Gold-graphene based nanofiber biosensor for selective electrochemical identification of CD105-positive canine mesenchymal stem cells.

Mesenchymal stem cells (MSCs) have great potential for use in regenerative medicine owing to their multipotent characteristics and immunomodulatory properties; however, maintaining their cell surface phenotype and stemness during their in-vitro culture is one of the major challenges. To adress this issue an electrochemical biosensor has been developed for the detection of MSCs based on the expression of their surface marker CD105. This device has been fabricated through the process of electrospinning of PCL-gelatin nanofibers incorporated with AmGn and AuNPs composites to create a conductive interface. Also, the nanofibrous composite created an increase in electroactive area and improved cell-electrode interactions, while EDC/NHS coupling chemistry enabled stable and covalent immobilization of CD105 Ab. The biosensor demonstrated a linear and proportional electrochemical response to MSCs over the range of 78 - 10,000 cells, with a practical detection limit of 312 cells. The device showed negligible cross reactivity and was validated using fluorescence-activated cell sorting (FACS) analysis to confirm the sensor's reliability and accuracy. The biosensor remained above 70% of the initial response after two weeks of storage at 4 °C, indicating moderate stability of the biosensor. This device presents a sensitive and selective approach for CD105 positive canine MSC detection, offering a promising tool for quality control in cell-based therapeutic applications.