Hybrid Nanobioengineered Nanomaterial-Based Electrochemical Biosensors.

Nanoengineering biosensors have become more precise and sophisticated, raising the demand for highly sensitive architectures to monitor target analytes at extremely low concentrations often required, for example, for biomedical applications. We review recent advances in functional nanomaterials, mainly based on novel organic-inorganic hybrids with enhanced electro-physicochemical properties toward fulfilling this need. In this context, this review classifies some recently engineered organic-inorganic metallic-, silicon-, carbonaceous-, and polymeric-nanomaterials and describes their structural properties and features when incorporated into biosensing systems. It further shows the latest advances in ultrasensitive electrochemical biosensors engineered from such innovative nanomaterials highlighting their advantages concerning the concomitant constituents acting alone, fulfilling the gap from other reviews in the literature. Finally, it mentioned the limitations and opportunities of hybrid nanomaterials from the point of view of current nanotechnology and future considerations for advancing their use in enhanced electrochemical platforms.

Peptide-based simple detection of SARS-CoV-2 with electrochemical readout.

Coronavirus disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is considered one of the worst pandemic outbreaks worldwide. This ongoing pandemic urgently requires rapid, accurate, and specific testing devices to detect the virus. We report a simple electrochemical biosensor based on a highly specific synthetic peptide to detect SARS-CoV-2 Spike protein. Unlike other reported electrochemical biosensors involving nanomaterials or complex approaches, our electrochemical platform uses screen-printed gold electrodes functionalized with the thiolated peptide, whose interaction with the Spike protein is directly followed by Electrochemical Impedance Spectroscopy. The electrochemical platform was Spike protein concentration-dependent, with high sensitivity and reproducibility and a limit of detection of 18.2 ng/mL when tested in Spike protein commercial solutions and 0.01 copies/mL in lysed SARS-CoV-2 particles. The label-free biosensor successfully detected the Spike protein in samples from infected patients straightforwardly in only 15 min. The simplicity of the proposed format combined with an on-demand designed peptide opens the path for detecting other pathogen-related antigens.

Structure-activity relationships on the study of ß-galactosidase folding/unfolding due to interactions with immobilization additives: Triton X-100 and ethanol.

Improving the enzyme stability is a challenge for allowing their practical application. The surfactants are stabilizing agents, however, there are still questions about their influence on enzyme properties. The structure-activity/stability relationship for ß-galactosidase from Bacillus circulans is studied here by Circular Dichroism and activity measurements, as a function of temperature and pH. The tendency of preserving the ß-sheet and α-helix structures at temperatures below 65°C and different pH is the result of the balance between the large- and short-range effects, respecting to the active site. This information is fundamental for explaining the structural changes of this enzyme in the presence of Triton X-100 surfactant and ethanol. The enzyme thermal stabilization in the presence of this surfactant responds to the rearrangement of the secondary structure for having optimal activity/stability. The effect of ethanol is more related with changes in the dielectric properties of the aqueous solution than with protein structural transformations. These results contribute to understand the effects of surfactant-enzyme interactions on the enzyme behavior, from the structural point of view and to rationalize the surfactant-based stabilizing strategies for ß-galactosidades.

Equilibrio trabajo-familia: corresponsabilidad familiar y autoeficacia parental en trabajadores de una empresa chilena / Work-Family Balance: Working Family and Parental Self-Efficacy in Chilean Company Workers

En el artículo se analizan las diferencias entre equilibrio trabajo-familia, corresponsabilidad y autoeficacia parental en trabajadores de una empresa chilena. A 224 trabajadores les fueron aplicados tres instrumentos: el cuestionario de interacción trabajo-familia, el cuestionario de participación en el trabajo familiar y la escala de autoeficacia parental. Se observa que no existe diferencia en el nivel de equilibrio trabajo-familia entre hombres y mujeres (t [222] = -0,83, p > 0,05). En corresponsabilidad se evidencian diferencias estadísticamente significativas (t [220,28] = -7,27, p < 0,05), indicando que las mujeres realizan más tareas en el hogar, a pesar de su jornada laboral. En relación con la autoeficacia parental existen diferencias entre hombres y mujeres (t [215] = -8,76, p <0,05), indicando que las mujeres se perciben a sí mismas como mejores madres.

This article analyzes the differences between work-family balance, joint responsability and parental self-efficacy in employees of a Chilean company. 224 professional workers were administered three instruments: the work-family interaction questionnaire, the participation in family work questionnaire and the parental self-efficacy scale. It is observed that there is no difference in the level of work-family balance between men and women (t [222] = -0.83, p > 0,05). On joint responsibility, there are evident statistically differences (t [220,28] = -7,27, p < 0,05), indicating that women do more housework, despite their working day. Regarding parental self-efficacy, there are differences between men and women (t [215] = -8,76 p < 0,05), indicating that women perceive themselves as better mothers.