Hybrid AuNP@GCD nanosensor for dual mode dopamine detection and imaging in drosophila brain

Abstract

In this work, we have constructed a surface passivated green carbon dot (GCD) integrated with boronic acid functionalized gold nanoparticle (AuNP@GCD) FRET nanoprobe for selective detection of dopamine through both fluorescence and electrochemical dual methods. The intense blue FL emission of GCD was decreased after integration with AuNP. The feeble FL emission of AuNP@GCD gradually increased when comes in contact with dopamine due to strong diol-boronic acid interaction and restriction of energy transfer. In the meantime, there was an 18-fold increment in the current response of the AuNP@GCD deposited electrode towards dopamine as compared to bare GCE. The remarkable integration of conductance and fluorescence properties makes our probe suitable for dual sensing of dopamine in human blood samples. The detection limits for the fluorescence and electrochemical detection are 0.025 and 0.00026 µM respectively. Further, a detailed analysis of toxicity induced by the probe and imaging properties in a fruit fly model (Drosophila melanogaster) suggests that the AuNP@GCD probe is safe and may further find application for dopamine imaging in brain.