Fabrication of Porous Non-Enzymatic Glucose Sensing Electrodes Through Nanosecond-Laser Patterning of Metal-Organic Frameworks

Nanosecond laser patterning of Copper Metal-Organic Framework (Cu-MOF) coated substrates is performed to fabricate non-enzymatic glucose sensing electrodes. The Cu-MOF coated glass substrate with a cover glass is subjected to a laser patterning process; the amount of MOF, laser fluence, and scan speeds mainly influenced the patterning process. The electrodes are fabricated on coated and covered glass with varying electrical conductivity due to the high laser energy absorptivity. The patterned electrodes consist of graphitic carbon incorporated with nano-Cu and show a stable electrical conductivity on the coated substrates. The electrodes are chemically active in the Fe2+/Fe3+ redox system; however, their activity varies with patterning conditions. The electrochemical studies in alkaline electrolytes reveal that the as-fabricated electrodes can sense the glucose molecule in the linear concentration range of 0.025-1.0 and 1.0-10.0 mm, with a maximum sensitivity of 3260.3 mu A mM(-1) cm(-2) and a response time of no more than 5 s, and a limit of detection (LOD) of 0.25 mu m. The current recovery rate is higher (> 80%) when adding glucose molecules than when adding other interference molecules, confirming that the electrode is selective toward glucose sensing. The results reveal that the fabricated electrodes act as stable, reusable, non-enzymatic glucose-sensing electrodes.