Photoreceptor degeneration is an important cause of blindness. Nelidova et al. used tunable, near-infrared sensors to render diseased photoreceptors light sensitive again. They used gold nanorods capable of detecting infrared light that were coupled with an antibody to temperature-sensitive ion channels. When the nanorods absorbed light and converted it into heat, the coupled ion channels were gated by infrared light.
In a mouse model of retinal degeneration, the temperature sensitive ion channels were successfully targeted to cone photoreceptors, and responses to near infrared light could be detected. In the primary visual cortex, more cells responded to near-infrared stimuli in mice expressing these ion channels than in controls. By changing the length of the gold nanorods, the system could be tuned to different infrared wavelengths.
See their Science published articles; Unblinding with infrared nanosensors, Restoring light sensitivity using tunable near-infrared sensors