2-Aminophenylboronic acid-functionalized carbon dots show broad-spectrum antiviral activity against respiratory viruses.

Respiratory viruses such as influenza A virus (IAV), respiratory syncytial virus (RSV), and human metapneumovirus (hMPV) impose a persistent global health burden, yet current antivirals are often limited by toxicity and side effects. This highlights the urgent need for broad-spectrum antiviral agents that can safely block viral infections. Carbon dots (cDots) provide an ideal scaffold for this strategy due to their ultra-small size, tuneable surface chemistry, and inherent biocompatibility. Notably, we previously demonstrated that 2-aminophenylboronic acid (APBA)-derived cDots have virus-binding capabilities by inhibiting human immunodeficiency virus (HIV)-1 entry. Herein, we synthesize APBA-functionalized cDots via pyrolysis, yielding cDots densely decorated with boronic acid and boroxine groups. These non-toxic APBA-cDots demonstrate potent antiviral activity against RSV, IAV, and hMPV in vitro. Competitive inhibition by N-acetylglucosamine and molecular docking analyses are consistent with a proposed boronic acid-mediated interaction with glycan-rich viral surfaces, although this mechanism has not yet been definitively proven by direct loss-of-function chemistry. Overall, these findings identify APBA-cDots as a promising antiviral nanoplatform and provide preliminary support for a glycan-targeting mechanism that warrants further validation.