A biosensor is an analytical device

A biosensor is an analytical device used for the detection of analytes, which combines a biological component with a physicochemical detector[11]. Recently, an increasing number of biosensors have been used in clinical research, for example, the blood glucose biosensor[12,13]. Most of the clinical research on biosensors was based on immunological reaction or DNA hybridization, and the sensor always gave rapid results with a high sensitivity[14,15]. DNA biosensors based on nucleic acid hybridization are currently under intense investigation owing to their increasing importance in the diagnosis of disease, with low cost and low power requirements[16]. This type of biosensor can be prepared by immobilizing single-stranded DNA probes on different electrodes and physicochemical detectors are used to measure the hybridization events between the DNA probes and their cDNA fragments.