Controllable stationary photocurrents generated from a bacteriorhodopsin/upconversion nanoparticle-based...

Area of Science:

• Biophysics
• Nanotechnology
• Optoelectronics

Background:

• Bacteriorhodopsin (bR)-based devices aim for photocurrent generation and artificial retinas.
• Controllable, infrared-triggered photocurrents remain an unmet challenge.

Purpose of the Study:

• To develop a novel bionanosystem for infrared-triggered photocurrent generation.
• To achieve controllable photocurrent amplitudes using upconversion nanoparticles (UCNPs) and bR.
• To explore the potential for new bR-based optical devices and fundamental bR photoresponse studies.

Main Methods:

• Synthesis of NaYF4:Yb,Er and NaYF4:Yb,Tm upconversion nanoparticles (UCNPs) with green and blue emissions.
• Incorporation of UCNPs with bacteriorhodopsin (bR) to create a bionanosystem.
• Utilizing 980 nm near-infrared (NIR) irradiation to trigger UCNP emissions and initiate the bR photocycle.

Main Results:

• NIR irradiation of the bionanosystem generated a stationary photocurrent.
• UCNPs acted as internal light sources, accelerating the bR photocycle.
• Photocurrent amplitude was controllable by adjusting the blue/green emission intensity ratio.

Conclusions:

• The developed bionanosystem successfully achieved controllable, infrared-triggered photocurrent generation.
• This system demonstrates significant potential for advanced bR-based optical devices and artificial retinas.
• The study provides valuable insights into the fundamental mechanisms of bR photoresponse.