Adrian Martinez-Rivas

Two-dimensional transition metal dichalcogenides (2D TMDs) show great potential for next generation optoelectronic devices due to their efficient exciton dissociation and rapid charge transfer. However, the large-area synthesis of uniform ultrathin films with controlled morphology remains challenging. Here, we report a Langmuir–Blodgett (LB) approach for the controlled deposition of MoS₂ and WS₂ films on silicon and α-Al₂O₃ substrates. Surface pressure–area (π–A) isotherms reveal a strong substrate dependence, with larger molecular areas and lower collapse pressures on Si compared to Al₂O₃. Atomic force microscopy confirms the formation of monolayer MoS₂ on both substrates, while WS₂ exhibits bilayer growth on Si and multilayer stacking on Al₂O₃. SEM further supports the substrate-induced morphological evolution. Raman spectroscopy demonstrates a clear thickness dependence of vibrational modes, while resonant Raman measurements under 632 nm excitation reveal enhanced electron–phonon coupling in MoS₂. X-ray diffraction confirms the hexagonal 2H phase and preferential (002) orientation.

This study explores the integration of reduced graphene oxide (rGO) into an optoelectronic XOR logic gate to enhance BB84 protocol encryption in quantum communication systems. The research leverages the nonlinear optical properties of rGO, specifically its nonlinear refraction characteristics, in combination with a Michelson interferometer to implement an optoelectronic XOR gate. rGO samples were deposited using the Langmuir–Blodgett technique and characterized in morphology and structure. The optical setup utilized a frequency-modulated laser signal for the interferometer and a pulsed laser system that generates the quantum information carrier. This integration of quantum encryption with nonlinear optical materials offers enhanced security against classical attacks while providing adaptability for various applications from secure communications to quantum AI.

In this work, we studied the impact of magnetic nanoparticles (MNPs) interactions with HeLa cells when they are exposed to high frequency alternating magnetic field (AMF). Specifically, we measured the nanobiomechanical properties of cell interfaces by using atomic force microscopy (AFM). Magnetite (Fe ₃ O ₄ ) MNPs were synthesized by coprecipitation and encapsulated with silica (SiO ₂ ): Fe ₃ O ₄ @SiO ₂ and functionalized with amino groups (−NH ₂ ): Fe ₃ O ₄ @SiO ₂ –NH ₂ , by sonochemical processing. HeLa cells were incubated with or without MNPs, and then exposed to AMF at 37 °C. A biomechanical analysis was then performed through AFM, providing the Young’s modulus and stiffness of the cells. The statistical analysis ( p < 0.001) showed that AMF application or MNPs interaction modified the biomechanical behavior of the cell interfaces. Interestingly, the most significant difference was found for HeLa cells incubated with Fe ₃ O ₄ @SiO ₂ –NH ₂ and exposed to AMF, showing that the local heat of these MNPs modified their elasticity and stiffness.