Multi-Cell Array of Nanogap Electrodes for Label-free Detection of Biomolecules

Abstract

Impedimetric biosensors are predominantly used for in vitro device applications due to their portability. However, these devices suffer from thermal noise due to electric double layer (EDL) at low frequencies (<100 KHz). Hence, we disclosed a novel multi-cell nanogap electrode array with nanogap size (~100 nm) electrode to reduce this parasitic noise from EDL. Thus, it increased the sensitivity of detection of interested biomolecules. The proposed electrodes are fabricated on the SiO 2 substrate using Aluminum (A1) electrodes with the passivation of Hafnium oxide (Hf02) on it. We evaluated the fabricated electrodes in potassium chloride (KC1) solution to determine the sensitivity of the sensor with decreasing of the gap between the electrodes. Hence, the electrode with the smallest gap size (~100 nm) is evaluated for the determination of hybridization of TNF-αprotein to demonstrate the biomedical application of the developed sensor.