Real-Time Intracellular Monitoring of miRNA Dynamics during Induced Pluripotent Stem Cell Neuronal Differentiation via Plasmon-Enhanced Nanobiosensing

Induced pluripotent stem cells (iPSCs) offer immense potential for treating central nervous system (CNS) disorders and injuries. However, the lack of highly sensitive, selective, and noninvasive biosensors for real-time monitoring of iPSC neuronal differentiation remains a critical barrier. In this work, we introduce a gold nanorod-based metal-enhanced molecular beacon (MEMB) nanobiosensor for the noninvasive, real-time detection of intracellular miRNA-124, a key biomarker for neuronal differentiation in human iPSC-derived neural stem cells. Designed through finite-difference time-domain (FDTD) simulations and experimentally validated for optimized localized surface plasmon resonance (LSPR) properties, MEMB nanobiosensors achieved picomolar-level sensitivity and single-mismatch selectivity toward miRNA-124 detection, along with great biocompatibility demonstrated by live-cell assays. Collectively, the MEMB platform provides a robust analytical tool for in-depth investigations of molecular and genetic regulatory networks during iPSC neuronal differentiation in a nondestructive manner, paving the way toward safer, more efficient, and better-characterized iPSC-derived cell therapies for CNS diseases and injuries.