A Multi‐Channel Handheld Diagnostic Device Based on Green Biomimetic Material for Point‐of‐Care Testing of Vitamin C in Human Fluids

Abstract In the era of “Great Health”, maintaining an appropriate level of vitamin C is crucial for human health as it directly impacts the proper functioning of the immune system. In this study, a handheld nonenzymatic electrochemical sensor based on biomimetic material prussian blue functionalized polydopamine is proposed for point‐of‐care testing (POCT) of vitamin C in human fluids. Particularly, Prussian blue, known as a bio‐antidote, and polydopamine, a main component of cuttlefish ink, ensure the safety and reliability of home testing. The experimental results quantitatively demonstrate that this electrochemical POCT sensor enables rapid and accurate determination of vitamin C with a wide linear detection range from 0.2 to 200 µ m , a low limit of detection at 0.03 µ m , and high sensitivity at 0.33 µA µ m −1 cm −2 . More importantly, the performance evaluation using human urine and saliva samples confirms satisfactory accuracy and recovery rates for vitamin C determination by this electrochemical POCT sensor. Thus, the proposed handheld electrochemical POCT sensor holds potential utility as an affordable tool for VC determination and home‐based healthcare.