 This study presents a new type of carbon-depth, CD, with a unique combination of features. The CDs have been designed to emit in the near-infrared 2, NIR2, region, which allows them to penetrate deeper into tissues than traditional CDs. Additionally, these CDs have been shown to have high quantum yields, meaning they produce more light per unit mass than other types of CDs. This makes them ideal for in vivo imaging applications such as monitoring pH levels in the stomach. This article was authored by Chao Chao Ci, Yuan Yuan Wang, Ben Wu, and others.