneumonia, Escherichia coli, Micrococcus luteus and Staphylococcus aureus using microdilution method. The results of this study indicate that biosynthesized silver nanoparticles from X. virginica wing extract showed an absorption band at 440 nm and SEM revealed spherical nanoparticles 20- 60 nm in size. Additionally, biosynthesizes silver nanoparticles from the wings of X. virginica exhibited antimicrobial activity against all the tested bacteria signifying their biomedical, pharmaceutical, and agricultural potential.

MicroRNAs (miRNAs) play critical regulatory roles in diverse biological processes and are key biomarkers in a wide range of physiological and pathological conditions, including cancer. However, their inherently low concentrations in biological samples pose a major challenge for reliable detection and quantification. To overcome this limitation, we developed a fluorescence‐based biosensing platform that integrates rolling circle amplification (RCA) and multi‐primed chain amplification (MCA) to enhance signal and detection sensitivity. The system is engineered to allow flexible reconfiguration for different miRNA targets by altering probe and primer sequences. In this modular system, miR‐i, a miRNA commonly expressed in healthy and cancerous samples, serves as a universal initiator for RCA. Signal amplification was subsequently driven by hybridization with two randomly selected miRNAs (miR‐A and miR‐D), enabling evaluation of system performance under varied input conditions. Fluorescence emission was measured following the addition of a molecular beacon and subsequent spectrofluorometric analysis. The biosensor exhibited a strong linear correlation between miRNA concentration and fluorescence intensity, achieving a limit of detection (LOD), and limit of quantification (LOQ) below 10 pM in both buffer and human serum. These findings demonstrate the platform's high sensitivity and robustness. Importantly, modular architecture allows for easy reconfiguration to detect a wide array of miRNAs or other non‐coding RNAs, positioning this platform as a broadly applicable tool for molecular diagnostics beyond any specific disease context.

Background: Triple‐negative breast cancer (TNBC), a leading cause of female mortality worldwide, presents a treatment challenge due to the lack of targeted receptors. Macrophages, recognized for their role in the immune response, provide a promising avenue for cancer research. Given that macrophages secrete extracellular particles (EPs), which have been implicated in biological processes, including intercellular communication and immune modulation, it is hypothesized that EPs derived from macrophages could have potential anticancer effects.Aims: This study examines the effect of M1 macrophage‐secreted EPs on TNBC cells to investigate their potential as a therapeutic.Methods and Results: Polarization was induced in RAW 264.7 macrophages and characterized using ELISA, nitrite release, and microscopy. Macrophage‐derived EPs were isolated and characterized using nanoparticle tracking analysis, electron microscopy, and western blotting. The influence of EPs on MDA‐MB‐231 cells, a TNBC model, was assessed using confocal microscopy. Results showed the increasing expression of caspase 3/7 in a time‐dependent manner (0, 24, and 48 h). Cell death was observed in TNBC cells with M1 macrophage‐derived EPs, while cell proliferation was observed when M2 macrophage‐derived EPs interacted with MDA‐MB‐231 cells.Conclusion: Overall, results showed that EPs derived from M1 macrophages could induce cell death in MDA‐MB‐321 cells, opening up potential options for new treatments in TNBC.

Developing a biomolecular detection method that minimizes photodamage while maintaining an environment suitable for biological constituents to maintain their physiological state is expected to drive new diagnostic and mechanistic breakthroughs. In addition, ultra-sensitive diagnostic platforms are needed for rapid and point-of-care technologies for various diseases. Considering this, surface-enhanced Raman scattering (SERS) is proposed as a non-destructive and sensitive approach to address the limitations of fluorescence, electrochemical, and other optical detection techniques. However, to advance the applications of SERS, novel approaches to enhance the signal of substrate materials are needed to improve reproducibility and costs associated with manu-facture and scale-up. Due to their physical properties and synthesis, semiconductor-based nanostructures have gained increasing recognition as SERS substrates; however, low signal en-hancements have offset their widespread adoption. To address this limitation and assess the po-tential for use in biological applications, zinc oxide (ZnO) was coated with different concentra-tions (0.01-0.1 M) of gold (Au) precursor. When crystal violet (CV) was used as a model target with the synthesized substrates, the highest enhancement was obtained with ZnO coated with 0.05 M Au precursor. This substrate was subsequently applied to differentiate exosomes derived from three cell types to provide insight into their molecular diversity. We anticipate this work will serve as a platform for colloidal hybrid SERS substrates in future bio-sensing applications.