A gold@graphene oxide biosensor based on plasmon-enhanced fluorescent and fret for intracellular detection of microRNA in differentiating T cells

Abstract

Microribonucleic acid (miRNA) is a class of small single-strand RNA which controls cellular processes such as differentiation and apoptosis by undergoing gene silencing. Recent studies provoke a new insight that miRNA is likely playing, suggesting that miRNA is likely a crucial regulator in T cell subtype differentiation. Numerous miRNA profiling studies showed the expression level of miRNA changes during different differentiated states of CD8+ T-cells. MiRNAs such asmiR-21 and miR-150 dominantly expressed and exhibited profound changes in gene expression between naïve, effector, and memory CD8+ T-cells. However, limited studies have attempted to trace T-cell differentiation from a miRNA perspective, which may provide novel insights into miRNA functions and potential therapeutic applications for future fundamental studies relating to T-cell immunotherapy. This study successfully developed a metal-enhanced fluorescence (MEF) nucleic acid-based nanoprobe to explore T-cell subtypes by sensing miRNA-150 and miRNA-21 on day 0, 1, 3, 5 and 7. The optimal MEF distance was approximately 18 nm with an enhancement factor of 2.8 times for FITC and 1.8 times for RITC. Notably, we further fortified these nanoparticles with a secondary silica coating layer, enhancing stability greatly for 21 days. These nanoprobes displayed a linear response to varying target DNA concentrations, boasting limits of detection (LoD) at a remarkable 28.859 pM for FITC-coated AuSiO2 and 38.43 pM for RITC-coated AuSiO2.