Surface oxidation of carbon dots enables highly selective and sensitive chemiluminescence detection of hydroxyl radical

The rapid quantification of hydroxyl radical (<middle dot>OH) in real samples is a great challenge due to its highly reactive nature and the potential interferences from other coexisting reactive oxygen species (ROS). Herein, a chemiluminescence (CL) probe (ox-CDs) was rationally developed for the detection of <middle dot>OH through controlled oxidation treatment of original CDs (o-CDs) with H2O2. Post-oxidation of CDs can reduce the surface defects or functional groups on the CDs, exposing reactive sites capable of effectively reacting with <middle dot>OH. The chemical energy generated from redox reaction between <middle dot>OH and the ox-CDs can be efficiently utilized to generate strong and selective CL responses to <middle dot>OH without interferences from other ROS. Thus, a highly selective and sensitive CL method with a linear range from 0.01 to 150 mu M and a detection limit of 3 nM was developed, which was successfully applied for monitoring the <middle dot>OH production from cigarette and mosquito coil smoke.