Miniaturized ECL detection system for glucose biosensor

In the biosensor detection techniques, electrochemiluminescence (ECL) has been investigated in analytical chemistry due to its inherent high sensitivity and wide linear working ranges. The conventional ECL detection system which usually requires optical inspection device has the disadvantages of high cost, high power dissipation and large size. In order to overcome these problems, we have investigated the integrated micro-ECL detection system based on silicon photodiode, which is integrated with SAM (self-assembled monolayer)-coated electrochemical electrode and microfluidic channel. The interdigitated electrodes have been used to generate uniform electrical field on the electrochemical electrode. SAM-coated interdigitated electrodes was bonded the PDMS micro-channel fabricated by replica molding process. To analyze glucose concentration in micro-ECL system with microfluidic channel, we determined the optimum conditions of ECL electrode potential, luminol concentration and flow rate. After optimization of the working condition, a series of measurements were performed with artificial glucose concentrations range from 1 mM to 10 mM in the integrated micro-ECL system. The photocurrent was proportional to glucose concentration from 1 mM to 10 mM. Also, ECL reaction was evaluated by photodiode in micro system with 0.95 μl. Therefore, we confirmed possibility of integrated ECL detection system for glucose biosensor.