Nanoengineering InP Quantum Dot-Based Photoactive Biointerfaces for Optical Control of Neurons

Area of Science:

• Biomedical Engineering
• Neuroscience
• Materials Science

Background:

• Light-activated biointerfaces offer non-genetic control of neural activity.
• Indium phosphide (InP) quantum dots (QDs) are promising for biointerfaces due to tunable properties, photostability, and being heavy-metal-free.
• The impact of QD nanostructure and biointerface design on photoelectrical cellular interfacing is not well understood.

Purpose of the Study:

• To investigate how nanoengineering at both the quantum dot (QD) and device levels controls the photoelectrical response of InP QD-based biointerfaces.
• To explore the potential of engineered InP QD biointerfaces for precise neural stimulation.

Main Methods:

• Synthesized InP quantum dots with varying nanostructures, including the addition of a thin ZnS shell.
• Engineered the band alignment of the QD-biointerface to control photoelectrochemical current generation.
• Tested the biointerfaces on primary hippocampal neurons to assess neural activity modulation.

Main Results:

• A thin ZnS shell (approximately 0.65 nm) on InP QDs increased biointerface current by over an order of magnitude compared to bare InP QDs.
• Device-level band alignment engineering enabled bidirectional photoelectrochemical current generation.
• Light-induced, temporally precise, and rapidly reversible action potential generation and hyperpolarization were achieved in neurons.

Conclusions:

• Nanoengineering of InP quantum dots and their biointerface architecture is critical for optimizing photoelectrical cellular interfacing.
• Engineered InP QD biointerfaces can achieve precise, bidirectional control of neural activity using light.
• These findings highlight the significant potential of nanoengineered QD biointerfaces for next-generation neurostimulation technologies.