Dual-channel Online Optical Detection Platform Integrated with a Visible Light Absorption Approach for Continuous and Simultaneous In Vivo Monitoring of Ascorbic Acid and Copper (II) Ions in a Living Rat Brain

Continuous recording of the dynamic changes of multiple physiologically neurochemicals in vivo is vital to understand the molecular basis of brain functions. For instance, disentangling the complicated interrelationship between ascorbic acid (AA) and copper ions (Cu2+) in signal transduction and homeostasis remains essential in understanding the pathology of hypoxia damage and neurodegenerative diseases. Unfortunately, to the best of our knowledge, there is still no report regarding the development of online and in vivo electrochemical or optical methods that can simultaneously measure AA and Cu2+ due to the limitation of different detection mechanisms and environmental conditions. In this work, we report a parallel dual-channel online optical detection platform (OODP) for the continuous and simultaneous monitoring of AA and Cu2+ in a living rat brain by integrating a capillary-based microfluidic system as well as an optical detector built under a bright-field microscope. Two kinds of colorimetric sensors...