The p53 gene— “the guardian of the genome”—is responsible for maintaining the integrity of the genome, along with cell cycle regulation, apoptosis, and cell differentiation. New analytical devices are needed to recognize the main alterations this gene could suffer, since it is one of the most frequent in human cancer. For this reason, we developed an electrochemical DNA biosensor with high sensitivity and specificity to monitor the 175p2 mutation of the p53 gene. We modified a screen-printed gold electrode (SPGE) by immobilizing a thiolated DNA probe sequence with 11-mercaptoundecanoic acid to detect its complementary sequence through the hybridization reaction. Doxorubicin (Dox) was used to increase the sensitivity of the biosensor, and the entire process was evaluated using the Cyclic Voltammetry (CV) technique. The measurement range of the developed device is from 1 fM to 100 nM of the p53 gene mutation with a limit of detection (LOD) of 2.2 fM. In the presence of Dox, the LOD increased up to 175 aM, becoming one of the highest efficiency devices in the field. The electrochemical DNA biosensor selectively detects the p53 suppressor gene mutation; it distinguishes between different non-complementary and complementary sequences. Our results indicate a high potential of our sensor for the p53 gene 175p2 mutation detection, which is convenient in the early diagnosis of diseases related to this gene. Resumen. El gen p53—“guardián del genoma”—es responsable de mantener la integridad del genoma, así como de la regulación del ciclo celular, la apoptosis, y la diferenciación celular. Es necesario desarrollar nuevos dispositivos analíticos para reconocer las principales alteraciones que este gen podría sufrir, ya que es uno de los más frecuentes en el cáncer humano. En este sentido, se desarrolló un sensor electroquímico de ADN de alta sensibilidad y especificidad para identificar la mutación 175p2 del gen p53. Para ello, se formó una monocapa sobre un electrodo de oro que contenía secuencias sonda de ADN tiolado junto con ácido 11-mercaptoundecanoico, las cuales se emplearon para detectar la mutación del gen a través de la reacción de hibridación. Finalmente, se utilizó doxorrubicina (Dox) para aumentar la sensibilidad del biosensor; el proceso se evaluó mediante la técnica de Voltamperometría Cíclica (VC). El rango de medición del dispositivo desarrollado es de 1 fM a 100 nM de la mutación del gen p53 con un límite de detección (LOD) de 2.2 fM. En presencia de Dox, el LOD aumentó hasta 175 aM, convirtiéndose en uno de los dispositivos de mayor eficiencia en el campo. El biosensor electroquímico de ADN detecta selectivamente la mutación del gen supresor p53 y es capaz de distinguir entre diferentes secuencias complementarias y no complementarias. Nuestros resultados indican un alto potencial del biosensor para la detección de la mutación 175p2 del gen p53, lo cual es conveniente en el diagnóstico oportuno de enfermedades relacionadas con este gen.

We propose a model for studying binary fluids based on the mesoscopic molecular simulation technique known as multiparticle collision, where the space and state variables are continuous, and time is discrete. We include a repulsion rule to simulate segregation processes that does not require calculation of the interaction forces between particles, so binary fluids can be described on a mesoscopic scale. The model is conceptually simple and computationally efficient; it maintains Galilean invariance and conserves the mass and energy in the system at the micro- and macro-scale, whereas momentum is conserved globally. For a wide range of temperatures and densities, the model yields results in good agreement with the known properties of binary fluids, such as the density profile, interface width, phase separation, and phase growth. We also apply the model to the study of binary fluids in crowded environments with consistent results.