DNA-stabilized silver nanoclusters as specific, ratiometric fluorescent dopamine sensors

Abstract

Neurotransmitters are small molecules that orchestrate complex patterns of brain activity. Unfortunately, there exist few sensors capable of directly detecting individual neurotransmitters. Those sensors that do exist are either unspecific or fail to capture the temporal or spatial dynamics of neurotransmitter release. DNA-stabilized silver nanoclusters (DNA-AgNCs) are a new class of biocompatible, fluorescent nanostructures that have recently been demonstrated to offer promise as biosensors. In this work, we identify two different DNA sequences which form dopamine-sensitive nanoclusters. We demonstrate that each sequence supports two distinct DNA-AgNCs capable of providing specific, ratiometric fluorescent sensing of dopamine concentration in vitro. DNA-Ag nanoclusters therefore offer a novel, low-cost approach to quantification of dopamine, creating the potential for real-time monitoring in vivo.

Advances in nanomaterials for brain microscopy

“…Recently, DNA-stabilized silver nanoclusters (DNA-AgNC, excitation: 495–575 nm, emission: 500–800 nm) have also been shown to be effective fluorescent sensors of neurotransmitters, such as dopamine [168]. The fluorescence of select DNA-AgNCs was found to either increase or decrease upon the addition of dopamine either pre-synthesis, for in vitro sensing, or post-synthesis for potential in vivo sensing applications.…”