https://hdl.handle.net/10481/47597 Sat, 11 Apr 2026 12:54:53 GMT 2026-04-11T12:54:53Z https://hdl.handle.net/10481/112081 Protein-Directed Nucleation and Stabilization of Ultrasmall Silver Nanoparticles Within BSA Hydrogels Salto Girón, Carmen; Gonzalez-Garcia, M. Carmen; Mañas Torres, María del Carmen; López López, Modesto Torcuato; Álvarez de Cienfuegos, Luis; Hueso, Jose L.; Orte Gutiérrez, Ángel; García Fernández, Emilio Biocompatible nanocomposite hydrogels are emerging as versatile platforms in nanomedicine, particularly when natural proteins are used as both structural and chemical components. In this work, we report a green, simple, and rapid in situ synthesis of ultrasmall silver nanoparticles (uAgNPs) within a bovine serum albumin (BSA) hydrogel, in which albumin simultaneously acts as the reducing agent and three-dimensional scaffold. The confined reaction environment generated uniformly dispersed Ag nanostructures with diameters in the 4–40 nm range, as confirmed by DLS and TEM. High-resolution TEM revealed clear Face-Centered Cubic (FCC, 111) lattice fringes, demonstrating the crystalline nature of the embedded uAgNPs. Quantitative image analysis showed narrow size distributions and high circularities, consistent with cluster stabilization through protein–metal interactions. Rheological measurements further indicated that the incorporation of uAgNPs enhanced hydrogel stiffness and delayed yielding, reflecting a reinforcement effect mediated by the nanoparticles acting as additional cross-linking points. Moreover, when very small embedded uAgNPs are formed, the presence of emissive silver nanoclusters was found using fluorescence emission spectroscopy. Overall, our results show that BSA hydrogels provide an effective matrix for directing green uAgNP nucleation, ensuring high stability, controlled growth in less than 2 min, and improved mechanical properties. The resulting protein–nanoparticle composite constitutes a promising soft material for imaging, sensing, and other biomedical applications requiring stable, biocompatible nanoscale architectures. https://hdl.handle.net/10481/112081 https://hdl.handle.net/10481/111473 Flour moisture detection with an europium-based luminescent probe Fueyo-González, Francisco; Cenit, Anabel; Villodrés, Rocío; Saiz, Ignacio; Micolonghi, Giulia; Talavera Rodríguez, Eva María; Teychené, Sébastien; Rodríguez-Ruiz, Isaac; Herranz, Rosario; Orte Gutiérrez, Ángel; García Fernández, Emilio; González Vera, Juan Antonio In this work, we describe the application of the self-assembled europium complex 1:Eu(III) (where 1: diethyl 8-methoxy-2-oxo-1,2,4,5-tetrahydro-cyclopenta[de]quinolin-3-yl)phosphonate) for the analysis of water content of wheat flour. The methodology herein described represents a robust and accurate way for the detection of small amounts of water in food, providing comparing results with well-established methods such as thermogravimetry and Karl-Fischer titration. Interestingly, as an advantage over other methods, our luminescence-based approach can be implemented in lab-on-a-chip microfluidic devices for real-time and on-line detection of water content of food samples. Additionally, the remarkably long luminescence lifetime of Eu(III) allows the use of state-of-the-art imaging strategies based on PLIM microscopy for the direct visualization of unique water content maps of wheat flour particles. This work was supported by grants grant PID2020–114256RB-I00 funded by AEI/10.13039/501100011033; grant PID2019–104366RB-C22 funded by AEI/10.13039/501100011033/FEDER “Una manera de hacer Europa”; and grants P21_00212 and A-FQM-386-UGR20 funded by FEDER/Junta de Andalucía-Conserjería de Transformación Económica, Industria, Conocimiento y Universidades. We acknowledge the Centro de Instrumentación Científica (CIC) of Universidad de Granada for the thermogravimetric measurements. https://hdl.handle.net/10481/111473 https://hdl.handle.net/10481/111456 Multiplexed MicroRNA biomarker detection by bridging lifetime filtering imaging and dynamic chemical labeling Padial-Jaudenes, Maria; Tabraue-Chavez, Mavys; Detassis, Simone; Ruedas-Rama, Maria Jose; González García, María del Carmen; Fara, Mario Antonio; López-Delgado, Francisco Javier; González Vera, Juan Antonio; Guardia-Monteagudo, Juan Jose; Diaz-Mochon, Juan Jose; García Fernández, Emilio; Pernagallo, Salvatore; Orte Gutiérrez, Ángel MicroRNAs (miRs) have emerged as promising biomarkers for early disease diagnosis and personalized treatment monitoring. However, their clinical utility has been hampered by technical limitations. Dynamic chemical labeling (DCL) based on capturing abasic PNA probes and reactive nucleobases, known as SMART bases, is a PCR-free approach that has proven very useful for the direct interrogation of circulating miRs. In this work, we expand the palette of tools available for the detection of DCL miR by synthesizing a new SMART nucleobase called SMART-C-Eu. This nucleobase contains a stable lanthanide cryptate. Using this SMART-C-Eu base and time-gated (TG) luminescence imaging, we successfully detect and quantify miR-122–5p in human serum samples. miR-122–5p is a well-known biomarker for drug-induced liver injury. Through a bead-counting analysis approach, statistical robustness is improved and miR-122–5p concentrations are detected in the nanomolar range. Furthermore, we extend this approach to multiplexed detection of three different miRs (miR-371a-3p, miR-451a-5p, and miR-122–5p) using spectral and temporal filtering. Importantly, we designed a user-independent multiplexed analysis using machine learning algorithms for automatic bead classification. Although the sensitivity of this technique must be further improved to detect miRs at lower concentrations, the method represents a significant advancement in miR analysis by combining ML segmentation using lifetime and intensity images. In addition, the technique offers multiplexing capabilities and the potential for automation, paving the way for more accurate and robust clinical applications in the future. https://hdl.handle.net/10481/111456 https://hdl.handle.net/10481/110860 Self-assembled luminescent lanthanide complexes in solution as rising stars for sensing and bioimaging Ruiz Arias, Álvaro; Fueyo-Gonzalez, Francisco; Orte Gutiérrez, Ángel; González Vera, Juan Antonio Luminescent lanthanide (Ln3+) complexes are highly attractive for diverse applications, particularly as luminescent probes, owing to their exceptional photophysical properties, including long-lived photoluminescence, narrow-band emissions, and large Stokes shifts. These characteristics enable advanced techniques like time-gated detection, significantly enhancing signal-to-noise ratios in biological samples. Traditional luminescent Ln3+ complexes are characterized by bulky organic cryptands and/or conjugated chromophoric antennae for prompting the metal excitation prior to emission. This strategy is usually synthetically demanding, including complexation reactions that last for several days. To overcome this limitation, self-assembly strategies in solution have recently emerged as a powerful approach. This review discusses recent advancements in self-assembled luminescent Ln3+ complexes across various solvents, with particular emphasis on their behavior and performance in aqueous environments. It highlights the growing importance of water-compatible self-assembled luminescent Ln3+ complexes for biological applications, underscoring their potential in cell imaging and biosensing. By addressing key design challenges and showcasing diverse functionalities, this review provides a comprehensive and accessible overview for researchers in chemistry, biochemistry, and biology interested in the rapidly evolving field of lanthanide luminescence. https://hdl.handle.net/10481/110860 https://hdl.handle.net/10481/110269 Orthogonal Cell Polarity Imaging by Multiparametric Fluorescence Microscopy González García, María del Carmen; Peña-Ruiz, Tomás; Herrero-Foncubierta, Pilar; Miguel Álvarez, Delia; Girón González, María Dolores; Salto González, Rafael; Cuerva Carvajal, Juan Manuel; Navarro, Amparo; García Fernández, Emilio; Orte Gutiérrez, Ángel The cellular microenvironment is a complex medium due to high concentrations of proteins and an intertwined framework of cellular organelles. In particular, cellular micro-polarity controls several biological processes, since it modulates hydrophobic/hydrophilic interactions and, hence, recognition, signalling and binding events. In this work, we have developed an unprecedented methodology to construct accurate environment polarity images using multiparametric fluorescence microscopy, via a multi-linear calibration of orthogonal parameters: the fluorescence lifetime and the spectral shift of a series of solvatochromic dyes. For this approach, we have synthesized and fully characterized N-substituted 2-methoxy-9-acridone dyes as suitable bioimaging polarity probes. However, to fully comprehend the complex links between microenvironment polarity and the dyes’ properties, we have endeavoured a multidisciplinary approach, in which we have studied the photophysics of our fluorophores using spectroscopic tools and state-of-the-art computational chemistry. This profound knowledge permitted to use these dyes as intracellular polarity probes, quantitatively and robustly probing the microenvironment of different cellular compartments. Our new methodology may pave the way to further developments in accurate sensing of cellular microenvironment parameters. This work has been funded by grants CTQ2017-85658-R and CTQ2017-86125-P (MICIU/AEI/ERDF)), FQM-337 (Junta de Andalucía), and 1_PIUJA 2017-18 (Universidad de Jaén). We acknowledge the Universidad de Granada (Spain) microscopy central facilities (CICUGR) and computing time from CSIRC-UGR. MCGG thanks MICIU/AEI for a predoctoral fellowship. https://hdl.handle.net/10481/110269