DNA Aptamer-Modified Glass Nanopores for Intracellular Dopamine Detection with Improved Sensitivity and Stability

Detecting intracellular dopamine is crucial to understanding neurodegenerative diseases. In this article, we proposed a nanopore sensor utilizing DNA aptamer probes to specifically interact with dopamine, enabling detection of intracellular dopamine in a single pheochromocytoma (PC12) cell. Two different aptamers were designed, and one with higher sensitivity and stability was chosen for the current testing. The nanopore sensor demonstrated a detection limit of 0.92 nM and a wide detection range of 1 nM to 100 μM. The sensor had a response time of ∼15 s upon the addition of 1 μM dopamine and was reversible and reusable (>6 days) with salt gradient enhancement. As a demonstration, the sensor was used for detecting dopamine concentration changes in PC12 cells in response to L-DOPA at different concentrations.