Label-free biochemical sensor for hydrogen peroxide detection enabled by a misaligned square coreless fiber

Hydrogen peroxide (H2O2) is a common chemical substance that is widely used in many industries. Within a certain concentration range, hydrogen peroxide is hazardous and toxic. Therefore, it is crucial to accurately determine the concentration of hydrogen peroxide for safety and diagnostic purposes. Herein, a label-free biochemical sensor is proposed and experimentally demonstrated for highly efficient H2O2 detection. The biosensor is based on a misaligned square coreless fiber, which is fabricated using ultrasonic vibrational cutting technology. The surface of the square coreless fiber is functionalized with catalytic enzymes through covalent bonding, allowing for the accurate detection of H2O2 concentration. The experimental results show that label-free biochemical sensor exhibits a sensitivity of 0.0083 nm/μM within the H2O2 concentration range of 0-800 μM. A low limit of detection of 7.95×10-4mol/L is also obtained during the detection of H2O2solution. Furthermore, the developed optical sensor provides a biochemical platform for determining enzyme-catalyzed reactions and can be applied in the fields of food safety, health monitoring, and environmental protection.