Chemiluminescence from singlet oxygen under laminar flow condition in a micro-channel

Singlet oxygen was generated by reaction of sodium hypochlorite and hydrogen peroxide in a micro-channel. The two reagent solutions were delivered into the micro-channel by syringe pumps, providing a laminar flow. Such a laminar flow forms a liquid–liquid interface instantly in a micro-channel, and then the interface collapses gradually through molecular diffusion with the residence times. The chemiluminescence from the singlet oxygen was emitted in the course of the collapse of the interface under laminar flow condition. The chemiluminescence intensity was observed continuously and stably in the micro-channel as long as the reagents were fed into the channel. We examined the features of the chemiluminescence emitted in the micro-channel by changing the flow rates of reagents and the detection points in the micro-channel. The data obtained were considered along with the residence times and diffusion lengths. We also examined the effects of antioxidants, such as sodium azide, histidine, nitroblue tetrazolium, and 2-propanol on the chemiluminescence intensity.