想在黑夜中也能根據熱信號「看」到別人，但又不想戴夜視鏡？未來某天，生物技術可能真能實現你的間諜夢：研究人員已經研發出了一種可注射納米天線，能讓小鼠看見超出它正常視覺範圍外的紅外光。相關研究發表在《細胞》（Cell）雜誌上。和所有哺乳動物一樣，人類只能看到可見光譜中的光，包括彩虹的所有顏色。這種限制源自我們眼睛中的感光器，它只能檢測到波長在400~700納米左右的光，這也就意味著我們看不到波長更長一點的紅外光和近紅外光。
這引起了科學家的興趣。
「我們總是很好奇：有沒有什麼方法或技術能讓我們看見近紅外或紅外光呢？」中國科學技術大學的薛天說道。
薛天聯繫了麻省大學（University of Massachusetts）醫學院的同事韓綱，韓綱設計了一個非常微小的設備，他稱之為「上轉換納米粒子」（up-conversion nanoparticle）。
韓綱：「我們研發出了一種納米粒子，即所謂的上轉換納米粒子，能被這種近紅外光有效地激活。」
他們接下來在小鼠身上測試了這一系統，納米粒子會自動附著在小鼠視網膜中的光感受器上，吸收紅外光並將其轉換為可見的綠光。
韓綱：「這種綠光能視網膜細胞吸收。」
然後大腦會將它處理成常規的可見光。
這種增強後的「超級視覺」不僅能讓動物看見紅外光，還能讓它們……[查看全文]
Eye Treatment Stretches Mouse Sight Beyond Visible Spectrum
Tired of having to reach for your night-vision goggles when you want to track someone's heat signature after dark? Well, biotech may someday come to the rescue for all of you aspiring spies. Because researchers have developed an injectable, nanoscale antenna, which they've used to allow mice to see beyond their normal visual spectrum and into the infrared. The work appears in the journal Cell.
Like all mammals, we humans are only able to see light in the visible spectrum, which includes all of the colors of the rainbow. That limitation is due to the photoreceptors in our eyes being only able to detect radiation with a wavelength of around 400 to 700 nanometers. Which means we can't see infrared and near-infrared light, which has wavelengths a little bit longer.
And that got scientists thinking.
"So we always curious on whether we can use any method or technique to allow us to be able to see near-infrared or infrared light."
Tian Xue of the University of Science and Technology of China. He reached out to his colleague Gang Han at the University of Massachusetts Medical School, who engineered a teeny tiny device, which he calls an "up-conversion nanoparticle."
[GH]: "We actually developed nanoparticles, so-called up-conversion nanoparticles, that actually can effectively be activated by this near-infrared light."
Then they tested their system in mice. The nanoparticles attach themselves to photoreceptors in the animal's retina. There, they absorb infrared radiation and convert it to visible green light.
[GH]: "This green light is absorbed by retinal cells."
Which the brain then interprets as regular visible light.
This enhanced super-vision allows the animals to not only see in infrared, but to...[full transcript]