A research team at Rutgers University has developed a biosensor technology that could benefit applications for the treatment of neurological disorders through stem cell therapy. The hybrid biosensing platform consists of an array of ultrathin graphene layers and gold nanostructures. This platform has been combined with Raman spectroscopy to detect genes and characterize different kinds of stem cells with greater reliability, selectivity, and sensitivity. Because stem cells can become many different types of cells, stem cell therapy shows promise for regenerative treatment of neurological disorders in which diseased cells require replacement or repair. However, a way to characterize stem cells and control their fate is needed. This biosensing platform consists of an array of ultrathin graphene layers and gold nanostructures. Combined with Raman spectroscopy, it detects genetic material and characterizes different kinds of stem cells with greater reliability, selectivity, and sensitivity. Courtesy of Letao Yang, KiBum Lee, Jin-Ho Lee, and Sy-Tsong (Dean) Chueng. The new biosensor monitors the fate of stem cells by detecting genetic material (RNA) involved in turning stem cells into neurons. The graphene-coated plasmonic metal nanoarrays that are used for the sensing platform synergize both electromagnetic mechanism (EM)- and chemical mechanism (CM)-based enhancements. The plasmonic nanostructures make it possible to obtain a highly reproducible enhancement of Raman signals via a strong, uniform EM. Simultaneously, the graphene-functionalized surface of the platform amplifies the Raman signals by an optimized CM, increasing the sensitivity and accuracy of the system. Using the dual-enhanced Raman scattering from both EM (from the nanoarray) and CM (from the graphene surface), the researchers detected and quantified a specific biomarker’s (TuJ1) gene expression levels to characterize neuronal differentiation of human neural stem cells (hNSCs). “A critical challenge is ensuring high sensitivity and accuracy in detecting biomarkers — indicators such as modified genes or proteins — within the complex stem cell microenvironment,” professor KiBum Lee said. “Our technology, which took four years to develop, has demonstrated great potential for analyzing a variety of interactions in stem cells.” The Rutgers-led team’s biosensor technology could help lead to safe stem cell therapies for treating Alzheimer’s and Parkinson’s diseases and other neurological disorders. The research was published in Nano Letters (www.doi.org/10.1021/acs.nanolett.9b03402).