Point-of-Care Electrochemical Immunosensor Applied against Nosocomial Infection: Staphylococcus aureus Detection in Human Hand Skin.

Staphylococcus aureus is an important pathogen that causes nosocomial infections, resulting in unacceptable morbidity and mortality rates. In this work, we proposed the construction of a nanostructured ZnO-based electrochemical immunosensor for qualitative and semiquantitative detection of S. aureus using simple methods for growing zinc oxide nanorods (ZnO NRs) on a sensor board and immobilizing the anti-S. aureus antibody on ZnO NRs through cystamine and glutaraldehyde. The immunosensor detected S. aureus in the 103-107 colony-forming unit (CFU) mL-1 range and showed a limit of detection (LoD) around 0.792 × 103 CFU mL-1. Beyond a satisfactory LoD, the developed immunosensor presented other advantages, such as high versatility for point-of-care assays and a suitable selective factor that admits the detection of the S. aureus concentration range in human hand skin after washing. Moreover, the immunosensor showed the potential to be an excellent device to control nosocomial infection by detecting the presence of S. aureus in human hand skin.

Early diagnosis of Zika infection using a ZnO nanostructures-based rapid electrochemical biosensor.

In this work, we report a develop of electrochemical immunosensor based on ZnO nanostructures immobilized with ZIKV-NS1 antibody on Printed Circuit Board (PCB). ZnO nanostructures were grown on PCB by chemical bath deposition (CDB) and characterized by SEM. ZIKV-NS1 antibody was immobilized on the ZnO nanostructures surface via cystamine and glutaraldehyde. The samples were characterized by Immunofluorescence Confocal Microscopy and FTIR to identify the immobilization of the antibody to the sensor board. The analytical responses of the immunosensor were evaluated by Cyclic Voltammetry (CV). The biosensor developed here allows rapid detection of Zika virus in undiluted urine, without cross reactive with DENV-NS1 antigen, with linear range 0.1  ng mL-1 to 100 ng mL-1. The limit of detection is lower than 1.00 pg  mL-1. The biosensor is portable, cost-effectiveness, and simple to use, which makes it ideal for point-of-care applications.

Effects of aggrecan on schwann cell migration in vitro and nerve regeneration in vivo

Although the role of many small proteoglycans in regeneration of the nervous system has been established, little is known about the involvement of large proteoglycans. In this study, we evaluated the effects of aggrecan, a high molecular mass proteoglycan, on Schwann cells in vitro and investigated its effects on axonal regeneration after sciatic nerve tubulization. The number of regenerated axons and their morphometrical parameters were determined in vivo. Aggrecan increased the number and viability of Schwann cells in vitro. Similarly, the number of regenerated fibers increased significantly when aggrecan was applied in vivo, but there were no alterations in the morphometrical parameters. These results indicate that aggrecan contributes to the regeneration of peripheral axons and has a positive effect on the Schwann cells.